lo s pe ñasq uitos lagoon sediment/siltati mdl€¦ · u. lo se city of s. env s pe dim san d...
TRANSCRIPT
U.
LoSe
City of
S. Env
os Peedim
f San D
ironme
Fina
eñasqment/S
Pre
Diego, S
ental Pr
Pre
al - Oct
quitoSiltati
epared for:
Storm Wand
rotectio
epared by:
tober 2
os Lagion T
Water D
on Agen
20, 201
goonTMDL
Departm
ncy Reg
10
n L
ment
gion IX
1
Table oExecutiv
1 Intro
2 Prob
3 Bac
3.1
3.2
3.3
3.4
4 Num
4.1
4.1.
4.1.
4.1.
4.1.4
4.1.
4.2
4.3
5 Data
5.1
5.2
6 Sou
6.1
6.2
6.2.
6.2.
6.2.
6.3
7 Link
7.1
7.2
of Contenve Summar
oduction ....
blem Statem
ckground In
Los Peñas
Los Peñas
Applicable
Impairmen
meric Targe
Land Use C
1 Los Pe
2 Tidal P
3 Waste
4 Waters
5 Habita
Impacts of
Selection o
a Inventory
Streamflow
Suspended
urce Assess
Land Use /
Point Sour
1 Phase
2 Phase
3 Caltran
Nonpoint S
kage Analys
Model Sele
Technical C
nts ry ..............
.................
ment .........
formation ..
squitos Wat
squitos Lago
Water Qua
nt Descriptio
ets .............
Changes in
eñasquitos
Prism Restr
water Efflu
shed Sedim
at alteration
f Urbanizati
of TMDL Nu
y and Analy
w Data Sum
d Sediment
sment ........
/ Sediment
rces ...........
I Municipa
II Municipa
ns MS4s ...
Sources .....
sis .............
ection Crite
Criteria .....
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tershed Des
oon Descri
ality Standa
on .............
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n the Los P
Lagoon His
riction ........
ent Discha
mentation ..
s ...............
on on Wate
umeric Targ
sis ............
mmary .......
t Data Sum
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Source Co
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al Separate
al Separate
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eria ............
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scription ...
ption .........
ards ...........
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eñasquitos
storical Wa
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rge ...........
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er Quality ..
get ............
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mmary ........
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orrelation ...
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Storm Sew
e Storm Sew
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Watershed
ater Quality
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wer System
wer System
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7.3
7.4
7.4.
7.4.
7.5
8 Iden
8.1
8.2
8.3
8.4
8.5
8.6
8.7
8.8
8.9
9 Tota
9.1
9.2
9.3
10 Re
Appendi
Regulatory
Model Sele
1 Waters
2 Lagoo
Model App
ntification o
Loading An
Application
Load Estim
Identificatio
Critical Loc
Calculation
Margin of S
Seasonalit
Daily Load
al Maximum
Wasteload
Load Alloc
Summary o
eferences .
ix A: Los P
y Criteria ...
ection and O
shed Mode
n Model: E
plication .....
f Load Alloc
nalysis ......
n of Numeri
mation .......
on of Critica
cations for T
n of TMDLs
Safety .......
ty ...............
d Expressio
m Daily Loa
d Allocations
cations .......
of TMDL R
.................
Peñasquitos
.................
Overview ..
el: Loading
Environmen
.................
cations and
.................
ic Targets .
.................
al Condition
TMDL Calc
s and Alloca
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n ..............
ads and Allo
s ...............
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esults .......
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s Lagoon S
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Simulation
ntal Fluid Dy
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d Reduction
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ns .............
culation .....
ation of Loa
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ocations ....
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Sediment TM
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n Program i
ynamics Co
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ns .............
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ads ............
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MDL Model
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n C++ (LSP
ode (EFDC
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ling – Final
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PC) ...........
C) ...............
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Report
3
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Figure
Figure 1Figure 2Figure 3Figure 4Figure 5Figure 6Figure 72010) ...Figure 8Figure 9Figure 1Figure 1Figure 1Figure 1Figure 1Figure 1Figure 1Figure 1Figure 1Figure 1Figure 2events ..
TablesTable 1.Table 2.Table 3.Table 4.
s:
. Location 2. Municipa3. Los Peña4. Land use5. Land use6. Photogra7. Wetland .................
8. Timeline 9. Timeline
0. Historic1. Major ro2. San Die3. Nationa4. Nationa5. LPL En6. Historic7. Hydrog8. Monitor9. Cumula
20. EMC/M.................
s: Beneficia Current (S TMDL su Current v
of the Los alities withinasquitos waes in the Loe distributioaph of Los Phabitats wi.................of urbanizaof urbaniza
c land use inoads withinego regionaal Wetland Ial Wetland Ihancement
cal lagoon wraph for Loring locationative flow vo
Median TSS .................
l uses desigSANDAG 2mmary ......s. historica
Peñasquiton the Los Patershed elos Peñasquon in the LoPeñasquitoithin Los Pe.................ation and laation and lan the Los P
n the Los Peal populatioInventory (NInventory (Nt Plan – 19
wetland typeos Peñasquns in the Loolumes at Tand 95th p
.................
gnated for 2000) vs. his.................l loads and
os watersheeñasquitosevation .....
uitos waterss Peñasqu
os Lagoon .eñasquitos .................agoon trendagoon trendPeñasquitoseñasquitos
on trends (SNWI) - 1985NWI) - 200985 wetlandes (Mudie eitos Creek
os PeñasquTMDL monipercentile c.................
Los Peñasqstorical land................. percent re
ed .............s watershed.................
shed ..........itos waters.................Lagoon (C.................ds (1800s tds (mid 197s watershedwatershed
SANDAG, 25 ...............9 ............... types .......et al. 1974).................
uitos watersitoring locat
confidence i.................
quitos Lagod use comp.................
eduction .....
.................d ..................................................hed ...........................
California St.................hrough ear
70s throughd (1970’s) ................
2010) ............................................................) .................................shed ..........tions .........intervals fo.................
oon ...........parison .......................................
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.................
.................ate Parks, .................
rly 1970s) ..h current) ............................................................................................................................................................................r all sampli.................
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4
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... 15
... 16
... 17
... 17
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... 24
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... 32
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... 33
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... 35
... 39
... 40 ng ... 41
... 20
... 27
... 59
... 59
Abbrev
BAT: BMP: CWA: CFR: EFDC: EMC: USEPALA: LSPC: MLS: MOS: MS4: NPS: NPDESSANDAGTBELs: TMDL: TSS: TWAS: USGS: WQOs: WLA: WDRs: WQBEL
viations:
:
: G:
Ls:
Best AvaBest ManClean WaCode of FEnvironmEvent MeUnited StLoad AlloLoading SMass LoaMargin ofMunicipaNonpoint National San DiegTechnoloTotal MaxTotal SusTemporaUnites StWater QuWasteloaWaste Di Water Q
ilable Technagement Pater Act Federal Reg
mental Fluidean Concetates Envir
ocation Simulation ading Statiof Safety l Separate Source PoPollutant Do Associati
ogy Based Eximum Dailspended Sory Watershates Geolo
uality Objecad Allocatioscharge Reuality Base
nology Practice
gulations s Dynamic ntration ronmental
Program inon
Storm Sewollution Discharge Eion of GoveEffluent Limy Load
olids ed Assessm
ogical Survectives n equiremented Effluent L
Code
Protection
n C++
wer System
Eliminationernments
mitations
ment Statioey
ts Limitations
Agency
n System
ons
(WQBELs))
5
ExecutThe purpDaily LoSedimenthe oceaprocessdevelopas impaSegmen The purpbeneficiaallocatioand natuassimilaTMDL recan recestrategypollutiondivided u Based oLagoon,the Lagobeing imquality salteratiosedimensuch asHabitatsimpacte In order numericsupporteavailableimpacts met WQthe acceWQOs.
tive Sumpose of this
oad (TMDL)ntation withan and the es. As reqed to addreired for sed
nts.
pose of a Tal uses in t
ons (WLAs)ural backgr
ate pollutantepresents teive and stiy for meetinn sources. up and allo
on historical the San Doon on the
mpaired (i.estandards an does not
ntation with, Estuarine
s of Speciald by the im
to calculatec target wased the desige literature to the Lago
QOs. Existineptable net
mary s technical ) for sedimehin the LagoLagoon, anuired by Seess sedimediment on th
TMDL is to ahe waterbo) for point soround [40 Ct loading (i.he maximull attain wag WQOs byOnce this m
ocated amo
l and curreniego RegioCWA Secti., does not
are narrativecause a nuin the Lago(EST), Ma Significanc
mpairment is
e a TMDL fs selected bgnated benthat descrioon over timng and histannual sed
report is to entation/siltoon has resnd degradedection 303(dntation withhe 1996 CW
attain wateody. A TMDources and
CFR 130.2] e., the load
um amount ter quality sy allocatingmaximum png all of the
nt accountsonal Water Qion 303(d) Lmeet applic
e in nature uisance or aoon threatenrine Life Hace (BIOL). s discussed
for sedimenbased on hineficial usesbes the patme was useorical land diment load
present thetation in Losstricted the d salt marsd) of the Clhin the LagoWA Section
r quality obDL is defined load allocasuch that th
ding capacitof the pollustandards.
g quantitativpollutant ame contributin
s of sedimeQuality ConList of Watecable wateand ensureadversely ans critical habitat (MARAdditional
d in Section
nt, a numerstorical cons of the Lagttern of urbaed to identifuse conditi
d that the La
e developms Peñasquitidal prism
sh habitats tean Water oon, which
n 303(d) Lis
bjectives (Wed as the suations (LAshe capacityty) is not ex
utant of con Additional
ve limits for mount has bng sources
ent-associatntrol Boarder Quality Lr quality stae that sedimaffect benefhabitat areaR), and Pres
informationn 3.3.
ric target munditions thagoon. A hisanization wfy the time ions were tagoon could
ment of a Totos Lagoon, or exchanthrough varAct (CWA)was origina
st of Water Q
WQOs) that um of the ws) for nonpoy of the watxceeded. T
ncern that thly, a TMDL
r point and nbeen calculas in the wate
ted impacts(Regional
Limited Segandards). Sment accumficial uses.
as and beneservation on on benefic
ust be idenat met WQOstorical ana
within the waperiod whehen modeled assimilate
otal Maximun (Lagoon).nge betweerious ), a TMDL wally identifieQuality Lim
support waste load oint sourcesterbody to Therefore, ahe waterbo representsnonpoint ated, it is thershed.
s to the Board) plac
gments as Sediment wmulation or
Excessiveeficial usesof Biologicalcial uses
tified. A Os and alysis of atershed an
en the Lagoed to determe and still m
6
um n
was ed
mited
s
a dy s a
hen
ced
ater
e
l
nd oon mine meet
AvailablframewoframewoC++, LSCode, Esedimenreceivingcharacte A sourceLagoon.runoff dewatershfrom streexchang The TMDrelationsAn impliassumptand condevelop The TMDallocatioassignedmunicipastorm seDepartmLagoon and sedregulateCity of D There isto requirforth in tthrough stream b
e data wereork developork consistsSPC) and a EFDC). Thent loading tog water moeristics for t
e analysis w The mostelivered by ed. In parteam bank ege, and load
DL also incship betweecit MOS wations, includsideration oed for this s
DL is divideon (LA) for nd to point salities that aewer system
ment of Tranwas estimaiment trans
ed under theDel Mar and
s legal authore dischargthis TMDL. runoff gene
bank erosio
e used to cped to supps of a waterreceiving w
e watershedo the Lagooodel was usthis tidally-i
was performt significantthe storm dicular, fromerosion/bedds contribu
cludes a maen pollutantas includedding establof the overastudy.
ed among tnonpoint so
sources andare includem (MS4s) pnsportationated based sport. A tote Phase I Md the City o
ority and a ers to imple As previouerated fromon/bed scou
onfigure, caport sedimershed modewater moded model waon from thesed to simulnfluenced w
med to iden source idedrain syste
m open spacd scouring. ted by trans
argin of safet loads and
d through thishing the Tall predictiv
he waste loources, andd nonpoint sed in the Sapermit, MS4 (Caltrans) on modelin
tal WLA waMS4 permit f Poway), P
regulatory ement and usly noted,
m urbanizatiuring, land
alibrate, annt TMDL deel (based oel (based onas used to ce Los Peñaslate hydrodwaterbody.
ntify and quentified wasm to the Lace areas loc Additional sportation i
ety (MOS) t predicted w
he applicatioTMDL baseve capability
oad allocatid the MOS. sources. Id
an Diego Co4 Phase II pstorm wate
ng of wateras assigned
(San DiegoPhase II MS
framework monitor cosediment i
ion, scourinuse practic
nd validate aevelopmenn the Loadin the Envirocalculate exsquitos wat
dynamics an
antify the ss urban devagoon from cated belowsources in
infrastructu
to account water qualion of a numed on the 19y of the mo
on (WLA) f Load redu
dentified poounty Phaspermittees, er permit. Sshed runoff
d to the respo County, tS4 permitte
that empowmpliance ws transporte
ng of canyoces, and oth
a customizet. The moding Simulatonmental Fxisting and tershed, whnd sedimen
sources of svelopment a
the surrouw storm waclude wavere.
for the uncty of the rec
mber of con993 critical deling fram
for point souction requioint sourcese I municipand the Ca
Sediment lof, streambapective munhe City of S
ees, and Ca
wers the Rewith the requed to the im
ons below sher process
ed modelineling tion Prograluids Dynamhistorical
hile the Lagnt transport
sediment toand urban nding
ater outfallse action, tid
ertainty in tceiving wat
nservative wet period
mework that
urces, loadrements ar
s include thpal separatealifornia oading to thank erosionnicipalities San Diego, altrans.
egional Boauirements s
mpaired Lagtorm outfal
ses. A
7
g
m in mic
oon
o the
and dal
the ter.
, t was
d re e
e
he ,
the
ard set goon ls,
significawhich aranthropomay be LA for n The regunonpoinEliminatthan dresection 4and comlimitationQuality B In Califofrom poiNPDES federal NrequiremCalifornisedimenand NPD For eachcalculatewaterboColognepollutionenforcemand reguNonpoinImpleme(NPS Imregulatioapplies tflow, orcamendmengaged
ant amount re defined aogenic activreasonablyonpoint sou
ulatory framt sources.
tion Systemedged or fill 402, discha
mplying withns consistinBased Efflu
ornia, State int sources requiremen
NPDES perments are isia’s Porter Cnt to the LagDES constr
h TMDL whed, which isdy by “non
e Water Qun and servement of TMulation of nnt Source Pentation and
mplementation include, to dischargchard irrigatment operatd in these la
of the sedimas those acvities that my controlledurces of sed
mework for CWA secti
m (NPDES) materials,
arges of poh NPDES png of eitheruent Limitat
Waste Disto navigab
nts and CWrmits. Thesssued by thCologne Wgoon includruction and
here nonpos the maximpoint sourcality Contro
es as the prMDL LAs for
onpoint souPollution Cod Enforcemion and Enffor examples from agtion return ftions, and sand use ac
ment load rctions, condmay influenc. This TMDdiment to th
point sourcon 402 estaprogram tofrom a ‘‘pollutants to wermits. The
r Technologtions (WQB
charge Reqble waters oWA requiremse are referhe State pur
Water Qualityde municipaindustrial p
int sourcesmum amounce” dischargol Act applierinciple legar nonpoint surce pollutio
ontrol Progrment of the forcement Pe, runoff froricultural irrflow, animaseptic systetivities can
results fromditions, or cce the qual
DL establishhe Lagoon.
ces differs fablishes th
o regulate thint source’’waters of these permits
gy Based EfBELs).
quirementsof the Unitedments (NPDrred to as Nrsuant to thy Control Aal MS4 Phapermits with
are determnt of a polluges in orderes to both pal authority sources. Thon is contaam (NPS PNonpoint SPolicy). Noom farms arigation retual feeding oems. Individ
be held ac
m controllabcircumstanclity of the whes a WLA .
from the rege National he ‘‘dischar into ‘‘wate
he U.S. are s commonlyffluent Limi
(WDRs) fod States tha
DES requireNPDES reqhe authorityAct. Point sase I and IIhin the wate
mined to be utant that mr to attain Wpoint and noin Californihe State plained in the
Program PlaSource Polluonpoint sound urban durn flow, nu
operations, dual landow
ccountable f
ble water quces resultingwaters of the
for point so
gulatory fraPollutant Drge of a polrs of the U.authorizedy contain etations (TB
or dischargeat implemeements) seuirements.
y that is dessource disch
dischargerershed.
significantmay be contWQOs. Theonpoint soua for the apan and poliPlan for Ca
an) and theution Controrces that wevelopmen
ursery irrigamanure cowners and ofor attaining
uality factorg from e State andources and
amework forDischarge
lutant,’’ oth.S.” Under by obtaininffluent
BELs) or Wa
es of pollutaent federal rve in lieu o Such
scribed in harges of rs, Caltrans
, a LA is tributed to ae Porter-urces of pplication acy for contralifornia’s
e Policy for tol Program
warrant nt. This polation return mposting, sother persog sediment
8
rs
d that a
r
her
ng
ater
ants
of
,
a
and rol
the m
icy
soil ons
load
reductio Nonpoinand therexamplepermit. controlla In order that will dischargwaters. by the vperform reductiomonitoriwasteloa
The TMDby the wincludeshistoricaperiod (r
Table ES-1
TMDL WatershedOcean bouMOS Table ES-2
Sou
TMDL WatershedcontributionOcean bou(LA)
ns in affect
nt source direfore shoue of an uncoHydromod
able source
to meet thedescribe th
gers may taThe SLRP
arious discstudies by ns, and/or ng to assesad reductio
DL results awatershed cs sediment al load reprereference c
1. TMDL sumSource
d contribution (Wundary (LA)
2. Current vs.
urce
d n (WLA) undary
ted watersh
scharges fruld not be reontrollable ification and
es of sedime
e TMDL, a he regulatorake to reducP will descri
hargers to the dischamodify comss the effec
on.
are summacontribution loads from esents the condition).
mary
WLA)
. historical loaCurrent Load
(tons) 13,663 7,719
5,944
heds throug
rom naturaegulated. Snonpoint sed acceleratentation.
