JULY 201930% DESIGN PHASE
IMPROVING OUR COMMUNITIESwith Natural Drainage Systems (NDS)
What are they & why do we need them?When it rains in the Delridge and Westwood neighborhoods, pollution from our streets runs into Longfellow Creek untreated. This is not healthy for the creek or for people. The good news is: there is something we can do.
Natural Drainage Systems consist of shallow depressions in the public right-of-way, or “planter strip,” filled with deep-rooted plants and spongy soils that temporarily hold and clean polluted stormwater from streets and sidewalks. These features capture and clean pollutants before they can reach the creek.
Seattle Public Utilities (SPU) is planning to build natural drainage systems in your neighborhood in 2020-2021.
Community benefitsNatural Drainage Systems offer multiple benefits to local neighborhoods and ecosystems, including:
Greener, more attractive neighborhoods
Lower risk of flooding
Creation of habitat along our streets
Healthier creek ecosystems
Calmer traffic patterns
More street trees
What is the NDS Partnering Program?The 2016-2025 Natural Drainage Systems Partnering Program is a Seattle Public Utilities multi-year capital improvement program focused on Longfellow, Piper’s, and Thornton Creek watersheds.
The program’s goal is to construct street-side natural drainage systems that filter and manage stormwater and improve neighborhoods with street trees, traffic calming, and, in some cases, a limited number of sidewalks.
We are partnering with Seattle Department of Transportation (SDOT), Office of Arts & Culture 1% for the arts, and King County Flood Control District.
LONGFELLOW CREEK NDS PROJECT
JULY 201930% DESIGN PHASE
ELLIOTT BAY
DUWAM
ISH RIVER
PUGET SOUND/SALISH SEA
ROXHILLPARK
LONGFELLOW CREEK WATERSHED BOUNDARY
NOTES:-ALL BLUE SHADED AREAS FLOW INTO LONGFELLOW CREEK.-THE DASHED LINE OF LONGFELLOW CREEK INDICATES WHERE THE CREEK IS IN A PIPE.
SW BARTON ST
SW HENDERSON ST
SW TRENTON ST
SW CLOVERDALE ST
SW THISTLE ST
SW ROXBURY ST
24TH
AVE
SW
SW HOLDEN ST
SW KENYON ST
SW BRANDON ST
WEST SEATTLE BRIDGE
SW GENESEE ST
SW MORGAN ST
PROJECT AREA
LONGFELLOW CREEKLONGFELLOW CREEK WATERSHED BOUNDARY
LONGFELLOW CREEKWatershed Boundary
NOTES• All blue-shaded areas flow
into Longfellow Creek• The dashed line of
Longfellow Creek indicates where the creek is in a pipe
N
JULY 201930% DESIGN PHASE
2019 2020
OUTREACH FOR 30% DESIGNMID 2019
OUTREACH FOR 60% DESIGNLATE 2019 / EARLY 2020
30%DESIGN
REFINE PROJEC
T SCOPE
AND DEVELOP DES
IGN
CONSTRUCTIO
N
PRE-CONSTRUCTIONOUTREACHMID 2020
DRAFT POTE
NTIAL D
ESIG
N
FINALIZ
E + OBTA
IN PERMITS
60%DESIGN
SITING, FIELD INVESTIGATIONSSURVEY + CONCEPT DEVELOPMENT2017 to 2018
FINALDESIGN
60% INPUTS• Neighborhood priori�es• Local ecosystem needs• Detailed u�lity loca�ons + impacts• Plan�ng pale�es & new street trees• NDS sizing adjustments• Refinements to design dimensions + details• City right-of-way impacts• Balance of costs with budget• Maintenance of NDS• Permi�ng• Community concerns
FINAL INPUTS• Accessibility impacts• Contruc�on costs + impacts• Ongoing maintenance costs + responsibility• Permi�ng requirements• Construc�on ques�ons
We Are Here
A Healthier & Safer Longfellow Creek!
The Longfellow Creek Natural Drainage System (NDS) Project has completed preliminary planning and field inves�ga�ons.
