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TRANSCRIPT
Hurricane Irene andlTropical Storm Lee
Hydraulic Engineering forHydraulic Engineering forNYSDOT Storm Response
Aug‐Sep 2011
S id L l B id C fStatewide Local Bridge Conference October 24, 2012
Wayne Gannett, P. E.NYSDOT Hydraulic Engineering Unit
Topicsp
• How much flooding did we get?• How much flooding did we get?
• Hydraulic engineering for NYSDOT post‐flood response
• Featured Watershed: Schoharie CreekFeatured Watershed: Schoharie Creek
How much flooding did we get?
Back to Back StormsHurricane Irene
8/28‐8/29Tropical Storm Lee
9/8‐9/9/ / 9/8‐9/9
Two storms affected the transportation psystem in 36 counties.
RainfallTotals forHurricaneIrene
NOAA Hydro meteorological y gPrediction Center
Hurricane Irene in NY
• Storm total rainfall 6‐8” across eastern NY; over 10” in Greene CountyCounty
• Major flooding: coastal flooding Long Island and NYC, Hudson Valley, western Catskills, Schoharie, Essex Co.
• New York State Thruway closed 130 milesNew York State Thruway closed 130 miles
• Widespread evacuations (over 5000) in Schoharie County
RainfallTotals forTropicalStormLeeLee
NOAA H dro meteorolo icalHydro meteorological Prediction Center
Tropical Storm Lee in NY
• Remnants of tropical storm Lee stalled over NY and PA, persisting over 48 hourspersisting over 48 hours
• Storm total rainfall 10‐12” west of Binghamton
• Major flooding in Susquehanna and Delaware River watersheds in NY and PA exceeding floods of 2006in NY and PA, exceeding floods of 2006
• 20,000 residents evacuated in Binghamton area
• Ground saturated from Hurricane Irene less than 2 weeks before exacerbated flooding in Catskills, Mohawk and Hudsonbefore exacerbated flooding in Catskills, Mohawk and Hudson Valley
USGS stream gages
• Irene: 55 new record flows (of 114 in NYS)• Lee: 5 new record flows
D.A.Peak Flow Previous Peak Q100
Hudson River at Green Island8,090 sm 180,000 cfs 215,000 cfs 188,000 cfs
Aug 29, 2011 Mar 1936Aug 29, 2011 Mar 1936
Schoharie Creek at Burtonsville886 128,000 81,600 78,100
Aug 28 2011 Jan 1996Aug 28, 2011 Jan 1996
Schoharie Creek at Prattsville237 120,000 +‐ 52,000 69,000
Aug 28, 2011 Jan 1996
Ausable River near Ausable Forks446 48,500 37,400 29,100
Aug 28, 2011 Jan 1996
Susquehanna River at Vestal3,941 129,000 119,000 108,0003,941 129,000 119,000 108,000
Sep 8, 2011 June 2006
Hydraulic Engineering for NYSDOT post‐flood response
Office of Structures ‐ Hydraulics Unit NYSDOT ff f fl dNYSDOT team effort for flood recoveryAt peak 181 road closures, 37 bridges (state + local)
Fi ld tField assessments
• Evaluation of closed bridges: I‐88, Rt. 7 & Rt. 20 overEvaluation of closed bridges: I 88, Rt. 7 & Rt. 20 over Schoharie Creek
• Stream erosion anddebris assessmentsin Schoharie Co. with NYSDEC
Office of Structures ‐ Hydraulics Unit
Field assessments (continued)
• Emergency repairs at Fox Creek/Rt. 443
• 43 bridges inEssex & Greene Co for stream channel and bridge protectionwork
Office of Structures ‐ Hydraulics Unit
Bridge Hydraulic Design
• Structures in‐house design: Kaaterskill Creek, Ramapo River, Brandow Creek at Batavia Kill.
• Design‐build: Rt. 42over West Kill (2)over West Kill (2)
• Bridge approaches:Bridge approaches:Wappassenning Creekand Mohawk River
Field assessmentsI 88 over Schoharie Creek Central BridgeI‐88 over Schoharie Creek, Central Bridge BIN 1070621 3 span , 210 ft. max span 1981
Flood impact:Bridge closureBridge closure
Post‐flood response: Bridge damage assessments and probe for scour holesDebris removal and re‐open bridges.
I‐88 over Schoharie Creek
Mon Aug 29, 2011closed pendingclosed pending scour investigation
( t d b i i )(note debris on pier)
W d A t 31Wed August 31scour probe pier
Field assessments43 b id R i 1 G Alb E C43 bridges ‐ Region 1 Greene, Albany, Essex Co.