Sediment Lry and/or ence pollutantbe the pollumeet the argers to fill
mpliance reqctiveness of
arized in thein Tables Estorm surgestimated l
Critical W
ads and perced Histor
(t12
9
gh enforcem
l sources aSediment dediment soted erosion
Load Reducnforcementt loading anutant reducllocation. Tdata gaps,quirementsf the implem
e tables belES-1 and Ege, wave acload contrib
Wet Period Loa12,360 2,580 9,780
Implicit
ent reductionrical Load tons) 2,360 2,580
9,780
ment of WD
re considerischarged vurce that isvia storm w
ction Plan (t actions thand monitor ction actionsThe SLRP w refine the
s. The discmentation m
low. The ovES-2. The oction, and tibution from
ad (tons)
Load Red(tons1,305,13
+3,836 (inc
DRs and the
red largely via tidal excs not governwater runof
(SLRP) willat the Regieffluent ands that are rewill include TMDL and hargers wilmeasures a
verall WLAocean boundal exchanthe mid-19
Daily
uction s)
P
3 9
crease)
e Waiver Po
uncontrollachange is aned by a Mff are
be developonal Boardd/or receiviecommendprovisions required lol conduct
at meeting t
A is represendary (LA) ge. The
970s time
Load (tons) 59 12 46
Implicit
Percent ReducRequired
10% 67%
+39% (increa
9
olicy.
able, an S4
ped d and ng ed to
oad
the
nted
ction
ase)
1 InThe purpthat wasLagoon Section Lagoon degradehelp res Section boundarwater qu(WQOs)priority rWater Q The purpwaterbo(WLAs) backgrothe loadamount quality sallocatinmaximuthe cont The TMDthe follow
1) P2) N
a3) S
s4) L
re 1 40 CFR
trodupose of thiss developedis listed as 303(d) Listrestricts the
es critical satore the be
303(d) of thries for whicuality stand), and an anranking for
Quality Limit
pose of a Tdy. A TMDfor point sound, such ting capacitof the pollu
standards. ng quantitatm pollutanttributing sou
DL processwing seven
Problem StNumeric Ta
ttainment oSource Assources of th
Linkage Aneceiving wa 130.2
uctions technical d for sedimeimpaired fo
t of Water Qe tidal prismalt marsh haeneficial use
he CWA rech the effluards, whichntidegradatthese impated Segme
TMDL is to aDL is defineources, andthat the capty) is not exutant of conAdditionally
tive limits fot load has burces in the
s begins witn componen
atement – argets – ideof the WQOsessment –he impairin
nalysis – esater conditio
n report is to ent/siltationor sedimen
Quality Limim, or exchaabitats throes of the La
quires that ent limitatioh consist oftion policy. aired watersnts, and to
attain WQOed as the sud load allocapacity of thexceeded1. Ancern that thy, a TMDL or point andbeen calculae watershed
th the devents:
generally dentifies the
Os and prote– identifies g pollutant stablishes tons and ca
present then for Los Pent/siltation oted Segme
ange betweough variouagoon and a
each stateons are not f beneficial The CWA s, known asestablish T
Os that suppum of the inations (LAse waterbodA TMDL, thhe waterborepresents
d nonpoint pated, it is dd.
elopment of
describes imhistoric numection of beall of the knin the wate
the relationslculates the
e Total Maxeñasquitos on the Cleanents. Sedimen the oceas processeachieve wa
identify wastringent euses, watealso requir
s the CWA TMDLs for t
port beneficndividual was) for nonpoy to assimi
herefore, redy can rece a strategy pollution soivided up a
f a technica
mpairment meric targeeneficial usenown point ershed (Secship betweee Loading C
ximum DailLagoon (Lan Water Ac
mentation wan and the
es. A TMDLater quality s
aterbodies wenough to mer quality obres states toSection 30the identifie
cial uses inasteload alloint sourceslate pollutapresents theive and stifor meeting
ources. Oncand allocate
l analysis w
(Section 2)et which willes (Sectionsources an
ction 6) en pollutan
Capacity of
y Load (TMagoon). Th
ct (CWA) within the
Lagoon, anL is neededstandards.
within its meet applicabjectives o establish 3(d) List of
ed waterbod
the ocations s and naturant loading (he maximumill attain wag WQOs byce the total
ed among a
which includ
) l result in n 4) nd nonpoint
t sources athe waterb
10
MDL) he
nd d to
able
a fdies.
ral (i.e., m ater y l
all of
des
t
and ody,
wwu
5) M6) S
a7) A
slo
The writanalysisincludingWQOs aused to TMDL Imbeing deThis infoSedimenof the TM This TMthe Los and CityCoastkerepresenCity of Swatersh
which is the waterbody w
ses (SectioMargin of SSeasonal V
ccounted foAllocation oources in th
oad allocati
te-up for thes. This techg a descripand beneficcharacteriz
mplementateveloped. Tormation wint Load ReMDL.
MDL was dePeñasquito
y of Poway)eeper, Califontatives froSan Diego aed.
maximum without causon 7) Safety (MOSVariation anor in the TMof the TMDhe watersheons (LAs) f
e above cohnical reportion of the L
cial uses (Sze the impation SectionThis sectionll be updateduction Pla
veloped thros watershe), the Califoornia Statem the Regiand include
load of the sing exceed
S) – accound Critical MDL determDL – divisioed; wastelofor nonpoin
mponents irt also incluLagoon and
Section 3), aairment andn will be incn focuses oed in the fu
an (SLRP) t
rough closeed (City of Sornia Depar Parks, theonal Board
ed detailed
pollutant thdances of W
nts for unceCondition
mination (Sen of the TMoad allocatit and backg
is generallydes backgrd its watersand a discu associated
cluded lateron the Regiuture througthat will be
e collaboratSan Diego,rtment of Tr Los Peñas
d. This thirdmodeling o
hat may be WQOs and
ertainties ins – describection 8)
MDL amongons (WLAsground sou
y referred toround informshed, discusssion summd pollution sr, as this infonal Board
gh developmsubmitted f
tion betwee San Diegoransportatiosquitos Lagd party TMDof the Lagoo
dischargedimpairmen
n the analysbes how the
g each of ths) for point surces (Secti
o as the tecmation on tssion of themary of the sources (Seformation is
d’s regulatoment of a defor approva
en the munio County, Con (Caltransgoon FoundDL effort waon and its c
d to the nt of benefic
sis (Sectionese factors
e contributisources andon 9)
chnical TMDthe Lagoone applicable data that wection 5). Ts currently ry authorityetailed
al after adop
icipalities wCity of Del Ms), San Die
dation, and as led by thcontributing
11
cial
n 8) are
ing d
DL , e were The
y.
ption
within Mar, ego
he
2 PrUnder Swaters wPeñasquSegmenacres. T(USEPA The LagReservean approCanyon,Preservesalt marspecies variety omammaoffering coastal m The Sansedimencause nplan for (althougpreservahabitat, organismthat is mmay inclshellfish Impacts mixing wand salt industriaconstrictand Prohighlight
roblemSection 303whose beneuitos Lagoonts in 1996 The LagoonA, 2009).
goon is an ee. In additiooximately 6, Los Peñase” by the Crsh lagoons(California
of plant speal population
migratory bmarine spe
n Diego Basnt dischargeuisance or the lagoon
gh access isation of biolrare, threat
ms, and spamost sensitivlude preser
h, or wildlife
associatedwithin Lagoo
marsh vegal developmtion of a magram (1985t sedimenta
m Sta(d) of the Ceficial uses on was placfor sedime is subject
estuarine syon to its mar60,000-acresquitos Can
California Sts in souther
State Parkecies, and pns. The Lagbirds a safeecies that us
sin Plan stae rate of suadversely ainclude co
s not permitlogical habtened or enawning, repve to increarvation or e (such as m
d with increon channel
getation, incments, turbidain wildlife c5), San Dieation as a s
atemeClean Wate
have beenced on Sectntation andto the deve
ystem that rine influen
e watershednyon, and Cate Parks,
rn Californiaks, 2009). Tproviding hagoon also se place to rese the Lago
ates, “The srface wateraffect benentact watertted in somitats of spe
ndangered sproduction ased sedim
enhancememarine mam
ased and ras, degrada
creased vuldity associacorridor. Thgo Basin P
significant im
ent r Act (CWA
n impaired dtion 303 (d)
d siltation welopment of
is part of thce, the Lagd comprisedCarmel Canthe Lagoon
a, providingThe Lagoonabitat for nuserves as aest and feeoon to feed
suspended rs shall not
eficial uses”r recreation
me areas pecial significspecies, maand/or ear
mentation isnt of estuar
mmals or sh
apid sedimtion and (inlnerability toated with sihe Los Peñ
Plan (1994),mpact asso
A), states ardue to spec) list of Wat
with an estimf a total max
he Torrey Pgoon receivd of three mnyon). Given is one of tg a home ton is ecologicumerous bir stopover fod, as well a and hide f
sediment lobe altered . Beneficia
n, non-contar California
cance, estuaarine habitaly developmestuarine h
rine habitathorebirds).
entation incn some caso flooding filtation in Laasquitos La, and Cleanociated with
re required cific constituter Quality
mated area ximum dail
Pines State ves freshwamajor canyoen the statuthe few remo several encally diverserd, fish, andor the Pacif
as providingrom predat
oad and suin such a m
al uses listeact water rea State Parkarine habitaat, migratioment. The habitat. Ests, vegetatio
clude: redues) net loss
for surroundagoon chanagoon Enhan Water Acth urban dev
to identify uents. Los Limited affected ofy load (TM
Natural ater inputs fons (Carrolls of “Natur
maining natindangered e, supportind small fic Flyway, g refuge forors.
uspended manner as ted in the baecreation ks), at, wildlife n of aquaticbeneficial u
stuarine useon, fish,
ced tidal s of riparianding urban nnels, and ancement Pt Section 30velopment a
12
f 469 DL)
from l al ive
ng a
r
to sin
c use es
n and
Plan 03(d) and
a leadinreductio Accordinwetland and mudThe Lagacres ofParks 20vegetatifreshwathabitats
1) In2) In3) De
These faincreasespecies. Developbeneficiasedimen
g cause in n a manag
ng to Califohabitats in
dflats), bracgoon’s 510 f freshwater010; see Fion has beeter or uplanin the Lago
crease in thcrease in secrease in
actors havees in freshw.
ping a sedimal uses of tnt accumula
the rapid loement prio
ornia State Pcluding coackish marshacres inclur wetlands agure 7). Th
en impairednd habitats.oon have b
he volume asediment dethe tidal pri
e led to decwater habita
ment TMDLhe Lagoonation.
oss of salt mrity.
Parks, the Lastal salt mh, riparian wdes approxare considehe remainin by sedime. The envir
been altered
and frequeeposition ism
creases in sats as well a
L for the Lag, including t
marsh habit
Lagoon conarsh (this in
woodland aximately 21ered unimpng 180 acreentation, coronmental pd by urban
ncy of fresh
saltwater anas increase
goon is necthe estuarin
tt in the Lag
nsists of apncludes sal
and scrub, a0 acres of taired (dataes of salt mnverting co
processes tdevelopme
hwater inpu
nd brackishes in the ab
cessary forne beneficia
goon, makin
pproximatelylt panne, tidand freshwatidal salt ma
a from Califomarsh and boastal salt mthat supporent in three
ut
marsh habbundance of
the restoraal use mos
ng sedimen
y 510 acresdal channelater marsh.arsh and 12ornia State
brackish mamarsh to rt wetland ways:
bitats and f non-native
ation of thet impacted
13
nt
s of s, . 20
arsh
e
by
3 BaThis secquality sinformat
3.1 LoThe LosBoth the(906), w(approxiDiego, Pis locatethat are
Figure 1.
ackgrction descristandards (ition on the
os Peñasqs Peñasquite watershedwhich also inimately 60,0Poway, anded in the ea
maintained
Location of th
roundbes the Losincluding beimpairment
quitos Wattos watershd and Lagoncludes Mis000 acres)
d Del Mar (Fastern headd by Caltran
he Los Peñasq
d Infors Peñasquieneficial ust.
tershed Dhed is locateon are inclussion Bay acoastal wa
Figure 2). Iwaters areans within th
quitos watersh
rmatiitos watershses and WQ
Descriptioned in centrauded in theand severalatershed incn addition, a. There ae watershe
hed
on hed and LaQOs), and p
n al San Dieg Los Peñas coastal trib
cludes portia small pore also sev
ed.
agoon, applprovides ba
go County (squitos Hydbutaries. Tions of the rtion of San
veral major
icable wateackground
Figure 1). drologic UnThis 93 mi2
cities of San Diego Coroad corrid
14
er
it
an unty ors
Figure 2. The clim65°F nealong thdry weatOctobernot falleinches othe annu Three mPeñasqu(approxisecond southernarea andCreek a
Municipalities
mate in the Rar the coase coast. Tther occursr 1 to April 3n for the pr
of rainfall (oual rainfall o
major streamuitos Creekimately 37,7largest catcn portion ofd drains thend Carroll C
s within the Lo
Region is gstal areas. here are th
s from May30 and has receding 72or greater) aoccurs duri
ms drain thek is the larg760 acres) chment (apf the waterse remainingCanyon Cre
os Peñasquito
generally mAverage anree distinct
y 1 to Septetwo types o
2 hours, andand the 72 ng the wint
e watershedest catchmthrough its
pproximatelyshed. Carmg 16 mi2 (apeek conflue
os watershed
ild with annnnual rainfat types of wember 30. Tof weather;d 2) wet wehour periodter season.
d and flow ment in the ws central poy 18 mi2 or
mel Creek ispproximatelence togeth
nual temperall ranges fr
weather in thThe winter ; 1) winter deather consd after the s
into the tidawatershed drtion. Carro11,520 acr
s located aly 10,240 ac
her prior to e
ratures averom nine tohe Region. season occ
dry weathersisting of stostorm. 85 to
al Lagoon (draining 59oll Canyon res) and dralong the nocres). Los entering the
eraging arouo 11 inches The summcurs from r when rainorms of 0.1o 90 percen
(Figure 2). mi2 Creek is th
ains the orthern, coa
Peñasquitoe Lagoon.
