preparing for sea level rise in san francisco bay bc3 june 17, 2011 jeremy lowe, esa pwa

PREPARING FOR SEA LEVEL RISEIN SAN FRANCISCO BAY

BC3June 17, 2011

Jeremy Lowe, ESA PWA

Mitigation - avoiding the unmanageable

Adaptation - managing the unavoidable

1890 1910 1930 1950 1970 1990 2010 2030 2050 2070 2090-20.0

-10.0

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

14

40

47

55

25

7

19

58

Sea Level Rise - USACE (2009) Circular 1155-2-211OPC Resolution March 11, 2011

Presidio Observed Presidio 19yr Mov Avg USACE Curve III USACE Curve IUSACE Historic OPC High OPC Medium OPC Low

Year

Sea

Leve

l Rise

Rel

ative

to 2

000,

in

2000 - 0 in2050 14 in2100 55 in2100+ ?? in

6.5ft NAVD - King Tide, January 20115.9ft NAVD – MHHW0.6ft increase ~ 2010 - 2030

Photo: Mark Songey, 02/17/11

Photo: Heidi Nutters, 11:30am, 02/17/11

Frank’s Dump West - New Year’s Eve 20058.9 ft tides; 40mph westerly winds Photo: Mark Taylor

Inundation

Erosion

Hayward Marsh - New Year’s Eve 20058.9 ft tides; 40mph westerly winds Photo: Mark Taylor

Functions

Urban Habitat Storm drainage Land fill Wastewater Utility corridors Trails

Storm drainage Designed for a certain bay elevation

Lack of drainage as MLLW rises Structures fixed relative to tide frame Upstream impacts will increase

Exposure increaseswith time

Adaptation mayrequire pumping

Opportunity toconsolidate

Functions

Urban Habitat Storm drainage Land fill Sewage treatment Utility corridors Trails

PGE

EBDA line

RailroadCable

HP Gas

Bay trail

Hold the Line

Realign

Rapid landward movement increases as sea level rises

Terraced Levee

Rapid landward movement increases as sea level rises

Mudflat Tidal Marsh Brackish MarshFreshwater

Swale

Treated Wastewater and Stormwater

Seepage

Overflow

Wave Attenuation

0ft 1ft 2ft 3ft 4ft

Existing levees

Terraced levees

Realign functions

Terraced levees

Enhance existing wetlands, realign levees

Lead Time Effective

Realign functions

Threshold

5ft

Decision

An Adaptation Strategy?

San Pedro Road, China Camp - January 2010 spring tidePhoto: Peter

Baye

Not an Adaptation Strategy