Example: pRt. 296 over East Kill, Windham BIN 1045150 100 ft. span truss 1932
Rt. 296 over East Kill, Windham• Abutments on spread footings, no piles
Post Flood:Stone fill washed out Sheet piling peeled back 9 + ft. scour
Recommend:substructure inspectionsubstructure inspectiongravel bar removalvanes/weirs and armoring
Structure Hydraulic Design
Rt. 42 over West Kill (south)BIN 1025190 60 ft span thru girder 1928BIN 1025190 60 ft span thru girder 1928
Rt. 42 over West Kill (south)S 14 2011Sep 14, 2011
Abutment failureAbutment failureBridge overtopped
Temporary bridgeunder construction
Rt. 42 over West Kill (south)
New bridge:Integral abutments on piles100 ft spanDesign:
f20 ft scour14 ft/sec
Rt. 42 over West Kill (north)BIN 1025200 120 ft span truss 1928
Rt. 42 over West Kill (north)
north abutment
150 ft approach gone
Rt. 42 over West Kill (north)
New bridge:Integral abutments on piles150 ft spanDesign:
f17 ft scour7 ft/sec
DesignBuildContract
Rt. 282 over Wappasening Creek, Tioga Co.BIN 10908900 284 ft three span 1964
Flood impact:D b i l dDebris pluggedbridge spans.250 ft. of northroad approach washed out
P t fl d Fi ld l ti i t R9Post‐flood response: Field evaluation, assist R9 on emergency repair scope, bank and slope protection, bridge scour countermeasures. Unstable upstream g pbanks still exist upstream..
Pre‐floodL ki thLooking north
S Sep 15, 2011at northat northabutment
Pre-flood Upstream face
Sep 15, 2011Debris
UpstreamUpstreambank ‐ before
Reconstructingarmored slope Oct 2011
dNote: eroding high bank
Rt. 103 over Mohawk River at NYS Barge Canal Lock 9, Schenectady County BIN 40362501914 795 ft – 3 truss main spans 3 approach spans1914 795 ft 3 truss main spans, 3 approach spans
Rt. 103 over Mohawk River
Flood impactDebris jammedgates at Lock 9 damgates at Lock 9 dam.River washed out Rt.103 and park. Newchannel threatenedstability of Rt. 5
Post‐flood response: Damage assessments , reconstruct Rt. 103. Coordination with Canal Corp.reconstruct Rt. 103. Coordination with Canal Corp.
Lock 9Sep 7 2012Sep 7, 2012
Rt 103 bridge
Lock 9 and Rt 103
looking upstream
Looking north at Rt. 5
After the flood: debris at Lock 9 dam
North abutmentNorth abutmentwith concrete slope pavingslope paving
…and without .
Why we use piles
Reconstruction October 2011• Restore dam gates to operating conditionRestore dam gates to operating condition• Temporary causeway and dewater channel• Rebuild 400 ft. approach roadB id OK• Bridge OK
Featured Watershed: Schoharie Creek
Schoharie Creek
• Mohawk word meaning “Floating driftwood”
• 927 sq. mi.
• Flows north 93 miles Catskills to Mohawk
Schoharie Creek at Mohawk River, Sep 2011 Times Union
I 90 Thruway bridgeI‐90 Thruway bridge
Burtonsville USGSBurtonsville USGS
Blenheim covered bridgeBlenheim Gilboa Pumped storagePumped storage
Gilboa ReservoirPrattsville USGSPrattsville USGS
Schoharie CreekI 90 NYS Th B idI‐90 NYS Thruway Bridge
Schoharie CreekI‐90 NYS Thruway Bridgey g
1987 pier settlement from scour led to bridge collapse spread footings on compact glacial till – no pilesl d d b id i i dled to mandatory bridge inspection program and
national engineering focus on bridge scour Notable Schoharie Creek floods:
1955 73,600 cfs1987 72,2001996 80 2001996 80,200
Scour hole at New land pierJan 1996
Schoharie CreekBlenheim Covered BridgeBlenheim Covered Bridge
210 ft spanbuilt 1855
after Irene Sep 2011
Schoharie CreekBlenheim – Gilboa Pumped Storage Project
• lower reservoir has 40 ft. operating range• Embankment dam with non‐overflow spillway el. 910• Max outlet capacity• Max. outlet capacity
165,000 cfs el. 908.5 via 3 taintor gates
NYPA
Schoharie CreekBlenheim – Gilboa Pumped Storage ProjectO ti A 28 2011Operations on Aug 28, 2011
• 11:00 AM inflow < 20,000 cfs. lower reservoir el 865lower reservoir el 865
• 1:20 PM peak inflow 129,135 cfs All 3 taintor gates open; all 4 pumps on
• 3:20 PM peak outflow 118,614 cfs p ,lower reservoir el 898.2
raised 33 ft in 4 hoursNYPA
Schoharie CreekSchoharie Reservoir Gilboa Dam
• 17.6 billion gal