15
und
mer
n has nt of
Los
he
astal os
There isapproximimportedfrom sea
Figure 3. Data detDiego A4). Appthat areaPeñasqudensity rindustrialand usecharacteand with 2 http://www
s one majormately 1 mid drinking wa level to 2,
Los Peñasqui
tailing land Association
roximately a classifieduitos watersresidential al/transportaes in the waeristics thathin the mod w.sandag.org/r
r dam in thei2 (approximwater; does,600 ft in th
itos watershed
use in the of Governm54 percent as impervished is opedevelopmeation (approatershed is t are importdeling repor
resources/map
e Carroll Camately 640 s not dischae headwate
d elevation
Los Peñasments 2000 of the wateious. The len space (aent (approxioximately 1presented
tant for modrt (Appendix
ps_and_gis/gis_
anyon Creeacres) and
arge downsters (Figure
squitos wate0 land use cershed hasargest sing
approximatemately 14,2
11,660 acrein Figure 5del configurx A).
_downloads/do
ek watersheforms Miratream). Wa3).
ershed is avcoverage2 a been deve
gle land useely 25,500 a250 acres),es). The pe. Additionaration are d
ownloads/zip/L
ed, which dramar Reseratershed el
vailable thrand presenteloped, withe type in theacres), follo, and ercent distrial key watedescribed in
and/CurrentLa
rains rvoir (retainevation rise
rough the Sted in (Figuh 46 percene Los owed by low
bution of arshed
n later secti
nd/lu.zip
16
s es
San ure nt of
w
ll
ons
Figure 4.
Figure 5.
43
Land uses in
Land use dist
3%
1%2%
the Los Peñas
tribution in the
1%
6%
24
% 0%
squitos water
e Los Peñasq
3%
20%
4%
rshed
uitos watersh
Agric
Comm
High
Indus
Low D
Open
Open
Parks
Trans
ed
ulture
mercial Institut
Density Reside
strial/Transpor
Density Reside
n
n Recreational
s Recreational
sitional
tional
ential
rtation
ential
17
3.2 LoThe Losmi2 or 38Given thof the feecologicnumeroustopovespecies.
Figure 6. Tidal flowocean. closuresstorms sabutmenallow forsupport
os Peñasqs Peñasquit84 acres) thhe status ofew remainincally diverseus bird, fishr for migrat.
Photograph o
ws enter thCurrently, t
s are typicasurges and nts. Mechar tidal flow isalt marsh
quitos Lagtos Lagoon hat is part of “Natural Png native sae, supportinh, and smaltory birds a
of Los Peñasq
he Lagoon dthe Lagoonlly caused wave actio
anical dredginto the Lagspecies.
goon Descis a relative
of the TorrePreserve” byalt marsh lang a varietyl mammal pnd provides
uitos Lagoon
during perion mouth is oby coastal
on) and struging is usedgoon in ord
cription ely small es
ey Pines Stay the Califo
agoons in soy of plant sppopulationss habitat fo
ods when thopen througprocesses
uctures, sucd when neeer to impro
stuarine syate Naturalrnia State Pouthern Capecies, ands. The Lagr coastal m
he Lagoon ghout most (deposition
ch as the Ueded to elimve water qu
stem (appr Reserve (FParks, the Llifornia. Th providing hoon also se
marine and s
mouth is opof the year
n of sand an.S. Highwa
minate blockuality condi
roximately 0Figure 6). Lagoon is ohe Lagoon ihabitat for erves as a salt marsh
pen to the r. Mouth nd cobble
ay 101 kages and itions and
18
0.6
one is
Most of Carroll Cfreshwatthat flowsignificayear-rouCreek cochannel berm acmuch ofconnectthat recetwo smaCarroll Cevents.
3.3 ApWater qpolicy. Wwater quprotectiois requirassessmscientific The sedBasin (Bsuspendmanner 1994). Tdeveloppresentssedimen The BasLagoon applied tmaintain
the freshwaCanyon Creter to the L
wed year-roant rainfall eund due to ionfluences extends in
cts as a barf its length. ion betweeeives flow faller bridgesCanyon Cre
pplicable Wuality standWQOs are uality conston of benefred to publisments basecally sound
diment WQOBasin Plan)ded sedimeas to causeTo interpreted to estabs the detailent.
sin Plan ide(Regional Bto all benef
ned through
ater input fleek to the sagoon. Hisund, while
events. Begincreasing with Los Pto the Lago
rrier betwee The railroan eastern a
from Carmes located ineek to pass
Water Quadards considefined unituents or c
ficial uses osh water qud on curren water qua
O, as set fo, is narrativ
ent discharge nuisance t the narrat
blish the alloed informat
entifies the bBoard, 199ficial uses. hout the wa
ows througsouth and Cstorically, LCarroll Canginning in turban deve
Peñasquitosoon along then the eastead trestle aand westernel Creek cron the southes through to
ality Stanst of WQOsder Water C
characteristof water.” Uuality criterint scientific lity criteria,
orth in the Wve in naturege rate of su
or adverseive nature oowable sedtion that wa
beneficial u4) (Table 1 Complianc
aterbody to
gh Los PeñaCarmel Creeos Peñasqnyon and Che 1990s, t
elopment ws Creek upshe westernern and welong the non portions oosses throuern portion o the easter
dards s, beneficiaCode sectiotics which aUnder sectioa that incorinformationand be at l
Water Quali and statesurface wateely affect beof the sedim
diment loadas used to d
uses that ar). The narr
ce with WQprotect all b
asquitos Caek to the nouitos Creek
Carmel Creethese drainithin the wastream and side of thestern portio
orthern sideof the lagoough this areof the Lago
rn side of th
al uses, andon 13050(hare establison 304(a)(1rporate econ. WQOs mleast as str
ty Control Ps “The suspers shall noeneficial usment WQOing to the Ldevelop a n
re designaterative stand
QOs must bebeneficial u
anyon into orth also cok was the oeks only flowages also b
atershed. Cthe combin
e railroad traons of the Le provides ton. The Lagea. In additoon which ahe Lagoon d
d an anti-deh) as “limits hed for the 1) of the CWological andmust be basringent as th
Plan for thepended sedot be alteredes” (Region, a numeric
Lagoon. Senumeric targ
ed for Los Pdard for sede assesseduses.
the Lagoonontribute only tributarywed duringbegan flowiCarroll Canyned streamack berm.
Lagoon for he main goon channion, there aallow flow frduring high
egradation or levels oreasonable
WA, the USd human hesed on hose criteri
e San Diegodiment load d in such a nal Board, c target wasection 4 get for
Peñasquitodiment is d and
19
n.
y g ing yon
m This
nel are rom flow
f e
SEPA ealth
a.
o and
s
os
Table 1. BBeneficialREC 1
REC 2
BIOL
EST
WILD
RARE
MAR
MIGR
SPWN
SHELL
3.4 ImThe Lagsedimenimpairmmost seestuarinbuffer arimpairedof the 51coastal sParks, 2 As discureduced
Beneficial uses Use
Includeof watewater sspringsIncludeinvolvinincludetide pothe aboIncludeparks, where IncludepreservestuariIncludepreservreptilesIncludesuccesrare, thIncludeand enamphibIncludefresh afish. Includeearly dInclude(e.g., c
mpairment goon is listent/siltation iment impactsnsitive to ine and riparreas. The 3d. Recent s10 acres of salt marsh
2010). .
ussed in thed tidal mixin
s designated f
es uses of wateer is reasonableskiing, ski and s. *Note that aes the use of wng body contace, but are not limol and marine ove activities. es uses of watesanctuaries, ecthe preservatio
es uses of watevation or enhanne mammals, w
es uses of watevation and enhs, amphibians, es uses of watessful maintenanhreatened or enes uses of watenhancement of bians, invertebres uses of wateand salt water, o
es uses of wateevelopment of
es uses of wateclams, oysters a
Descriptied as impairmpacts thas several bencreased serian habitats303(d) listinsurveys by f coastal sato riparian
e problem sg within La
for Los PeñasB
er for recreatione possible. ThSCUBA divingccess to some
water for recreact with water, wmited to, picniclife study, hunt*Note that acce
er that support cological reseron or enhancemer that support ncement of estwaterfowl, shoer that support hancement of te
invertebrates),er that support nce of plant or ndangered. er that support terrestrial habirates), or wildlier that support or other tempo
er that support fish. This use
er that support and mussels) f
ion red on the C
at originate feneficial usedimentatios, includingng indicatesCalifornia Slt marsh hahabitat (Ca
statement, iagoon chan
squitos LagooBeneficial Use n activities invo
hese uses inclu, surfing, white
e areas is not ptional activities
where ingestioncking, sunbathiting, sightseeiness to some ardesignated are
rves, or Areas oment of naturalestuarine ecos
tuarine habitatsrebirds) terrestrial ecos
errestrial habita, or wildlife wathabitats necesanimal species
marine ecosystats, vegetationfe water and fohabitats neces
orary activities b
high quality aqe is applicable o
habitats suitabfor human cons
CWA Sectifrom waters
ses; howeveon. The Lagg coastal sas that an esState Parksas been impalifornia Sta
impacts assnels, degra
on Description
olving body conde, but are not water activitieermitted per C
s involving proxn of water is reang, hiking, bea
ng, or aestheticreas is not permea or habitats, of Special Biolol resources reqsystems includs, vegetation, fi
systems includats, vegetation,ter and food sossary, at least is established u
stems includingn, wildlife (e.g.ood sources. ssary for migratby aquatic orga
quatic habitats only for the proble for the collesumption, com
on 303(d) lshed sedimer, the estugoon’s wet
alt marsh hastimated ares indicate thpaired by seate Parks, 2
sociated wiadation and
ntact with watet limited to, swis, fishing, or usalifornia State ximity to water,asonable possiach combing, cc enjoyment in cmitted per Califsuch as establ
ogical Significaquires special ping, but not limish, shellfish, o
ing, but not lim, wildlife (e.g.,
ources. n part, for the s
under state or fe
g, but not limite, mammals, bir
tion, acclimatizanisms, such a
suitable for repotection of anadection of filter-femercial, or spo
ist due to ment contribuarine habitland habitaabitat and wea of 469 ahat greater edimentatio
2009; Califo
ith sedimen (in some c
er, where ingestmming, waddinse of natural hoParks but not normaible. These usamping, boatinconjunction witfornia State Palished refuges,
ance (ASBS), protection.
mited to, or wildlife (e.g.,
mited to, mammals, bird
survival and ederal law as
ed to, preservatrds, reptiles,
zation, betweenas anadromous
production and dromous fish. eeding shellfishort purposes.
butions. Thtat use is thats consist owetland/uplacres is than 180 a
on, convertiornia State
ntation inclucases) net l
20
tion ng, ot
ally ses ng, th arks
ds,
tion
n s
h
his he of and
acres ing
ude: oss
of wetlanassociathave inferosion processwithin thin increabelow sttransporflats, anthe yearand indi To addrebased aThe histwith natuassimila
nd vegetatited with siltfluenced theof canyon bes are exac
he watersheased runoff torm water rted downstd in Lagoonrs due to increctly affec
ess the imppproach wa
torical analyural sedime
ative capaci
on, converstation in Lage accumulabanks, bluffcerbated byed. Urban ddue to hydoutfalls thatream to then channelscreased se
cts lagoon fu
pairment, aas used to ysis focuseent loading ty, as desc
sion from sgoon chann
ation of sedfs, scouringy anthropogdevelopme
dromodifcatat dischargee Lagoon d. These se
ediment loadunctions an
nd interpretcalculate thd on identiffrom the w
cribed in the
saline to frenels. Thereiment withi
g stream bagenic disturnt transformtion resultine into canyoduring stormediment depding and innd salt mars
t the narrathe acceptabfying an ea
watershed we following s
shwater hae are many n the Lagooanks, and tirbances, sums the natung in scourinon areas. Sm events caposits haveadequate fsh characte
tive WQOs,ble sedimerlier time pe
which did nosection (Se
abitats, and potential s
on. Sourcedal influx.
uch as urbaural landscang of sedimSediment loausing depoe gradually bflushing, wheristics.
, a historicant load to theriod that cot exceed thection 4).
turbidity sources thates include Some of th
an developmape and resment, primaoads are osits on thebuilt-up ovehich directly
al watershedhe Lagoon.
correspondshe Lagoon’
21
t
hese ment sults rily
e salt er y
d-
s s
Figure 7.
Wetland habittats within Los Peñasquitos
s Lagoon (Callifornia State PParks, 2010)
22
4 NuWhen cawaterboprotectionarrative
The swaters
Due to tinterpretplanningthe attaiLagoon,‘referencimpairedloading the uniqthe Lagodeterminpast accthe relatLagoon referencin relatio8 and 9)approacperiod th(Sectionreferenc
umerialculating Tdy and subon of benefe and state
suspendeds shall not b
he narrativeted throughg purposes.nment of w a numeric ce watershed waterbodycapacity whue characteoon and its ning the cocounts of setionship betwater qual
ces was devon to chang). The linkach (Sectionshat could ben 4.4). Noteced in the h
ic TarTMDLs, numbsequently eficial uses. s:
d sediment lbe altered in
benef
e nature of h the develo. A numeric
water qualitytarget was
ed approacy to a similahich would eristics of twatershed
nditions thaedimentatiotween urbaity conditionveloped to ges in land age betwees 4.1 througe used calce that muchistorical tim
rgetsmeric targetestablish mThe sedim
load and sun such a maficial uses (
the sedimeopment of ac target is ny conditionss derived usch’ typicallyar-unimpairresult in thhe Lagoon, would prov
at support won impacts wanization in ns. A timeldocument iuse (urban
en these facgh 4.3) in oculate the nh of the bacmeline.
ts are selecmeasureablement WQO,
uspended sanner as to(Regional B
ent/siltationa numeric taneeded to ds. For the ssing a ‘refery refers to thred waterboe attainmen, it was detevide the bewater qualitwithin the Lthe watershline of signiimportant cization in pctors was erder to iden
numeric targckground in
cted to meee targets foas set forth
sediment dio cause nuisBoard, 1994
n WQO, thisarget for TMdefine the csediment/sirence watehe process ody to estant of water ermined thast informat
ty standardsLagoon werhed and asificant evenchanges in articular) avaluated usntify an appget for sediformation p
et the WQOor the restorh in the Bas
ischarge ratsance or ad4).
s WQO musMDL and imconditions tiltation imparshed approf compariblish an accquality stanat a historicion availabs. Availablre reviewedssociated chnts and literlagoon connd other imsing a weigpropriate refment TMDL
presented b
Os for a ration and/osin Plan, is
te of surfacdversely aff
st be mplementathat will resuairment of troach’. Theng the ceptable ndards. Ducal analysisle for e literature
d to understhanges in rature dition over
mpacts (Figught of evideference timL developmbelow is als
23
or
ce ffect
ion ult in the e
ue to s of
and tand
time ures nce
me ment so
Figure 8.
Figure 9.