At the 30% Design Phase we present poten�al street and drainage improvements to the community, answer ques�ons, and gather community concerns as we work toward finalizing the project scope based on regulatory requirements and project funding.
30% INPUTS• Neighborhood priori�es• Current drainage condi�ons• Loca�on of u�li�es• Local topography + mature trees• Rainfall runoff pa�erns along the street• Soil tes�ng + analysis• Loca�on of homes + paths• Loca�on of driveways• On-street parking pa�erns• City right-of-way impacts• Zoning code• Projected construc�on costs• Maintenance of NDS• Permi�ng• Community concerns
2021
WHERE WE ARE NOW...and where we’re going
JULY 201930% DESIGN PHASE
WHAT WE HEARDyou’d like to incorporate in NDS and path design
55513725242418141010106
Fix the path so it’s not so muddy
Add more lighting
Clean up litter and garbage
Improve visibility along the path
Replace the bridge
Plant new trees along the path
Make the path and bridge better for bikes, strollers, wheelchairs
Add places to sit
Slow traffic down along 24th Ave SW and SW Kenyon St
Other change (descriptions at right)
Add educational signs that explain importance of watershed
Remove the parking at the street end
0No change is necessary
• More police patrol• Add a trash can• Add street lights on SW Kenyon St• Add covered seating to bench• Double the amount of plants• Concerned about fast turnout at
24th and Kenyon cul-de-sac
24TH
AVE
SW
for SW Kenyon St at 24th Ave SW
JULY 201930% DESIGN PHASE
LONGFELLOW CREEK PATHLO
NG
FELL
OW
VIE
W LO
OKI
NG
EAS
TLO
NG
FELL
OW
VIE
W LO
OKI
NG
WES
T
JULY 201930% DESIGN PHASE
new accessible curb ramps
natural drainage system (nds)
improved path with pedestrian lighting
new sidewalk raised walkway with pedestrian lighting
key
section a-a (1”=4’)
city right-of-waycity right-of-way
right-of-way dedication
city
rig
ht-
of-
way
lon
gfe
llo
w
cree
k
long
fell
ow
cree
k
24th
ave
sw
sw kenyon st
exist. water main
potential path lighting(dependent on budget)
improvedpath natural drainage
system
underdrain
bicycle ramp
existing longfellow creek legacy trail marker
a
a’
b
c
bridge to be replaced
natural drainage system
city
rig
ht-
of-
way
city
rig
ht-
of-
way
potential nds and pathway improvementssw kenyon street and 24th ave sw
planting strip/lawn restoration
LONGFELLOW CREEK PATHPotential NDS and Pathway Improvements SW Kenyon St and 24th Ave SW
new accessible curb ramps
natural drainage system (nds)
improved pathnew sidewalk raised walkway
key
section a-a (1”=4’)
city right-of-waycity right-of-way
right-of-way dedication
city
rig
ht-
of-
way
lon
gfe
llo
w
cree
k
long
fell
ow
cree
k
24th
ave
sw
sw kenyon st
exist. water main
potential path lighting(dependent on budget)
improvedpath natural drainage
system
underdrain
bicycle ramp
existing longfellow creek legacy trail marker
a
a’
b
c
bridge to be replaced
natural drainage system
city
rig
ht-
of-
way
city
rig
ht-
of-
way
potential nds and pathway improvementssw kenyon street and 24th ave sw
planting strip/lawn restoration
new accessible curb ramps
natural drainage system (nds)
improved pathnew sidewalk raised walkway
key
section a-a (1”=4’)
city right-of-waycity right-of-way
right-of-way dedication
city
rig
ht-
of-
way
lon
gfe
llo
w
cree
k
long
fell
ow
cree
k
24th
ave
sw
sw kenyon st
exist. water main
potential path lighting(dependent on budget)
improvedpath natural drainage
system
underdrain
bicycle ramp
existing longfellow creek legacy trail marker
a
a’
b
c
bridge to be replaced
natural drainage system
city
rig
ht-
of-
way
city
rig
ht-
of-
way
potential nds and pathway improvementssw kenyon street and 24th ave sw
planting strip/lawn restoration
KEY
SECTION A-A’