• 1326 ft. long x160 ft high concrete overflow spill way
• Emergency repairs done for sliding stability: rock anchors, siphons, crest notch (post 1996 flood)
• Current project: low level outlet, dam crest gates
Schoharie CreekSchoharie Reservoir Gilboa DamSchoharie Reservoir Gilboa Dam
Sun Aug 28, 2011Reservoir rose 20 ft in 9 hr
Peak flow 111,000 cfs8 ft flow over spillway
Mon Aug 29Mon Aug 29
NYCDEP
Schoharie CreekUpper watershedUpper watershed• Rain greater than 1 in./hr for 12+ hours• Batavia Kill, East Kill, West Kill Schoharie Creek
Schoharie CreekUSGS G P illUSGS Gage at Prattsville Q100 69,000 cfs
120,000 cfs August 28, 2011 Irene (indirect calcs)23,400 cfs September 7 Lee
Schoharie CreekUpper watershed – Rt 42 Lexington BIN 1025220Upper watershed Rt. 42, Lexington BIN 1025220
USGS – Aug 28, 2011
Schoharie CreekUpper watershed – Batavia Creek WindhamUpper watershed Batavia Creek, Windham
Albany Times Union – Aug 28
What did we learn from Irene and Lee?
E t bi fl d ft• Expect bigger floods, more often
• Good design practice:il f d ipile foundations
stone slope protectioninspect and maintain
• Woody debris and sediment during floods create major headaches at bridge openings
• Regular sediment removal needed where stream cannot be stabilized
What did we learn from Irene and Lee?
Expect bigger floods, more often. p gg ,
• 2011 floods of record ‐ add to1996 and 2006recent “floods of record”
• Northeast Regional Climate Center ‐ small increase in overall precipitation in NY; greater number of extreme rainfall events
E i f ll 100 (1956 1979) i l 66• Extreme rainfall events: 100 year event (1956‐1979) now equivalent to 66 year event (1980‐2009)
What did we learn from Irene and Lee?
Good design practice:Good design practice: • structures must have pile foundations• adequate hydraulic opening• embankments need stone slope protection• inspect and• inspect and
maintain
BIN 4036250Rt 103 over Mohawk River
What did we learn from Irene and Lee?
• Steep, forested watersheds in New York supply huge amounts of woody debris and sedimentamounts of woody debris and sediment…
What did we learn from Irene and Lee?
• which settle and blocks bridge openings• ….which settle and blocks bridge openings • ….and requires periodic sediment removal
BIN 1034960BIN 1034960Rt 96 over Catatonk Creek
Learning Assessment
Question 1:
How many USGS stream gages in NYS set new records with Hurricane Irene? A) 22
B) 31
C) 55
Learning Assessment
Question 1:How many USGS stream gages in NYS set new records with Hurricane Irene? A) 22
B) 31B) 31C) 55
Answer:55 gages throughout eastern NY55 gages throughout eastern NY
Learning Assessmentg
Question 2:QHighway failure at Rt. 282 over Wappasening Creek during Tropical Storm Lee was caused bby:
A) seepage through embankmentB) d b i bl k d dj t b idB) debris blocked adjacent bridge
openingC) poor sub base compactionC) poor sub base compaction
Learning Assessment
Question 2:Highway failure at Rt. 282 over Wappasening g ay a u e at t. 8 o e appase gCreek during Tropical Storm Lee was caused by:
A) seepage through embankmentA) seepage through embankmentB) debris blocked adjacent bridge
openingC) poor sub base compaction
AAnswer:debris blocked bridge opening, causing stream to overflowcausing stream to overflow
Learning Assessment
Question 3:
Current research suggest what trend isCurrent research suggest what trend is happening to precipitation in NYS?
A) much higher annual precipitationA) much higher annual precipitation
B) greater number of extreme rainfall events
C) more frequent rain on weekends
Learning Assessment
Question 3:
Current research suggest what trend isCurrent research suggest what trend is happening to precipitation in NYS?
A) much higher annual precipitationA) much higher annual precipitation
B) greater number of extreme rainfall events
C) more frequent rain on weekends
Answer:
greater number of extremegreater number of extreme rainfall events
Questions?Questions?
Hydraulic Engineering Unit
NYSDOT Office of StructuresNYSDOT Office of Structures
Th kThank you