Timeline of ur
Timeline of ur
rbanization an
rbanization an
nd lagoon tren
nd lagoon tren
nds (1800s thr
nds (mid 1970s
rough early 19
s through cur
970s)
rrent)
24
4.1 LaAs the fihistoricaand earlbegan adevelopaltered tconstrucnarrow lLagoon Californiexchangwere sigPlan releundevelPropulsi In 1966 2002); hagricultuMesa arexpressdevelopfollowingenvironsapproximincreasequality inincludingwatersh While debe the bperiod iswatershdeveloptopograpmost recmodified
and Use Cirst Mexicanally maintainly 1900s. B
acquiring pa, urban infrthe natural ction of U.Socation and(Mudie et aia State Pages (LPL Fognificant alteeased in 19oped (Duncion, 1971).
the Upper however, byural areas breas (City oed concernment alongg five yearss was expemately 1,00ed developmn the Lagoog agricultured ceased
evelopmentbeginning ofs illustrateded were noed based ophic maps fcent land usd based on
Changes in land granned as a faBy the earlyarcels of lanrastructure, drainage a
S. Highway d restrictedal., 1974). rks in histooundation aerations to 973 found tcan and Jo
Los Peñasqy 1975, the being conveof San Diegns associateg the shoress (1974 to 1cted to incr
00 people (Mment had aon (Jet Prore and graz(White and
t occurred sf intense wa in Figure 1
ot available on the locatfrom the 19se coveragthis inform
n the Losnt in Californamily homesy 1900s, thend surroundincluding cnd restricte101 in 1932 the tidal prThe North
orically tidal and the Stathe Lagoonhat the arenes, 1973)
quitos subwwatershed
erted to urbo, 2005). Ied with the s of the Lag979), the p
rease by a fMudie et al
already beepulsion Labing. In 198
d Greer, 200
sporadicallyatershed de10. Land usfor this perion and typ
970s (primae (from SAation in ord
s Peñasqunia, land instead and le City of Sading the Lagconstructioned the mout2 permanerism and exBeach Parkareas whic
ate Coastal n’s hydrologa surround, but was a
watershed w experience
ban uses, spn 1974, a Canticipated
goon. The population sfactor of fou., 1974). Un identifiedb, 1971); ho89, cattle gr02) primaril
y before theevelopmense/land covriod, therefope of structuarily the La ANDAG 200der to create
uitos Watethe Los Peivestock ra
an Diego angoon. As tn of the railrth of the Lantly confinexchange beking Lot wach further inConservangy, the Initiaing the Lagt the thresh
was 9% urbed significapecifically inCalifornia Fd completioreport also
surroundingur to six ov
Urban runoff as the primowever, othrazing in thely due to ve
e 1970s, tht. Land usever data forore, a histoures that arJolla quadr
00 – refer toe a uniform
ershed eñasquitos nch througnd San Dieghe region broad (1880
agoon. Lateed the inlet etween the as constructnfluenced hncy, 1985). al Coastline
goon remainhold of rapid
banized (Want urbanizan the Powa
Fish and Gaon of a 50 a
stated thatg the immeder the 1972f associatedmary threat her factors ee Los Peñaehicular con
e mid-1970e associater the Los Perical coverare shown inrangle – dao Section 3.
m historical l
watershed hout the 18go County
began to s-1925), er, the to a single,ocean and ted in 1968
hydrologic Although te Study andned relatived growth (J
White and Gration with ay and Miraame report cre t within the diate lagoo2 level of d with the to water
existed asquitos Crenflicts.
0s appears ed with this eñasquitosage was USGS
ated 1975). .1) was land use m
25
was 800s
,
8 by
there d ely Jet
reer,
a
n
eek
to time
The
ap
for the whistorica
Figure 10.
watershed fal time perio
Historic land
for comparisods are sho
d use in the Lo
son. Land own in Tabl
os Peñasquito
use differee 2.
os watershed
nces betwe
(1970’s)
een the currrent and
26
Table 2. C
Land Use
Agriculture
Commercia
Constructio
High Dens
Industrial/T
Open
Parks
Recreation
Single Fam
Water
Total
From 19Creek wLos PeñAdditionwatershValley Rwatershthe StateSorrento101 bridexchangsurround
Current (SAND
e
al
on/Transitional
ity Residential
Transportation
n
mily Residentia
966 to 1999watershed inñasquitos wnal highwayed to accom
Road (~196ed (Greer ae Route 56o Valley Rodge was conge. Figure ding roads
DAG 2000) vs.
Currenarea (a
7
3,5
1
1,8
11,6
25,4
1,3
6
l 14,2
1
59,8
9, the acreancreased by
watershed wy infrastructmmodate in6) and Carmand Stow, 2 overpass (
oad was connstructed o11 shows and highwa
historical lan
nt c)
Currenarea (%
741 1.2
591 6.0
169 0.2
840 3.0
654 19.4
463 42.5
326 2.2
670 1.1
258 23.8
161 0.2
879 100.0
age of urbany 290 perce
was dominaure was buncreasing pmel Valley 2003) as we(1995). Tonverted to aver the Lagthe major rays ultimate
d use compar
nt %)
Historarea (a
24%
00% 1,
28%
07%
46% 4,
52% 47,
22% 2,
12%
81% 5,
27%
00% 59,
nized land went (White a
ated by urbailt in and ar
population gRoad (1983ell as segm decrease ia bike pathgoon mouthroads withinely reaches
rison
ric ac)
Historarea (%
100 0.1
,088 1.8
23 0.0
648 1.0
,830 8.0
,445 79.2
,884 0.4
139 0.2
,155 8.6
160 0.2
,879 100.0
within the uand Greer, an uses (Ciround the Lgrowth. Re3) both imp
ments of theimpacts froin 2003 an
h in August n the waterss the Lagoo
ric %)
RelativChang
(%)
7% 1.0
2% 4.1
4% 0.2
8% 1.9
7% 11.4
3% -36.7
8% 1.7
3% 0.8
1% 15.2
7% 0.0
0%
upper Los P2002) and ty of San D
Los Peñasqealignment opacted the se I-5 freewaom road infrnd a new U.
2005, enhashed. Runo
on.
ve ge
07%
8%
24%
99%
40%
71%
73%
89%
20%
00%
Peñasquitosby 2000, th
Diego, 2005quitos of Sorrentosurroundingy (1994) anrastructure,.S. Highwayancing tidaloff from
27
s he 5).
o g nd y l
Figure 11.
To furthewere evregion3 ageneral populati
3 www.san
Major roads
er charactealuated. Pas shown intrends andon growth,
ndag.org
within the Lo
erize the lanopulation sn Figure 12 includes sresulting in
s Peñasquitos
nd use chansteadily incr2. This regiurrounding
n intense de
s watershed
nges, popureased fromonal popula areas. Geevelopment
lation trendm 1970 to 2ation analyeneral trendt throughou
ds in the Sa010 in the Ssis was useds show ex
ut the region
an Diego reSan Diego ed to evaluaxpansive n.
28
gion
ate
Figure 12.
4.1.1 LIn the paconnectrequiresdegradaoff lagoo101) aloconstrucsedimenurban ru1985). Hin the 19Lagoon.tidal prisrecentlyfreshwat
4.1.2 TMaintaincritical foparametof the mand outfwhereas
1,0
1,5
2,0
2,5
3,0
3,5
San Diego re
Los Peñasast 60 yearion to the o
s mechanicaation of the on channelsong the barrction of the nt from chaunoff and seHydromodif980s and 19 Water qua
sm, historic, hydromodter inputs.
Tidal Prismning a tidal or maintainters. The L
most importaflows of imps, wave-ind
000,000
500,000
000,000
500,000
000,000
500,000
1970
1972
egional popula
squitos Lars, the Lagoocean, to onal excavatiolagoon befos; (2) constrier beach tNorth Beacnging land ewage efflufication link990s playe
ality impactsal discharg
dification thaInformation
m Restrictprism, and ing adequa
Los Peñasqant problempounded wauced curre
1972
1974
1976
1978
San
ation trends (S
agoon Hisoon has evone that is clon to reopeore the 199truction of Nthat restrictch Parking uses upstre
uent (LPL Fked to urband (and still s to the Lage of wastewat has resun that relate
tion proper exc
ate salt marquitos Enhams occurringater from lants are res
1980
1982
1984
1986
Diego Reg
SANDAG, 201
storical Wolved from alosed to tida
en. The ma90s are: (1)North Torreed the locaLot in histoeam; and, (
Foundation n developmplays) a ma
goon are prwater efflueulted in increes to each o
change betwrsh salinity
ancement Pg in the Lagarge storm eponsible fo
1986
1988
1990
1992
gional Pop
0)
Water Quala tidal estual action fo
ajor factors ) the railroay Pines Ro
ation of the oric tidal are(5) decreasand State C
ment within ajor role inrimarily assent from 19eased sediof these im
ween the olevels, and
Plan identifiegoon (Elwanevents helpr the depos
1994
1996
1998
2000
ulation (SA
lity Conditary with anr long periothat were rd embankm
oad (part of lagoon moueas; (4) incsed water qCoastal Cothe watershthe degrad
sociated wit62-1972; amentation apacts is dis
cean and th other watees mouth cny, 2008). p to keep thsitional proc
2000
2002
2004
2006
ANDAG)
tions active
ods of timeresponsiblement that cu
U.S. Highwuth; (3) reased uality from nservancy,hed and lag
dation of theth a restrictnd more and year-roscussed be
he Lagoon,er quality losures as Tidal inflow
he mouth opcesses whic
2008
2010
29
and for uts way
goon e ed
ound low.
, is
one ws pen, ch
tend to c1985). Lagoon and floowatershdetermincomparamarine sportion o Despite continuonatural p(Mudie eacross tallows sand JonmechanLagoon refined ifrequencdredgingtidal flus
4.1.3 WTo accotreatmentributarieand medeffluent nutrientsproblemDiego M
4.1.4 W
Several the Lagoto 50 cm
4 (http://ww
close the laSedimentadeterminedding dynamed may incned that theable to the sources (Elof the Lago
the naturalously conneprocess witet al., 1974he lagoon rand to buildes, 1973). ically dredg(LPL Founn the mid 1cy of mouthg program cshing, wate
Wastewatemmodate int plants opes that ultimdian annuacaused inss (Bradshaw
ms continuedMetropolitan
Watershed
studies havoon. Mudie
m/100 years
ww.torreypine
agoon entraation of lagod that the vomics (Elwancrease the be grain sizedistributionwany, 2008
oon.
l process, hected to thethin the Los). For examreduced thed up at the In 1966, a
ging and redation and
1980s and eh closures. continues tor quality, an
er Effluentncreasing uperated frommately reacl discharge
sect and odow and Mudd until 1972
n sewer sys
d Sedimen
ve documee and Byrnes since Euro
e.org/parks/P
ance (LPL Foon environolume of sa
ny, 2008). Abuild-up rate distribution of grain siz8) rather tha
historical eve ocean unts Peñasquitmple, conste volume ofentrance aprogram wmoving theState Coas
early 1990s Because oo date (Elwnd marine h
t Dischargurban devem 1962-197h the Lagoo
e values andor problemsie, 1972), a
2 when surrstem.
ntation
ented the infe (1980) esopean settl
Peñasquitos-la
Foundation nments is a and trappedAlthough ine of sand bn of accumze on the ban watersh
vidence indtil at least 1tos watershtruction of tf water flow
and can prewas initiatede accumulatstal Consers to improveof continued
wany, 2008)habitats.
ge lopment wi72 and discon. Althoud assisted ws (Mudie etand depressrounding ar
flux of sedistimate that ement of th
agoon.html).
and State Cnatural pro
d in the inlencreased sebar formatioulated sand
beach, thus hed sources
icates that 888 and af
hed was accthe railroadwing in and vent tidal fl
d to restore ted sedimervancy, 198e tidal mixind, sporadic ). The prog
thin the wacharged efflgh these fawith maintat. al., 1974)sed salinityreas were a
ment originsedimenta
he area. Be
Coastal Coocess; reseet is a functediment loaon, this studd at the inleidentifying
s affecting t
the lagoon fter this timecelerated band U.S. Hout of the low altogeththe tidal prnt at the m
85). This efng and redumouth clos
gram seeks
atershed, twluent to the
acilities elevaining the tid), as well asy4 concentraall connecte
nating in theation rates hetween 196
onservancy,earch of theion of wave
ading from tdy also et was significant
the western
was e period, th
by disturbanHighway 10agoon; thisher (Duncarism by outh of the ffort was latuce the sures, a
s to enhance
wo wastewae Lagoon orvated minimdal prism, ts elevated ations. Theed to the Sa
e watershedhave increa68 and 1985
30
,
e the
n
he nces 01 s n
ter
e
ater r mum the
ese an
d to ased 5,
sedimenlagoon bwhich heThe maiCreek cuat the I-5located Valley pFoundatthe lagoThe moucoastal selevationyears, dConserv In an attwatershestablishdrain to by the Csignificadeterminmesas napproximunmitigarecentlyalteratiotributarie2005). The regilower prmonths depositsgraduallflushing,characte
nt from Carby 6.1 feet, elps retain in depositioulverts and5 culvert, wabout 1000ond behindtion and Staon has creauth of Carmsalt marsh n at the lowue to sedim
vancy, 1985
tempt to coed, the Reghed requirethe Lagoon
California Deant increasened that thenortheast ofmately 1,50ated urbaniz, the City ofns in hydroes of the La
ional climatrecipitation,(Williams, 1
s on the saly built-up o, which direeristics.
mel Valley convertingsediment (L
onal areas i at the sout
which is the 0’ west of I-d the berm aate Coastaated areas
mel Valley Coccupied th
wer end of tmentation fr5).
ntrol the incgional Boarements for cn in 1970 (Mepartment oe in flow of e runoff wasf the lagoon
00 gal/day (zation couldf San Diego
ology and magoon’s wa
te is charac and corres1997). Stot flats and w
over the yeaectly and ind
has raised salt marshLPL Foundn the lagoothern end ooutlet of C5 (removedand allow cl Conservaof higher e
Creek is thehe Carmel Vhe Carmel rom upstrea
creasing serd first apprcontrol of sMudie et al.of Fish andurban runos the resultn. During t(Mudie et ad double tho identified
modified geotershed, as
cterized by sponding hirm events twithin lagooars due to idirectly affe
the elevatioh vegetationation and S
on are just dof the Lagooarmel Valled in the latecoarse sedincy, 1985).
elevation whe primary exValley CreeValley culv
am (LPL Fo
edimentatioroved a resiltation from., 1974). D
d Game expff draining it of intensivhe fall of 19l.,1974). P
he annual sincreasing
omorphic cs a source o
higher precigh lagoon transport seon channelncreased sects lagoon
on of the non into ripariaState Coastdownstreamon near So
ey, was caue 1980s). Sment to be. Gradual shich tidal wxample of tek mouth; hverts rose 6oundation a
on rate fromolution (70-
m constructespite thes
pressed coninto the eas
ve residentia973, this rurestegaardediment loa urban devonditions wof sediment
cipitation dusalinity, duediment ints. These s
sediment loan functions a
ortheast coan and catttal Conservm of the I-5 orrento Valleused by a seStorm flows deposited sediment acater no longhis process
however, th6.1 feet in thand State C
m developm-R26). Thision projects
se actions, ancerns assostern channal developmnoff volume (1978) conad within 30elopment, r
within the thtation (City
uring winterring the dryo the lagoo
sediment deading and iand salt ma
orner of the tail marsh vancy, 1985
Carmel Vaey. Deposiewer berm from Carm(LPL ccumulationger reaches. In 1974, he ground he past 16
Coastal
ent in the s resolutions in areas tha 1974 repoociated withnel. It was ment of the e amountedncluded tha0 years. Mresulting in
hree main of San Die
r months any summer on which eposits havnadequate
arsh
31
5). alley ition
mel
n in s.
n hat ort h a
d to at ore
ego,
nd
ve
4.1.5 HContinueresulted2003; C1985). IsedimenencroacNationallocation Peñasqu(Figuresfrom eacfreshwatrelated tSection coastal sto more
Figure 13.
Habitat alteed sedimen in significaE, 2003; MIn 1985, thentation had chment of frl Wetland Inof different
uitos Lagoos 15 and 16ch study anter, and upto sediment3.4, Califorsalt marsh riparian ha
National Wet
erations ntation and ant alteratioudie et al, e Los Peñaremoved 2
reshwater wnventory (Nt wetland tyon Enhance6). Althoughnd time periland vegetat accumularnia State Phas been
abitat.
tland Inventor
freshwaterons to habita1974; LPL
asquitos Lag25 acres frowetlands anNWI) maps ypes is alsoement Planh there are iod, these mation types tion and im
Parks estimimpaired by
ry (NWI) - 1985
r inputs, boat (White aFoundationgoon Enha
om the coasnd reductionfrom 1985
o shown in m (1985) anddifferences
maps showin the east
mpediments mated that 1
y sedimenta
5
th resultingnd Greer, 2
n and State ncement P
stal salt man of saltwatand 2009 (maps that wd in the Mus in the dep
w an encroatern portionto tidal flow80 acres ofation, conv
g from urban2002; GreeCoastal Colan estimatrsh inventoter marsh is(Figures 13were includdie et al. 19
piction of wechment of r of the lago
w. As discuf the 390 toerting coas
nization, har and Stowonservancyted that ory. The s evident in
3 and 14). Ted in the L974 report etland areariparian, oon that is lussed in o 570 acresstal salt mar
32
ave we, y,
n the The os
as
ikely
s of rsh
Figure 14.
Figure 15.
National Wet
LPL Enhanc
tland Inventor
ement Plan –
ry (NWI) - 2009
1985 wetland
9
types
33
Figure 16.
4.2 ImRapid urand hydand flowyear-rouStow, 20urbanizashown thlandscapFurthermdegradapercent The contypicallysedimenincreasetiming ofincreasestreamb
Historical lag
mpacts of Urbanizationrologic cha
w velocities und flow in t003). In adation changhat impervipe and is dmore, imperation (USEPimpervious
ncerns assoy results in int loads in ues imperviof runoff eve
ed surface ebanks and w
goon wetland
Urbanizat of the wate
aracteristics(City of Sathe main tri
ddition to poges the landous surfaceirectly relatrvious cove
PA, 1999); wsness of the
ociated withncreased eurban areas
ousness, resents. Loweerosion andwashes sed
types (Mudie
ion on Waershed dires such as pen Diego, 20ibutaries toollutant loaddscape fromes represented to runofer has beenwith streame watershed
h urban deverosion ands (Burton asulting in alred infiltratid gullying. diment into
et al. 1974)
ater Qualiectly affectseak flow rat005). Incre the Lagoo
ding associm pervious nt the impriff (Burton an identified m degradatiod (Scheuler
velopment ad runoff ratend Pitt, 200lteration of ion rates spUltimately,surface wa
ty s the naturates, flow vo
eased develn (White anated with sto imperviont of land dnd Pitt, 200as the ‘unifon occurrinr, 1994).
are multifaces; account02). In addthe volume
peed surfacincreased
aters. Fresh
al drainage,olumes, flowlopment hand Greer, 2pecific land
ous. Recendevelopmen02; Scheulefying themeng with as li
ceted. Landing for up toition, urban
e, velocity, dce runoff wherosion dehwater runo
pollutant low durationsas resulted 2002; Greerd use practint research nt on the er, 1994). e’ in streamttle as ten
d developmo 50 percen
nization duration, anhich leads tstabilizes off from
34
oads s, in r and ices, has
ment nt of
nd to
adjacentfreshwatacreage Previousadditionurbanizaurbanizaclassifie25 perceperiod, tcfs, to 1indicate during thThis stuin minimfindings 17), whiThese aimpact tincrease
Figure 17.
0
50
100
150
200
250
300
Mon
thly
Mea
n Fl
ow (c
fs)
t and upstreter plant sp
e (CE, 2003
s studies wal informatiation. For eation within d as low urent), and 19the 1-2 yea,272 cubic increased
he period bdy also est
mum flows tare supporch demons
analyses illuhe Lagoon
ed sedimen
Hydrograph
0
0
0
0
0
0
0
1964
1966
1967
1968
eam urban pecies have3).
which focuseion on histoexample, Wthe upper
rbanization 988-2000 a
ar flood intefeet per sebaseflow, setween 197imated a fohroughout trted by a re
strates a steustrate the g
and assist nt delivery fr
for Los Peñas
1969
1971
1972
1973
1974
Los
developmee encroache
ed on the Lorical condit
White and GLos Peñasq(<15 perce
as high urbarval increascond in eacsuch that di73 to1987 tour percent the study e
ecent revieweady increageneral urbwith identif
rom the wa
squitos Creek
1974
1976
1977
1978
1979
1981
s Penasquito196
ent also reded upon the
agoon and tions and h
Greer (2002quitos Cree
ent), 1973-1anization (>sed from 22ch respectivischarges athan the eaincrease in
equivalent tow of flow daase in montbanization tfying a peri
atershed, wa
k
1981
1982
1983
1984
1986
os Creek (U64-2000 Mon
duces saline area, redu
the surrouhydrologic c) classified ek watershe1987 as mo>25%). Ac29 cubic feeve period. above 1.7 carlier periodn runoff sinco 17 percenata in Los Phly mean flrends throuod in time was not the p
1987
1988
1989
1991
1992
USGS Gage nthly Flow
ity, and braucing the sa
nding watechanges ass
three distined: 1965-19oderate urbcross the enet per secoFlow durat
cfs occurred (White andce 1972, wnt per year
Peñasquitosows since t
ughout the wwhen deveprimary con
1992
1993
1994
1996
1997
1998
11023340)
ackish and alt marsh
ershed provsociated winct periods 973 was anization (1
ntire time nd (cfs), to ion curves d more ofted Greer, 20ith an incre(2002). Th
s Creek (Figthe 1970s. watershed lopment, anncern.
1998
1999
35
vide ith of
15-
745
n 002). ease hese gure that nd
4.3 SeA numeruse andprovidesresult in the Lagosedimenconditionwas neestandardloading for TMD Several conditiondevelop
• Uininth
• Pth
• FPin(2w
• EcwhrethinimthimAac
election ofric sedimen lagoon con
s the link tothe attainm
oon and wantation impan upon whi
eded becauds and avarate or othe
DL developm
lines of evins in order ment. The
Urbanization the watersn the mid-19he watershe
Population he populatio
Flow data: RPeñasquitosndicate that2002) asso
watershed. Evaluation onditions h
watershed imabitat loss educed tidahe Lagoon ncreased sumpacted wahe city sewempacts andAvailable lite
dequately faused by th
f TMDL Nunt TMDL tarnditions usi
o the narratiment of WQatershed weacts were lich the num
use numericilable data er measurement.
idence wereto determinse lines of
on trends: Ashed (Secti970s. Landed beginnindata: Trenon of the SaReview of hs Creek andt flow has inciated thes
of Lagoonave been inmpacts andis primarily
al flushing, ainclude sedubstantiallyater quality er system,
d developmeerature indiflushed outhe railroad
umeric Target was esing a ‘weighve WQO fo
QS for the Lere evaluatekely minim
meric sedimec criteria arefor the Lag
e of natural
e considerene an approevidence in
A review ofion 4.1) indd use data ng in the mid analysis an Diego rehistorical std the concluncreased suse flow incre
n conditionnfluenced bd problems y associatedand year-rodiment delivy in the mid-
in the Lagomaking it dent-associacates that s of the systberm (and
arget stablished tht of evidenor sedimentagoon. Aved to help ial. This timent target loe not specifoon does nbackground
ed when evopriate refenclude:
f historical licates that shows a neid 1970s. of populatioegion has breamflow dusions drawubstantiallyeases with
ns (Section by several fassociated
d with long-ound freshwvery associ-1970s. Thoon until 19difficult to diated impactsediment dtem due to other phys
through thence’ approat and define
vailable dataidentify the
me period doad was cafied in Calif
not specificad sediment
valuating therence time
iterature thintensive d
early 37% d
on data (Sebeen steadidata from thwn by Whitey since the urbanizatio
4.1.1). As factors, whid with the la-term sedimwater input.ated with u
he wastewa972 when thifferentiate ts during theposition frproblems aical alterati
e historical aach. The nues the conda and literageneral timefines the r
alculated. Tfornia’s watally define at loading tha
e watershee period for
at describedevelopmendecrease in
ection 4.1) ily increasin
he USGS gae and Gree1970s. Wh
on trends in
described ich can be s
agoon moutmentation im. Watershe
urban develater treatmehe area wasbetween this time perirom the watat the lagooons) and se
analysis of umeric targditions that wture studies
me period wreference This approater quality a sedimentat can be u
ed and LagoTMDL
es urbanizant began in n open spac
indicates thng since 19age on Los
er (2002) hite and Gre the
above, Lagseparated ith. Salt mampacts, ed impacts topment, wh
ent plants s connecte
he wastewaiod (pre-19tershed is n
on mouth ediment bu
36
land get will s of
when
ach
t used
oon
tion the
ce in
hat 970. s
eer
goon into
arsh
to hich
d to ater 72). not
uild-
uredsplawmth
Consideachievincalculate(Figure land usedecreasSANDAGland useLagoon thresholimpervioperiod. The histusing threpresen
p at the oceeplaced andiscussed aediment burimarily a fu
argely sepawatershed. manage andhe sedimen
eration of thng WQS fored based o10). Existine category aed by nearG 2000 lane cover waswatershed d of stream
ousness (Sc
toric land use LSPC wants the sed
ean inlet. Nd have resubove, reduc
uild-up at thunction of l
arate from thThese fact
d improve cnt TMDL an
hese variousr sediment bon the historng and histoare shown rly 37% betwd use datas also deterwas appro
m degradatiocheuler, 19
se coveragatershed moiment TMD
Note that thulted in impctions in thee ocean inlittoral forcehe sedimentors are impconditions walysis.
s lines of evbefore the mric mid-197oric land usin Table 2.ween the m). The percrmined. Ov
oximately 9.on that occ
994), thereb
e was usedodel (see A
DL numeric
he Highwayproved tidale tidal prismlet. Sedime
es (Elwany, ntation probportant to uwithin the La
vidence indmid-1970s;
70s land usese areas an This table
mid-1970s acent impervverall, in the4% percen
curs at 10 toby further ju
d to calculaAppendix A)target.
y 101 bridge exchange m have resuent impacts2008) and
blems that onderstand agoon, but
dicates that therefore te distributiond the calcu indicates t
and existingvious assoce mid-1970
nt imperviouo 15 percenustifying use
te the sedim). This hist
e abutmentthrough theulted in incs at the oceother facto
originate froin order to are outside
t the Lagoothe numericon for the wulated percethat open sg conditionsciated with ts the Los P
us, which isnt of waterse of this his
ment load toric sedime
ts were recee area. As reased
ean inlet areors that are om the effectively e the scope
n was likelyc target wa
watershed ent changepace s (based onthe historic Peñasquitoss just belowshed storic time
to the Lagoent load
37
ently
e
e of
y s
e by
n
s w the
on
5 DaMultiple particularecently Data demeteoroinformatwatershsuspenddetails. 5.1 StAvailablcalibratiolong termDaily daparameta downs5.2). AdCanyon,(City of S18). Los Peñrecordeddata (20twice thoCanyon and Carcollectedvolume, the tenththe maspresente
ata Indata sourc
ar stream flocollected b
scribing theological datation and daed and Lag
ded sedime
reamflow e streamfloon and valim flow gage
ata from 199ters. Total stream USGdditional str, and CarmSan Diego,
ñasquitos Cd the highe007-2008) sose in CarmCreek. A c
rmel Creek d on Carrolflashy resp
h percentiles loading sed in Appen
nventoces were usow and watby watershee watersheda, and irrigata sondes a
goon modelent data; ref
Data Sumow data colldation. Thee (110233490 through suspended
GS sedimenreamflow da
mel Creeks a, 2009) as d
Creek drainsst measure
shows that mel Creek acontinual inindicated cl Canyon Cponse time,e. Additionstation (MLSndix A.
ory ansed to charater quality ced stakehold’s topograation needsanalyzing pls. This secfer to the M
mmary lected withie United St
40) in the up2008 were
d solids (TSnt monitorinata were coas part of thdescribed in
s the largesed flows andmedian flowand two ordncrease in cconsistent bCreek includ, and low ba
nal stream fS) and loca
nd Anacterize theconditions. lders to ass
aphy, land us along withpressure anction summ
Modeling Re
in the watertates Geolopper Los Pe downloade
SS) data weng station (3ollected at the Los Peñn the Mode
st area withd runoff volws in Los Pders of magcumulative baseflows. ded periodsaseflow. Lflow data, intion-specifi
nalysie watershed Much of th
sist with TMuse, soil chah available nd salinity wmarizes streeport (Appe
rshed wereogical Surveeñasquitos ed for calibrere also col325423117the base of ñasquitos Teling Report
in the watelume (Figur
Peñasquitosgnitude greavolume for By contras
s with little cow flows atncluding a dc challenge
s d and Lagohis informat
MDL model aracteristicsbathymetric
were used toeam flow anendix A) for
e compiled fey (USGS) watershed
ration of molected at th
7124501) (sLos Peñas
MDL monitt (Appendix
ershed and,re 19). Revs Creek weater than inLos Peñas
st, streamflochange in ct this stationdiscussion es to flow m
oon, in tion was developmes, c survey o calibrate
nd total additional
for model maintains
d (Figure 18odel hydrol
his location see Sectionsquitos, Caroring study
x A) (Figure
accordinglview of recere roughly Carroll
squitos Creow data cumulative n were withof data from
monitoring a
38
ent.
the
a 8). ogic and
n rroll
y e
ly, ent
ek
hin m are
Figure 18.
Monitoring loocations in thhe Los Peñasq
quitos watershhed
39
Figure 19.
5.2 SuTotal su(in accoPeñasqu18). The3254231water anthe confwere alsrequiremlocated wCarroll Cunderstapurpose Pollutogthroughoas part ostreams
0
1,000
2,000
3,000
4,000
5,000
6,000
7,000
9/
Cum
ulat
ive
Volu
me
(ac-
ft)
Cumulative f
uspended spended sordance withuitos waterse USGS col117124501nd dry weatfluence withso monitorements. In awithin the w
Canyon Creand the rela
es.
graph sampout a stormof the TMD flowing int
0
0
0
0
0
0
0
0
/14/2007
Ca
CaCr
LoCr
flow volumes
Sedimenolids and pah Regional shed and ullected sam (USGS, 20ther runoff wh Carroll Caed at this staaddition, twowatershed oeek (TWASationship be
ples charactm were colle
L monitorino the lagoo
11/3/2007
armel Creek
arroll Canyon reek
os Penasquitosreek
at TMDL mon
t Data Sumarticle size Board requ
used to devmples at gag009). Evenwere collecanyon Creeation since o Temporaron Los Peñ-1). Collecetween flow
terizing susected duringng study. Son: Los Peñ
7 12/23
s
nitoring locatio
mmary data were
uirements) aelop and cage 1102334nt mean concted at the Mek . Storm w
2001, in acry Watershe
ñasquitos Cctively, thesw and sedim
spended seg three storSamples weñasquitos, C
/2007 2
ons
collected bat several lalibrate the40 as well ancentrationMLS on Loswater and dccordance wed Assessm
Creek upstrese data werment loadin
diment conrms in the 2ere collectedCarroll Can
2/11/2008
by the City oocations w watershed
as at gage s (EMCs) fs Peñasquidry weathewith NPDEment Statioeam (TWASe used to bg for mode
ncentration 2007-2008 sd from the tyon, and C
4/1/200
of San Diegithin the Lo
d model (Fig
rom storm itos Creek nr runoff eve
ES permit ons (TWAS)S-2) and onbetter el developm
changes storm seasthree major
Carmel Cree
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.08
40
go os gure
near ents
) are n
ment
on r eks.
00
50
00
50
00
50
00
50
00
50
00
Rai
nfal
l (in
)
Longer-tTSS conmore thapossiblypresenc(Figure 2EMCs aand Carsize distwith rain
Figure 20.
1
10
1,00
10,00
TSS
(mg/
L)term datasencentrationsan five time
y due to thece of the El 20). Whent Carroll Ca
rmel Creekstribution, funfall are pre
EMC/Median
1
10
00
00
00
Carm
el C
reek
Pollut
11/30/2007
12/7/2007
2/3/2008
ets were alss recorded es lower thae presence o
Cuervo No comparing
anyon Crees (Figure 20rther comp
esented in A
n TSS and 95th
Carro
l Can
yon
Cree
k
tograph statio(3 storms)
//
so availableat the MLS
an the data of cattails u
orte wetlandg just the poek were con0). Additionarison of th
Appendix A
h percentile co
Los
Pena
squi
tos
Cree
k
USons
e for compaS on Los Pe
collected bupstream ofd diverting follutographnsistently hinal details ohe pollutogrA.
onfidence inte
1982
1985
-198
6
GS stationsUSG
S 325423117124501
USG
S 11023340
arison (MLSeñasquitos by the USGf the Los Peflows from Ls for the thigher than ton sedimenraphs and E
ervals for all s
MLS
(2
001-
2008
)
NPD
S and USGCreek sinc
GS at both señasquitosLos Peñasqree major sthose at Lont data, inclEMCs, and
sampling even
TWAS
-1
DES monitorin
11/30/2007
2/3/2008
GS stations)e 2001 wer
stations, MLS and tquitos Creestreams, TSos Peñasqu
uding particorrelation
nts
TWAS
-2
ng
41
). re
the ek SS itos cle
ns
6 SoThe purpsedimenpoint anpipes, otreatmenare reguNPDES various into surfoperatiopolicy (Wor daily allocatiocontribu 6.1 LaSourcesconditionsedimenweathercar washsedimenflows thafrom canassociatweather Sedimenhighly cofrom conleaving tcan cauimperviomaximuland useScouring
ourcepose of thent to the Losd nonpoint utfalls, andnt plants orulated throuregulationsorders. Noface watersons are reguWaiver Policload, which
ons for the Tte to Los P
and Use / Ss of sedimens; howevent downstrer loading is hing, sidewnt into receiat wash off nyon areas ted with wer watershed
nt sources worrelated wnstruction othe soil susse soil deta
ous areas, am amount fes, the amog of stream
e Asse source asss Peñasquisources. P conveyanc
r municipal ugh waste ds issued byonpoint sous. Some noulated undecy). The soh is then usTMDL. Theeñasquitos
Sediment nt are gene
er, storm eveam (especdominated
walk washiniving waterssediment tbelow stor
et weather cd loading.
were quantwith land useor agricultursceptible to achment ana different pfor each im
ount of sedim banks can
essmsessment isitos LagoonPoint sourcce channelsseparate st
discharge rey the State Wrces are dif
onpoint souer the Basinource assesed to separe following s Lagoon.
Source Cerally the savents can cially from cby nuisancg, and lawns. Wet weathat has burm water ouconditions,
tified by lane practicesral practiceserosion. W
nd further eprocess occ
mpervious lament that c
n also occur
ment s to identifyn. Sedimences typicallys from, for etorm sewerequirementWater Boarffuse sourcrces, such
n Plan’s wassment quarate the loasections di
Correlationame under ause signif
canyon areace flows fron over-irrigaather loadinilt up on lanutfalls. Dueemphasis w
nd use grou. For exams, disturbin
With the natrosion of thcurs where
and use typcan be transr in un-prot
y and quantnt can entey discharge example, mr systems (ts (WDRs) trd or the Re
ces that havas agricultu
aste discharantification iad allocationscuss the s
n both wet w
ficant erosioas below stom urban laation, whichng is dominnd surfacese to the highwas placed
up since sedmple, land d
g native vetive cover dhe land due sediment be. For bothsported is aected areas
tify the sour surface wat a specif
municipal waMS4s). Ththat implemegional Boave multiple ural and liverge requirems measuredns or wastesediment so
weather andon and tranorm water ond use actih pick up anated by ep
s during dryher runoff p on charact
diment loadisturbance
egetative codisturbed, ae to overlandbuilds up ovh pervious aa function os.
rces of waters from fic location astewater ese discha
ment federaard throughroutes of enestock ment waived as an anneload ources that
d dry weathnsport of outfalls). Dvities such nd transporisodic storm
y periods anpotential terizing wet
ding can bemay occur
over and a rainfall eved flow. Forver time to and imperv
of runoff.
42
both from
arges al h ntry
er nual
er
Dry as
rt m nd
t
e r
ent r a
vious
Since sewere gromodelinmonitoriuse contland use(e.g., higwhereasthe wate The sedmodel. sedimenconcent
6.2 PoStorm wCounty Ppermit foCaltransstorm wdescribethat are located wtherefore
6.2.1 PIn 1990,programMS4s orPhase I serving program
Approveto addremanagespecificaRunoff M
everal land ouped into g. Selectiong data antributions a
es. For exagh density rs other natuershed are
diment load Modeling p
nt loading arations are
oint Sourcwater runoff Phase I muor small mus. The permater is disc
ed below. Nenrolled in within areae, not spec
Phase I Mu the USEPA
m, designedr from beingof the progpopulations
m as a mean
ed urban ruess a varietyement, munally, large aManageme
use types ssimilar clas
on of these d literature
and critical sample, multresidential, ural categoropen space
contributedparameters and land use
highly dep
ces is regulate
unicipal sepunicipal discmitting procharged fromNPDES perthe statews controlled
cifically inclu
unicipal SA develope to preventg dischargegram requires of 100,00ns to contro
noff managy of water qicipally own
and mediumnt Plans tha
share hydrossifications,land use cavalues tha
sediment-cotiple urban clow density
ries were ge, low dens
d by each lavaried by lae type. Theendent on
ed through tparate stormchargers, acess definesm the end ormits are al
wide Generad by the Sauded in the
eparate Sed rules est harmful po
ed directly ied operato0 or more)
ol polluted d
gement proquality-relatned operati
m operatorsat address,
ologic or po resulting inategories wt could be uontributing categories y residentiarouped. Th
sity resident
and use typand use to
e amount ofland use.
the followinm sewer sysand the stats these discof a storm wso issued f
al Storm Waan Diego Co
TMDL ana
Storm Sewtablishing Pollutants fronto MS4s,rs of mediuto impleme
discharges
grams for mted issues, ions and ha
s are require at a minim
ollutant loadn a subset
was based oused to chapractices awere repre
al, and comhe three matial, and ind
pe was calcprovide thef runoff and
g NPDES pstem (MS4ewide stormcharges aswater convefor construcater permit ounty Phasalysis.
wer SystemPhase I of thom being waand then lo
um and largent an urbafrom MS4s
medium andincluding r
azardous wed to devel
mum, the fol
ding characof nine cateon the availaracterize inassociated wesented inde
mmercial/insajor land usdustrial/tran
culated usine correlatiod associated
permits: th) permit, thm water pes point sourceyance sysction and inprogram. T
se I MS4 pe
m (MS4) he NPDES ashed by uocal receivinge MS4s (thn runoff ma
s.
d large MS4roadway run
waste treatmop and impllowing elem
cteristics, megories for lability of ndividual lawith differeependently
stitutional), se sources nsportation.
ng the LSPCn between d sediment
e San Diege Phase II rmit issuedces becaustem, as dustrial siteThese sites
ermit and ar
storm waterban runoffng waters. hose generaanagement
4s are requnoff
ment. Moreplement Urbments:
43
many
and nt
y
in
C
t
go MS4 to se
es s are re,
er f into ally
uired
ban
• S• A• R• F• M• H• A• Il• R• C• P
Twenty CAS010(RegionwatershCity of P During wstorm wand assevents. dependesedimennatural pwatershcalculati All land sedimenis transpthat are that sevStorm WAdditionthese sit
Structural coAreas of sigRoadway ruFlood controMunicipally oHazardous wApplication olicit dischar
Regulation oConstructionPublic educa
one entities08758) and al Board, 2ed are San
Poway.
wet weatheater outfallsociated maThe amounent on the nnt to other aprocesses; ed so this rions.
uses were nt sources oported and attributed teral constru
Water Permnal informattes.
ontrol maintnificant devnoff manag
ol related toowned opewaste treatof pesticiderge detectioof sites clasn site and pation and o
s are identifare respon007). Resp
n Diego Cou
r events, sis. Sedimen
anagement nt of runoff nearby landareas of thehowever, m
resuspensio
classified aon these ladischargedto point souuction and it program ion would b
tenance; velopment ogement; o water quaerations sucment, stora
es, herbicideon and elimssified as aspost-construoutreach.
fied in Regnsible for adponsible Munty, the Ci
gnificant ernt also buildpractices aand associ
d manageme Lagoon camost of the on is assoc
as generatinnd use type
d to receivinurces are diindustrial sare located
be needed t
or redevelo
ality issues;ch as landfilage, or dispes and ferti
mination; ssociated wuction site r
ional Boardddressing wunicipal Disity of San D
rosion can ds up on theand is then wated conce
ment practican be caussediment i
ciated with a
ng point soes may be dng waters thischarged vites regulat
d within the to estimate
opment;
lls, wastewposal sites, ilizers;
with industrrunoff contr
d Order R9-water qualitschargers w
Diego, the C
occur alonge land surfawashed off
entrations aces. Note thed by both s contributeand quantif
urce loads diffuse in ohrough the via the MS4ted under thPhase 1 M
e the sedime
ater treatmetc.;
ial activity; rol; and
-2007-0001y concernswithin the LCity of Del M
g canyon wace from vaf the surfaceare, thereforhat the redianthropoge
ed by point fied in the M
because, arigin, the poMS4. Sed
4 from all lahe General
MS4 permittent load co
ent plants,
1 (NPDES Ns for the MSos Peñasq
Mar, and th
walls below arious source during rare, highly stribution oenic and sources in
MS4 load
although theollutant loadiment loads
and uses. N Statewide ed area.
ontribution f
44
etc.;
No. S4 uitos e
ces infall
of
the
e ding s Note
rom
6.2.2 In 1999,programin “urbanMS4 sysor operaassociatjurisdictiincludingor draina The GenOrder Nwater frothat discNPDES implemepollutantmust deschedule Non-tradtraditionand thatsystemsschools,and prispose signon-trad Entities quality csmall MS(SDUSD As with during radepende
Phase II M
the USEPAm, extendingnized areasstems are nated by the tion, or otheion over disg special diage district
neral Permo. 2003-00om “regulatcharges to apermit. The
ent a Stormts through tscribe the bes of imple
ditional Smal Small MSt pose signis serving pu, and other on and hos
gnificant waditional sma
that enroll concerns froS4s that ar
D) and othe
Phase I MSainfall evenent on the n
Municipal
A developeg the regulas” and consnot permitteUnited Sta
er public bosposal of seistricts unde, or similar
it for the Di05-DWQ (Sted Small Ma water of te General P
m Water Matheir MS4s best managmentation,
all MS4s mS4s includeificant wateublic campupublicly ow
spital compater quality all MS4s wh
in Order Noom their smre subject tors, as appli
S4s, pollutants. The amnearby land
Separate
ed rules estations to stostruction aced under thetes, a State
ody (createdewage, induer State lawentity.
scharge of Small MS4
MS4s.” A “rethe United SPermit requnagement Pto the Max
gement praand assign
may also reqe those locaer quality thuses (includwned learninlexes withinthreats. Th
hen adoptin
o. 2003-000mall MS4s. Io the Ordericable, in th
ants build umount of rund uses and
e Storm Se
tablishing Porm water d
ctivities that e municipae, city, townd by or pursustrial wastw such as a
Storm WatGeneral Pe
egulated SmStates or touires that SProgram (Sximum Exteactices (BMn responsib
quire coveraated within reats. In geding universng institution or adjacee State Wa
ng this Gen
05-DWQ arIn the San r include thehe watershe
p on land snoff and assmanageme
ewer Syst
Phase II of tdischarges disturb 1 tol Phase I re
n, borough, suant to States, storm wa sewer dist
ter from Smermit) regulmall MS4” io another Mmall MS4 D
SWMP) thatent PracticaPs), measu
bility of each
age by the or discharg
eneral, thessities, commons with camnt to other
ater Board ceral Permit
re responsibDiego Regie San Dieged.
surfaces ansociated coent practice
tem (MS4)
the NPDESfrom small o 5 acres oegulations, county, pa
ate law) hawater, or othtrict, flood c
mall MS4s, Wlates dischas defined a
MS4 regulatDischargerst reduces th
able (MEP).urable goalsh task.
permit. Thege to a permse are stormmunity collempuses), mregulated Mconsidered t.
ble for addrion, the nono Unified S
d then are oncentrationes.
)
S storm watMS4s loca
of land. Smaand are ow
arish, districaving her wastescontrol distr
Water Quaarges of sto
as a Small Med by an s develop ahe discharg The SWMs, include ti
e non-mitted MS4m water eges, primamilitary baseMS4s, or wdesignatin
ressing watn-traditiona
School Distr
washed offns are highl
45
ter ated all wned ct,
, rict
lity orm MS4
and ge of P ime
4,
ary es, hich g
ter al rict
f ly
6.2.3 Caltransmunicipa06-DWQdischargfacilitiesCaltranssystem. 6.3 NoA nonpoAdditionthe Lagoocean inreason, sedimenexisting interactithe openmore de
Caltrans s is regulateal storm wa
Q; CAS0000ges from Ca, and maint
s properties
onpoint Sooint source nally, storm oon; howevnlet was simwatershed
nt build-up amodel confon componn ocean boetailed discu
MS4s ed by a statater activitie003). The Caltrans proptenance ya
s and faciliti
ources is a sourcesurges and
ver, a recenmilar to bea
loading waat the inlet. figuration w
nents; thereundary immussion).
tewide stores and consCaltrans stoperties suchards. The sties eventua
e that dischad ocean tident study fouach sedimenas assumed Beach ero
which lacks efore, sedimmediately o
m water disstruction acorm water ph as the statorm water ally ends up
arges via ses can be and that accnt and tidal d to have a osion procewave, wav
ment modeliutside of th
scharge pectivities (Stapermit authoate highwaydischarges
p in either a
heet flow oa source of cumulated s
sources (Eless signifi
esses cannove-breakinging used a
he ocean inl
rmit that coate Board Oorizes stormy system, ps from mosta city or cou
or natural disediment t
sediment atElwany, 200cant contribot be mode
g, and wavereduced grlet (see Ap
overs all Order No. 9m water park and rid of these
unty storm d
scharges. to the moutt the Lagoo08). For thibution to eled with thee-current rid which sependix A fo
46
99-
e
drain
th of on’s is
e
ets or a
7 LiThe techsources analysissedimenWQOs oTMDL. The linkto represassociatwatershwater toregardin 7.1 MoIn selectcriteria wwatershinterest.followingthese coreceiving 7.2 TeTechniccritical insources
PhysicaRepresemodel seither threceivingconstituewaterboflow coninfluencestate inp
nkaghnical analyand the re
s. The purpnt loading thof the applic
age analyssent the phted watersheds based these load
ng model se
odel Selecting an appwere consided or receiv Regulatoryg discussioonsiderationg water con
echnical Cal criteria wn selecting and the nu
al Domain entation of telection. Th
he receivingg water. Seents and thdy dominat
nditions, a ses, quasi-sputs, but inc
e Anaysis of the rsponse of t
pose of the hat can be cable bene
sis for this Thysical proched. The mon rainfall e
dings. The felection and
ction Critepropriate apdered. Techving water y criteria incn details thns, approprnditions.
Criteria were dividedthe most a
umeric targe
the physicahe physicalg water itseelection of the conditionted by poinsteady-stateteady-statecludes diurn
alysisrelationshipthe waterbolinkage anareceived byficial uses.
TMDL is bascesses withodels provievents, andfollowing sed linkage an
eria pproach for hnical critercharacterisclude watee considerariate models
d into four mppropriate et associate
al domain is domain is lf or a combhe appropr
ns under wht source inpe approache simulationnal variabili
s p between pody to this lalysis is to y an impair This nume
sed on comin the impaide estimatid simulationections provnalyses.
TMDL calcria include tstics and prr quality obations in eas were cho
main topicsmodeling sed with the
s perhaps ththe focus obination of triate modelihich the waputs that ex is typically
n is typicallyity in hydro
pollutant loaoading is requantify theed waterboeric value is
mputer modaired receivion of sedimn of the resvide more d
culation, tecthe physicaocesses an
bjectives or ach of thesesen to simu
s. Considerasystem to ad
impaired w
he most imof the modethe contribuing domainterbody exhxhibits impay used. If thy performeddynamics a
ading from eferred to ae maximumody and stills represent
els that weing waterboment loadinsponse of thdetailed dis
chnical andal system, innd the consprocedural
e categorieulate waters
ation of eacddress the
waterbody.
portant coneling effort—uting water depends ohibits impaairments une system ind that assumassociated
identified as the linkag
m allowable l attain the ted by the
ere developeody and thengs from thehe receivingcussion
regulatory ncluding stituents of protocol. Ts. Based oshed and
ch topic watypes of
nsideration —typically, rshed and thon the irment. For
nder only loncludes tidames steadywith tidal
47
ge
ed e e g
The n
s
in
he
r a w-al y-
effects. on recei For watedriven flmodels or subsumodels conditionmodels for calib Source Primary Accuratein propescenario Water qsedimensources to develmajor soimpleme Critical The goawaterboto achievcontrols other comost vuin when the natudepositio ConstituAnother to be asmore sta
The steadyving water
erbodies affow and polconsider timurface, as wconsider mns immediarequire a suration purp
Contributipollutant s
ely represeerly represeos.
uality monint to the Lag
are watersop a sedimource categentation pur
Conditional of the TMdy and to idve WQOs. designed t
onditions. Tlnerability. sediments
ure of wet won.
uents important csessed. Chate variable
y-state and processes
ffected addilutant contrme-variablewell as a hy
monthly or seately beforeubstantial aoses.
ions ources musnting contrnting the sy
toring data goon, howe
shed runoff ment TMDL gories durinrposes.
ns MDL analysi
dentify poteThe critica
to protect whis is typicaFor the Lagare depos
weather eve
consideratihoice of staes included
quasi-steadduring a us
itionally or sributions, ae nonpoint sydrodynamieasonal va
e, during, anamount of in
st be considibutions froystem and
were not sever, availaand streamfor the Los
ng condition
s is to deteential allocal condition
water qualityally the perigoon and itsited at the m
ents that rep
on in modeate variables, the more d
dy-state moser-specifie
solely by no dynamic asource contc responseriability, whnd after indnformation
dered in theom nonpointultimately e
sufficient to able data inmbank eros
Peñasquitons consider
ermine the aation scenais the set oy will ensuriod of time s watershemouths of epresent the
el selection s is a criticadifficult the
odeling apped condition
onpoint souapproach is tributions fr
e of the recehile others edividual rain
regarding i
e model set sources aevaluating p
fully characdicate that ion. As a ros Lagoon ed controlla
assimilativerios that wif environme
re attainmenin which thd there is aeach creek. critical con
and applicaal part of mmodel will
proaches prn.
urces or prirecommen
rom a wateeiving wateenable assenfall events.input param
lection procand point sopotential loa
cterize all sthe main co
result, the mneed to ad
able for TM
e capacity oll enable thental condint of objecte waterbod
a high degre. This variandition for s
ation is theodel implembe to apply
rimarily foc
marily rainfnded. Dynarshed surfa
er. Some essment of . Dynamic
meters and
cess. ources is crad reductio
sources of ontrollable
models seledress the
MDL
of the hat waterbotions for whtives for all dy exhibits tee of variabbility is due
sediment
constituenmentation. y and calibr
48
us
fall-mic ace
f
data
ritical on
ected
dy hich
the bility e to
nt(s) The rate.
Howevesimulatedelicate applicab 7.3 ReA propecomponallocatioassuminestablishprotect tdevelop framewotarget anloading modelin 7.4 MoEstablisloading managecan be eassumptIdeally, tto assocof this seand rece
In additiwatershmay reqfactors. in ensuinor best mdevelopmodel s
The modessentiafirst com
er, if key stae all necess
balance mbility.
egulatory rly designeent of the T
on distributiong adherenches the benthose uses.a numeric
ork must ennd allow foranalysis ang framewor
odel Seleching the reis a critical
ement optioestablishedtions basedthe linkage ciate certainection is to eiving wate
on, to assised manage
quire future Such scenng monitorimanagemeed in subseelection.
deling systeal for accuramponent of t
ate variablesary aspectust be met
Criteria d and appl
TMDL and eon. The rece to WQOneficial use. In the castarget for T
nable directr the analysnd implemerk allow for
ction and lationship bcomponenns that will through a d on sound will be sup
n waterbodypresent ther response
st in TMDL ement, the mmodificatio
narios may ing efforts, nt practicesequent proj
em was divately modethe modelin
s are omittes of the sysbetween m
ied model penables accceiving wat
Os. For all ws for each wse of narratTMDL devet comparisosis of the duentation of r
the examin
Overviewbetween thet of TMDL dhelp achievnumber of scientific p
pported by my responsee approachs for TMDL
developmemodels can
ons to addreresult fromfuture imples (BMPs), oects. Ther
vided into twling hydrolong system i
ed from thestem and m
minimal con
provides thecurate asseter’s assimiwaters in thwaterbody tive objectiv
elopment (reon of modeluration of threquired rednation of gr
w e receiving developmeve the desitechniques
principles tomonitoring
es to flow anh taken to dL developm
ent and to pn be used toess specific the augmeementationor adaptatioefore, mod
wo componogy, hydrodis a watersh
e simulationmight producnstituent sim
e source-reessment of ilative capa
he San Diegto be prote
ves, interpreefer to Sectl results to those conditductions, it ross land us
water qualent. This allred source
s, ranging fro sophisticadata that and loading cevelop the ent in the L
provide deco simulate vc managementation of in of various on and linkael flexibility
ents represdynamics, ahed model
n, the modece unrealis
mulation and
esponse linassimilativ
acity is detego Region, ected and thetation is retion 4). Thethe selectetions. For tis also impse loading.
ity target anlows for theload reduc
rom qualitaated modelillow the TMconditions. linkage bet
Lagoon.
cision suppovarious sce
ment and eninput data tmanageme
age to addiy is a key at
sentative ofand water qthat predict
el might nottic results. d maximum
kage ve capacity ermined by the Basin P
he WQOs thequired to e modelingd numeric the watershortant that
nd source e evaluationctions. Thistive ng techniqu
MDL develo The objec
tween sour
ort for enarios andnvironmentato be collecent strategitional modettribute for
f the procesquality. Thets runoff an
49
t A
m
and
Plan hat
hed the
n of s
ues. oper ctive rces
d al cted ies els
sses e nd
externalhydrodypollutant The modTMDL MUSEPA modelinwith TMProgramand the hydrodyLSPC anReport
7.4.1 WLSPC whydrologand USEhydrologimpairedHydrologsimulatinsimplifiemodel hsorptiontemperanutrients The hydRain fallwithin a evaporathrough withdrawconsiderroutine iand inst The modsubwate
pollutant loynamic and t transport
dels selecteModeling To
and Tetra Tg tools, andDL develop
m in C++ (LSEnvironme
ynamic and nd EFDC m(Appendix
Watershed was selectedgic and hydEPA, 2002;gy and trand Lagoon. Lgic Simulatng hydrolog
ed stream faas been ex/desorption
ature simulas, and algae
drologic (wals and landswatershed
ation and plathe soil ma
wals/intakesrs three flown LSPC repream trans
del can simershed or la
oading as awater qualpatterns in
ed for the Loolbox (TooTech, Inc. (d databasepment and oSPC) is the
ental Fluids water qual
models are A).
Model: Lod for simuladraulic proce; USEPA, 2sport of sed
LSPC is a wtion Programgy, sedimenate and tranxpanded to n of selecteation, and the.
ater budget)s on variou. Varying sant matter eatrix. Theres. The landwpaths; surpresents thport, attach
mulate sedimand use are
a result of raity model ththe Lagoon
Lagoon sedolbox), whic(USEPA, 20s that haveother enviroe primary wDynamic City model insummarize
oading Simation of landesses that
2003). LSPdiments in twatershed mm Fortran (nt, and gennsport modinclude addd water quahe HSPF R
) process iss construct
soil types aexert a dem
e may also d representrface, interfe general d
hment when
ment loadineas). This is
ainfall evenhat simulaten.
iment TMDch was deve003). The
e been utilizonmental s
watershed hCode (EFDCn the Toolbed below an
mulation Prd-use baseaffect deliv
PC was spethe streamsmodeling sy(HSPF) (Bicneral water el. Since itditional GQality constit
RQUAL mod
s complex ated landscallow the wa
mand on thibe point sotation in theflow, and grdetachmentn there is n
gs from sps important
nts. The sees the com
DL are compeloped throToolbox is
zed over thetudies. Theydrology anC) is the recox modelin
nd describe
rogram in Cd sources o
very (Shen ecifically uses and stormystem that cknell et al.quality on lts original p
QUAL comptuents with dule for sim
and intercoapes, vegetater to infiltris rainfall. W
ource dischae LSPC moroundwatert of sedimeo rainfall, a
ecific sourct in terms o
econd compplex water
ponents of ough a joint a collectione past decae Loading Snd pollutanceiving watg package.d in detail i
C++ (LSPCof sedimentet al., 2004ed to simulam drains flowincludes st, 1997) algand, as we
public releaponents for
sediment, emulating diss
nnected wittation, and rate at diffeWater flowsarge and wdel environr outflow. T
ent due to raand scour.
ce areas (i.eof TMDL dev
ponent is a circulation
USEPA’s effort betw
n of modelsade to assisSimulation t loading mter . Both the n the Mode
C) t and the
4; Tetra Tecate watershwing to thereamlined orithms for
ell as a se, the LSP
enhanced solved oxyg
thin LSPC. bare soil arrent rates w
s overland awater nment The sedimeainfall, over
e., velopment
50
and
ween s, st
model
eling
ch hed
PC
gen,
reas while and
ent rland
and
allocatioand exisrequiredincorporbelow.
7.4.2 LThe Loswatershmodel insimulatinflow, sedincludingmodel wand coaUSEPA country.capabilittransporprocessphases, EFDC mstudies w The EFDquality mhydrodywater qucomputecomputephytoplaphosphosedimenthe settltoxics, athis projhydrodylagoon dsimulatesedimenare prov
on analysis.sting conditd load reducrated as an
Lagoon Mos Peñasquited model w
nput. EFDCng one-dimdiment trang rivers, lak
was originalstal applicaand has be In additionties, EFDC rt, near-fieldes, the tranand the tra
model has bworldwide b
DC model inmodel, (3) aynamic moduality portioe the transpes the fate oankton (threorus and silnt transport ing of susp
and bed loaect, the hyd
ynamics modriven by oced the transnt. Details ovided in Ham
. For this Tions within ctions from input to the
odel: Envitos Lagoon was linked tC is a public
mensional (1nsport, and kes, estuarily developeations (Hameen used exn to hydrodis capable
d and far-fiensport and fansport andbeen extensby universit
ncludes foua sediment del predicts on of the moport of the wof up to 22 ee groups),lica cycles, and toxics
pended sedd movemedrodynamic
odel simulatcean tides asport of sanof the EFDCmrick (1992
TMDL, the Lthe watersexisting co
e receiving
ronmentalwas simula
to EFDC anc domain, g1-D), two-dibiogeochemes, reservo
ed at the Vimrick, 1992)xtensively t
dynamic, saof simulati
eld dischargfate of toxicd fate of varsively testedties, govern
ur primary mtransport mwater dept
odel uses thwater qualitwater qual benthic algand fecal cmodules u
iment and tnt of noncocs and sedited the circand waters
nd, silt as noC model’s h2) and Tetra
LSPC modehed to esta
onditions. Twater mod
Fluid Dynated using tnd providedgeneral purimensional mical proceoirs, wetlandrginia Instit). This modto support Talinity, and tng cohesivge dilution fc contaminarious life stad, documennmental age
modules: (1model, and th, velocitiehe results fty variablesity parametgae, varioucoliform bacuse the hydtoxics, resu
ohesive sedment transulation, wat
shed inflowson-cohesivehydrodynama Tech (200
el was usedablish the TThe LSPC mdel for the L
namics Codthe EFDC m
d all freshwarpose mode(2-D), and
esses in suds, and coatute of Maridel is now bTMDL devetemperaturee and noncfrom multipants in the wages of finfnted, and aencies, and
1) a hydrody(4) a toxics
es, and watefrom the hyds. The wateters includins componecteria (Cercrodynamic
uspension odiments andport modelster temperas. The sede sedimentmic and eut02, 2006a,
d to calculaTMDL numemodel outpLagoon, as
de (EFDC) model. Theater flows aeling packagthree-dimerface waterastal regionne Sciencebeing suppoelopment the transport
cohesive seple sourceswater and sfish and sheapplied to ed other entit
ynamic mos model. Ther temperatdrodynamicer quality mng dissolve
ents of carbco and Colemodel resu
of bottom sed associates were useature, and siment transts, and claytrophication2006b, 200
te both histeric target aut was described
e LSPC and loadingge for
ensional (3-r systems ns. The EFe for estuarorted by the
hroughout thsimulation
ediment , eutrophicasediment ellfish. Thenvironmentties.
del, (2) a we ture. The c model to
model then ed oxygen, on, nitrogee 1994). Thults to calcuediments ad toxics. Fd. The salinity in thsport modely as cohesivn compone06c, 2006d
51
toric and
gs as
-D)
FDC ine e he
ation
e tal
water
n, he ulate nd
For
he l ve nts ).
The EFDthe Los water tefractionsmodeledcohesive
7.5 MoA complcalibratioEFDC mthe techdecision The modcharacteare baseTMDL navailableidentify arepresenloads thhistoricamodel swas idencapacitythe diffeexisting
DC model wPeñasquitomperature
s considered using the e sediment
odel Appllete discusson and vali
models is prnical analy
ns for the La
dels were inerize existined on theseumeric targe literature an approprnts the sedat met WQ
al period, a imulations wntified as thy for the lagrence betwconditions.
was configuos Lagoon fand salinity
ed in the monon-cohesmodule in
ication sion, includdation, androvided in thsis framewagoon and
nitially calibng conditione existing loget for sedimregarding uiate time peiment WQOOs and didhistoric lanwere perfo
he TMDL nugoon (i.e. thween the TM.
ured to simufor both exiy were bothodel includesive sedime
EFDC.
ing model cd water quahe Modelinork that wilits watersh
brated to obns in the waoads). In adment. As durbanizatioeriod (mid 1O. Conditio not advers
nd use covermed. Theumeric targe TMDL).
MDL load a
ulate hydroisting and hh modeled fe sand, silt,ent module
configuratioality calibratg Report (Al be used to
hed.
bserved hydatershed anddition, the
described inn trends an1970s) for cons presentsely impact erage for th resulting h
get and reprPercent rednd the sedi
dynamics ahistoric condfor hydrody and clay. and clay wa
on, hydrologtion and valAppendix Ao make reg
drologic andnd Lagoon models we
n Section 4nd Lagoon icalculating t at this timethe Lagoo
e watershehistorical neresents the ductions weiment load
and sedimeditions. Sp
ynamics. SSand and sas modeled
gic and hydlidation, of t
A). These mgulatory and
d water qua(required loere used to, a historicaimpacts wathe numerie were asson. To chara
ed was deveet annual se
loading (asere calculatthat corres
ent transporpecifically, ediment silt were d using the
drodynamicthe LSPC a
models provd managem
ality data tooad reductio establish a
al review ofas used to c target thaociated withacterize thieloped andediment loassimilative)ted based oponds with
52
rt in
c and vide
ment
o ons a f
at h s
ad ) on
8 IdRe
The calithe Los establishnonpoinmethodoand requcomponcritical c 8.1 LoThe caliLagoon,A). Usincompare 8.2 ApAs discuweight onumericsedimeninclude: condition 8.3 LoEstimatiLSPC msimulateprovidedwere simand sed 8.4 IdeDue to ttime perincludeson recor
entifieductbrated modPeñasquitohed. Point t sources wology used uired load rents are als
conditions, a
oading Anbrated LSP with the reg the EFDCed to the hi
pplicationussed in Seof evidence c target (i.e.ntation). Seurbanizatio
ns over tim
oad Estimaon of curre
model to preed watershed temporallymulated usiiment trans
entificatiohe higher trriod was ses the 1993 Erd over the
catiotions dels were uos Lagoon fsources we
were assignfor TMDL d
reductions fso discusseand a daily
alysis PC model weceiving waC model, thstorical num
of Numerection 4, the
approach t, a historicaeveral lineson trends, pe.
ation ent watersheedict flows aed processey variable long calibratesport (see A
on of Criticransport polected as thEl Nino storpast severa
n of L
sed to simufrom which ere then as
ned a load adevelopmefor the Los ed includingload expre
was used toater simulatehe assimilatmeric targe
ric Targete narrative Wto determinal period whs of evidencpopulation d
ed loading and pollutanes, based ooad estimaed, land useAppendix A
cal Conditotential of she critical prm events (al decades
Load A
ulate histornumeric ta
ssigned a wallocation (Lnt and the rPeñasquito
g the margiession.
estimate eed based otive capacitt for evalua
ts WQO for se
ne a referenhen the Lagce used to edata, flow d
to the impant concentron observedates for the e-specific p
A).
tions ediment du
period for as(10/1/92 – 4. Statistica
Alloc
ical and exargets and lwasteload aLA). This sresults in teos Lagoon.in of safety
existing sedon the EFDCty of the Lagation of sed
ediment wance conditiogoon was nestablish a data, and ev
aired Lagoorations. Thd rainfall dacritical peri
processes a
uring wet wessessment.4/30/93) is ally, 1993 c
ation
isting sedimoad reductllocation (W
section discerms of load Other TM(MOS), se
diment loadsC model (segoon was aiment quali
as interpreteon to definenot impairednumeric sevaluation of
on required e dynamic ata as modeod. These associated
eather, the . The wet sone of the w
corresponds
s and
ment loads ions were
WLA) while cusses the ding capac
MDL asonality a
s to the ee Appendassessed aity.
ed using a e the TMDLd for ediment targf Lagoon
use of the model-el input, load estimawith hydrol
1993 El Niseason thatwettest pers with the 9
53
d
to
ities
nd
ix nd
L
get
ates logy
ino t riods 93rd
percenti(Lindberthe Soutrainfall dpercentiannual r 8.5 CrFor TMDcomparireductiorepresentypicallypollutionthe TMDthrougho Due to tclosuresLagoon based o
8.6 CaLoad caand metTMDL wpoint sopermitteII MS4s,obtain Nloads esstreamb 8.7 MaA margindevelop(USEPAReservinof conse
le of annuargh Field). thern Califodata for the le year; merainfall than
ritical LocDL calculatison to the ns needed nts a conse
y display then impacts. DL analysisout a water
he variabilis, tidal fluctuarea was an achieving
alculation lculations fteorological
was divided urces ident
ees (San Di, and Caltra
NPDES requstimated webank erosio
argin of San of safety ing the rela
A, 1991). Thng a portionervative ass
al rainfall foSelection o
ornia CoastLos Angele
eaning 90 pn 1993 (Los
ations forion, a criticanumeric tarto meet the
ervative asse worst watAlthough, a, compliancrbody in ord
ty and dynauations, seassessed asg the nume
of TMDLsfor sedimenl conditionsamong poi
tified in the ego Countyans. The Uuirements fere solely thn and not o
afety (MOS) is in
ationship behe MOS can of the loasumptions i
r the past 1of this year tal Water Res Airport f
percent of ths Angeles W
r TMDL Caal location wrget in ordee WQOs. Tsessment oter quality ca critical locce with WQder to prote
amic naturediment fates the criticaric TMDL ta
s and Allont were devs from the cint sources Los Peñas
y and the cUSEPA’s pefor all stormhe result of other types
ncorporatedetween polln be incorpding capacn the mode
15 years mewas also c
Research Prfrom 1947 the years be
Water Board
alculationwithin the im
er to determThe selectio
of water quaconditions acation is use
QOs must bect beneficia
e of conditioe and transpal location. arget acros
ocation ofveloped usincritical wet p
as a WLA squitos wateities of San
ermitting regm water disc
watershedof point sou
d into a TMutant disch
porated in thcity provideseling and TM
easured at consistent wroject (SCCto 2000 shoetween 194d, 2002).
n mpaired wa
mine the reqon of a critiality conditioand are the ed for watee assessedal uses.
ons within tport, etc.), tLoad redu
ss the Lago
f Loads ng land useperiod (10/1and nonpoershed are
n Diego, Pogulations recharges frod runoff (lanurces.
DL to accoarges and he TMDL es an expliciMDL analys
the San Diwith studies CWRP). Anows that 1947 and 2000
aterbody is quired pollucal locationons, as themost vulne
er quality asd and maint
the Lagoonthe entire mctions for son.
e-based gen1/92 – 4/30
oint sourcesPhase I MS
oway, and Dequire munim MS4s. T
nd-use base
unt for uncewater qualiither explict MOS, whesis provides
ego Airport performed
n analysis o93 was the0 had less
selected fotant load
n (or locatiose areas erable to ssessment tained
(e.g., moumodeled sediment we
neration rat0/93). The s as a LA. TS4 co-
Del Mar), Phicipalities toThe existinged) and
ertainty in ty impacts itly or impliereas, the us an implici
54
t d by of e 90th
or
ons)
in
th
ere
tes
The
hase o g
citly. use it
MOS. Inare curre For this assumptassumpt
• C(1dds
• Splotrtrtwa
• Nadeac
• Ctaa
It was deassumptdevelop 8.8 SeThe fedevariationtwo gentranspormonitoriis recog
n either casently impair
TMDL, an tions througtions that w
Critical con10/1/92 – 4evelopmenecades. Bignificant h
Soil comporoportions
ocal parent ransport chransported wice as mund the rem
Numeric tarnd technicaevelopmenvidence’ annd lagoon ondition.
Critical locaarget acrospproach en
etermined ttions and thed for this s
easonalityeral regulatns. Sourceeral seasonrt mechanisng period, nized that d
e, the purpred will be
implicit MOghout TMD
were used.
ndition - Th/30/93) was
nt. This is oecause of tigher during
osition - Soof smaller psoils, becaaracteristicby surface ch clay as tainder assi
rget - The hal analysis nt of the numnalysis consimpacts ove
ation - TMDs the entirensures prote
that an exphe overall pstudy.
y tions at 40 s of sedimens in the Sasms can vathe greatesdry weathe
ose of the Mrestored, g
OS was incluDL developm
he wet seass selected
one of the wthe large amg this perio
oils that are particles siz
ause of diffecs. To acco
runoff werethe percentigned to the
historical anin order to meric sedimsidered all er time in o
DL load rede Lagoon (laection of be
plicit MOS wpredictive c
CFR 130.7ent are siman Diego rery betweenst transport r will contrib
MOS is to eiven the un
uded througment. The f
son that incas the critic
wettest perimount of ra
od than in ot
more easilzes (silt anderences in sount for these assumed tage of claye silt fractio
nalysis invoidentify an
ment targetavailable in
order to iden
ductions areagoon chaneneficial us
was not neeapability of
require thailar for both
egion). Desn the two se
of sedimenbute a dem
ensure thatncertainties
gh the applfollowing lis
cludes the 1cal conditioods on reco
ainfall, sedimther years w
ly transportd clay fractisettling ratese differencto be comp
y within eacon.
olved an exappropriate. This comnformation ntify a cons
e based on nnels and mes through
eded becauf the modeli
at TMDLs inh dry and wspite the simeasons. Thnt occurred
minimus disc
t the beneficin the TMD
lication of cst describes
993 El Ninn time perioord over thement loads with less ra
ted typicallyions), as coes and otheces in the mposed of 5 ch hydrolog
xtensive litee time perioprehensiveregarding u
servative re
meeting thmarsh areasout the lago
use of use oing framew
nclude seaswet weather milarity of whroughout th during raincharge of s
cial uses thDL analysis
conservatives several ke
o storm eveod for TMDe past sevewere
ainfall.
y have highompared to er sedimentmodel, soilspercent sa
gic soil grou
erature searod for e ‘weight of urbanizationeference
he numeric s). This oon. .
of conservaork that wa
sonal seasons (t
wet/dry sourhe TMDL nfall eventsediment;
55
hat .
e ey
ents DL eral
her
t s nd,
up,
rch
n
ative as
the rces,
. It
howeveras sedimcompletsedimen 8.9 DaThe loadexpressdelivery divided b(tons/mirolling avdelivery source crather, Eload allo
r, model cament transped for the 1
nt loading a
aily Load Ed allocationed in termsto streams
by the num2/day). EPverage perrates. In a
category thEPA expectocation for t
alibration anport is dram10/1/92 – 4/and associa
Expressions for the Las of net seds is highly v
mber of daysA expects tiod (e.g. 15
addition, EProughout thts the waterthat catego
nd TMDL dematically hig
/30/93 wet ated impacts
on agoon are piment loadariable on as in the critithe load all5-year), becPA does nothe watershershed averary.
evelopmenther during period to as to the Lag
presented ifor the criti
a daily and ical period (ocations tocause of thet expect eaed to necesage for the
t focused owet weatheccount for tgoon during
n Section 9ical period (annual bas
(211) to deo be evaluate natural va
ach square ssarily meeentire sour
on wet weater. Model sthe much gg this time p
9. Load allo(tons) becasis. Loads rive daily loted using aariability in mile within t the load arce categor
ther conditiosimulation wgreater period.
ocations areause sedime
were also oading ratesa long-termsediment a particula
allocation; ry to meet th
56
ons was
e ent
s
r
he
9 ToAl
The TMDwaterbosources provideson a maaccorda A TMDLand LA fmust incuncertaiwaterbo
A TMDL(Sectionsourcesportion omethodoTMDL. 9.1 Federal dischargincludescontribu Twenty CAS010(RegionPeñasquDel Marwithin Mcontriburegulate
otal MllocatDL is the tody while stthat cumul
s the basis ass loading nce with 40
L for a givenfor both noclude a marnty in the redy. Conce
L was estabn 6). The W. The LA pof loading rology, as de
Wasteloaregulations
ges regulates several Mtion from a
entities are08758) and al Board, 2uitos waters, and the C
MS4 boundation from P
ed under the
Maximtions otal amountill achievinglatively amoto establishbasis (e.g.
0 CFR 130.
n pollutant anpoint sourrgin of safeelationship ptually, this
TM
blished for tWLA portionportion is thereserved to escribed in
ad Allocatis (40 CFR 1ed under a S4 municipll discharge
e identified iare respon007). The shed are th
City of Powaaries were iPhase II MSe Caltrans M
mum D
t of pollutang the numeount to no mh water qua, net sedim.2(l).
and waterbrces and naty (MOS), ebetween p
s definition
MDL = ∑ W
he Lagoon n of this eque loading aaccount foSection 8.
ions 130.7) requdischarge
palities and ers in the w
in Regionalnsible for adPhase I MS
he County oay. Sedimencluded in
S4 facilities MS4 permit
Daily L
nt that can bric target. Amore than tality-based
ment amoun
body is comatural backgeither implic
pollutant loais represen
WLAs + ∑ LA
using the muation is theassigned to r any uncer An implicit
uire TMDLspermit. Theother perm
watershed is
l Board Ordddressing wS4 municipof San Diegent loads gthe WLA. within the wt. Permitte
Loads
be assimilaAllowable lthe TMDL mcontrols. Tt per year)
mprised of thground levecitly or explads and watnted by the
As + MOS
methodologe total loadinonpoint srtainty in tht MOS was
to include e Los Peña
mitted dischs presented
der R9-2007water qualital discharg
go, the City enerated frThe total Wwatershed aes enrolled
s and
ated by the oadings fromust be estTMDLs can or as a con
he WLA for els. In addilicitly, to acter quality iequation:
gy describeing assigneources. The data and
s incorporat
a WLA for asquitos waargers. The
d as the WL
7-0001 (NPy concerns
gers within tof San Die
rom land usWLA includeand highwa
d under the
receiving om pollutantablished; thbe express
ncentration
point sourcition, the TMcount for thn the receiv
ed above ed to point he MOS is t computatioted for this
point sourctershed e total sedimLA.
PDES No. s for the MSthe Los
ego, the Cityse activitieses the ay areas General
57
t his sed in
ces MDL he ving
the onal
ce
ment
S4
y of s
Statewidthe permtotal WLcontribuwith implocated 9.2 Accordinof the nouse contassignedboundar
9.3 The oveestablishperiod (2presenteuse conconditionthe numconditionwatershthe allowcurrent swithin ththe amofactors aand depreductiodeposit tsedimenanalysisdepositsperiods,during ththe totalfrom theis requir
de Construcmitted area LA. Additiontion from co
plementatioin the wate
Load Allong to federaonpoint soutributions tod to sedimery (ocean s
Summaryerall TMDL ahed by divid211 days). ed in Table ditions (fromns from the
meric target ns and the ed and Lag
wable load; sediment lo
he Lagoon aount of sediare importapositional prn in watersthroughout
nt from the s for historics in the Lag therefore, he critical w load reduc
e ocean boured for this s
ction and Inof the Phasnal informaonstructionn planning.rshed.
ocations al regulatiource or backo MS4 systent contribuediment co
y of TMDLand its comding the mo Current loa4. Existing
m the SANe critical wewas calculasame mete
goon respontherefore,
oads and hiare dependment that isnt componerocesses wshed sedime
the lagoonocean boun
cal conditiogoon origina
the TMDL wet period uction requireundary reprsource cate
ndustrial Stose 1 MS4 m
ation may b areas and. No other
ns (40 CFRkground loaems are inc
utions from ontributions
L Resultsmponent loaodeled loadads, historig loads werDAG 2000
et period (10ated basedeorological nse to the srequired lostoric (allow
dent on a nus transporteents in dete
within the Laent loading
n from oceandary undens indicatesates from tidresults sho
under histored from theresents nategory.
orm Watermunicipalitiee needed in industrial findividual N
R 130.2(g)),ading. For tcluded in thstorm surg).
ads are presds by the nucal loads, are estimateland use co
0/1/92 – 4/3 on modelindata in ordsame weathad reductiowable) loadumber of faed to the laermining thagoon. Theg affects theanic inputs (er current ans that a gredal inputs d
ow that a nerical landuse watershedural backgr
Permit proes and are,n the futurefacilities in tNPDES per
, load allocathe Los Peñhe WLAs deges and wav
sented in Tumber of daand required based onoverage) a30/93). As ng of historer to accurher conditioons represeds. Note thactors, inclugoon from e timing an
e Lagoon me amount of(considerinnd historicaeater propoduring loweet increase se conditiond is approxiround loads
gram are lo therefore,
e to help dethe watershrmits for po
ations are bñasquitos wescribed abve action a
Table 3. Daays within t
ed reductionn modeling nd meteorodescribed
rical (mid-19rately compons. Historent the diffeat sedimen
uding runoffthe watersh
nd magnitudmodel showsf sediment g a constan
al conditionrtion of sed
er watershedin oceanic
ns. To meeimately 67%s, therefore
ocated withincluded in
etermine thehed to assisint sources
best estimawatershed, bove. A LAlong the oc
aily loads arhe critical w
ns are of current l
ological in Section 4970s) land
pare the ric loads deerence betwnt dynamicsf volumes ahed. Thesede of erosios that a that can nt input of s). The mo
diment that d loading loads occu
et the TMDL%. Tidal inpe, no reduct
58
in n the e st s are
ates land was
cean
re wet
and
4, use
fine ween s and e on
odel
urs L, put tion
Table 3. T
TMDL WatershedOcean bouMOS Table 4. C
Sou
TMDL WatershedcontributionOcean bou(LA)
TMDL summarSource
d contribution (Wundary (LA)
Current vs. his
urce
d n (WLA) undary
ry
WLA)
storical loads Current Load
(tons) 13,663 7,719
5,944
Critical W
and percent rd Histor
(t12
9
Wet Period Loa12,360 2,580 9,780
Implicit
reduction rical Load tons) 2,360 2,580
9,780
ad (tons)
Load Red(tons1,305,13
+3,836 (inc
Daily
uction s)
P
3 9
crease)
Load (tons) 59 12 46
Implicit
Percent ReducRequired
10% 67%
+39% (increa
59
ction
ase)
10 RBicknell,HydrologEPA/600Researc
Bicknell,HydrologMountai
Burton, Amanage
BradshaPeñasquof Beach
Bradshalagoons
Cal. Fed
CaliforniRetrievehttp://wwPeñasqu
CaliforniPeñasquSeries #
CaliforniCAS000
CaliforniCAS 000
CaliforniCAS 000
CaliforniManage
Refere, B.R., J.C. gical Simul0/R-97/080ch Laborato
, B. R., J. Cgical simulan View, Ca
A., and R. ers, scientis
aw, 1968. Ruitos Lagoohes and Pa
aw, J. S., an. Calif. Mar
d. Bay-Delta
ia Coastal Ced August 8ww.coastalcuitos_Ex2.p
ia Departmuitos Lagoo
# 7 Californ
ia Regional0003. Gene
ia Regional0002. Gene
ia Regional0002. Gene
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ation Progr, U.S. Envi
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Pitt. 2002. Sts, and eng
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Conservanc8, 2009 fromconservancpdf
ent of Fish on: Recommia Wetlands
l Water Quaeral Permit O
l Water Quaeral Permit
l Water Quaeral Permit
rks. 2009. Tement.
s L. Kittle, Jr.,ram–FORTronmental , Georgia, 7
. L. Kittle, Jam - FORT3 pp.
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he biologicamarsh area
act No. 4-05
udie. 1972. mm. CalCOF
1992. Wa
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& Game, 1mendationss Informatio
ality ControOrder Caltr
ality ControOrder Indu
ality ControOrder Con
Torrey Pine
, A.S. DonigRAN, UserProtection A755 pp.
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al and ecoloa of the Tor5094-033.
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ater Quality
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ccbb/0406b
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ol Board. Onstruction.
es State Na
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rder No. 97
rder No. 99
atural Rese
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nts Fact Sh
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ard18H_Lo
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7-03-DWQ,
9-08-DQW;
erve, Vegeta
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r watershed
the Los erve. State
n Diego Co
heet.
Project Sum
s
Los astal Wetlan
NPDES No
NPDES No
NPDES No
ation
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os Lagoon n Foundatio
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os Angeles Reduce Ba
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os Watersh
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