CEE 231 – Stanford University November 17, 2009

1. CEE 231 – Stanford University November 17, 2009 Planning for Future Sea Level Rise in the Corps of Engineers Thomas R. Kendall, USACE San Francisco District

2. Global Climate Change: What do we know? • The world is changing • Changes can be abrupt ~8°C change in 10 yrs Climate changes in central Greenland over the last 17,000 years show a large and rapid shift out of the ice age about 15,000 years ago, an irregular cooling into the Younger Dryas event, and an abrupt shift out of the event (a warming of about 8° C in a decade) toward modern values. from NRC (2002) Abrupt Climate Change: Inevitable Surprises

3. Climate Change & the Corps • The entire portfolio of Corps Civil Works water resources infrastructure and programs, including regulatory program, is potentially affected • ~ 12 million acres of land and water resources • ~ $2T infrastructure • >600 dams, >1000 coastal structures, >250 locks, >300 major seaports, >600 smaller harbors • 2nd largest number of recreational users • 75 major hydropower projects, (>20.72 GW, ~24% of US hydropower)

4. Climate Changerecent sea-level trends Sea-level measurements from 23 long tide gauge records in geologically stable environments show a rise of approximately 18 centimeters per century (~ 1.8 mm/year). Source: IPCC 2007

5. Sea-Level Change • Interagency team • Internal and external reviews • Provides technical background • Use multiple scenario approach • Engineer Circular 1165-2-211, 1 July 09 plan for uncertainty IPCC 2007 AR4 WG2 Figure 6.1. Climate change and the coastal system showing the major climate change factors, including external marine and terrestrial influences.

6. Sea Level Change Scenarios • High: modified (updated) NRC 1987 curve III • Intermediate: modified (updated) NRC 1987 curve I and IPCC • Low: extrapolation of historic trend • Key is to ask When is this likely to occur (i.e., look across the curves) Note: IPCC 2007 does not provide intermediate data points, high and low SRES scenarios shown for reference to intermediate (modified) curve I

7. NRC Update Opportunity • CA/OR/WA/USGS/NOAA/COE funding an NRC update next year that can become new NRC source for guidance (more current than 1987 NRC source) • CA EXECUTIVE ORDER S-13-08 (11/14/2008) The California Resources Agency… shall request that the National Academy of Sciences (NAS) convene an independent panel to complete the first California Sea Level Rise Assessment Report and initiate,… an independent sea level rise science and policy committee made up of state, national and international experts. • 2009 scope: provide values or a range of values of global sea level rise for the years 2030, 2050, and 2100; and evaluate the uncertainties associated with these values for each timeframe.

8. Guidance on Sea Level Change: Multiple Scenario Approach • Philosophy: • We can’t predict the future without uncertainty • Be prepared to implement flexible planning and engineering adaptations accounting for a range of possible changes • Must be able to recognize meaningful changes that may require additional response • Scenario predictions are based on fundamentally different assumptions about the processes • Inappropriate to combine different scenarios into a single prediction, then calculate an error distribution about it • Scenarios should not be considered better or worse, must develop alternatives for each • Different alternative plans can be evaluated as being better or worse than others for the range of future scenarios • Consider and seek to minimize the risk associated with multiple sea-level rise scenarios • Team set up to develop guidance (COE, NOAA, CSO,..change the Planning Guidance Notebook) • P&G (Fed Planning Principles & Guidelines) update should address multiple scenarios

9. Corps of Engineers Policystep-by-step approach

10. Planning Horizon

11. EC Steps 16-18

12. EC Steps 16-18 • These steps are a function of a Principles & Guidelines rewrite • WRDA 07 directs that the Principles & Guidelines be revised to include more emphasis on safety and adaptive management • 'future safety' (resilience) may emerge as an effective screening filter even though the risks are not immediate but linked to projections of future climate change

13. P&G Update • Council on Environmental Quality now involved • Webinar held July 2009 on rewrite of the Guidelines (with the update of procedures to follow in a separate phase) • Update is being considered for government-wide application, not just the Corps and other traditional WR Devmt agencies (Reclamation and NRCS) • Final version will be subject to public and NAS review • http://www.whitehouse.gov/administration/eop/ceq/initiatives/PandG/

14. Principles and Guidelines, U.S. Water Resources Council, 1983 • Highest net benefit to the nation: National Economic Development (NED) • NED is only account that must be used in evaluating alternative plans • Other Accounts: - Environmental Quality - Regional Economic Development - Other Social Effects (Safety)

15. 4 Criteria from the Principles & Guidelines • Efficiency • Completeness • Acceptability • Effectiveness can be applied to underscore the benefits of a resilient system, i.e. the resilient project may be more effective, acceptable, and complete than a less resilient project that is more cost-effective and efficient in the short term.

16. Scenario Planning in P&G Update? • “Scenario planning addresses uncertainty by anticipating plausible scenarios (alternate futures) and establishing a learning-oriented monitoring program so timely adjustments can occur.” (Williams, USFS) • One place the Corps really tries to do this is with Beach Nourishment (projects considered to be continuously in “Construction”)

17. Google NASA Yahoo Lockheed Martin Planning in SF Bay Figures from SFEI and BCDC

18. South SF Bay Shoreline Study Salt Pond restoration and tidal flooding protection to Silicon Valley First Interim: • ~8,000 acres former salt-production ponds • USFWS land ownership • ~15 miles of shoreline • 50-yr period of analysis

20. South SF Bay Shoreline study running models of the without project inundation levels for 3 different future conditions of sea level.

21. South SF Bay Sea Level Rise

22. Hamilton and Bel Marin Keys Wetland Restoration Projects • 2,600 acres of tidal restoration for endangered species • Beneficial placement of up to 24 mcy of dredged material from federal and private navigation channels • Facilitation of closure of former Hamilton Army Airfield Construction of dredge-material pipeline at Hamilton • Site plan for Bel Marin Keys Photo of Hamilton Army Airfield

23. Raising site elevations with material pumped from an offloader in the middle of San Pablo Bay Hamilton site prep ongoing since 2005: Over 5 MCY from Oakland Harbor Deepening and nearby O&M dredging thru fall of 2009; Breach in 2013 Habitats: -Mudflat -Intertidal Marsh -Seasonal Wetland -Upland (Wildlife corridor) 20 years natural sedimentation [13 years with fed funded adaptive mgmt and monitoring] Similar timelines expected with additional BMK parcel Hamilton and Bel Marin Keys Restoration

24. Hamilton-Bel Marin Keys • Consensus was reached on a mix of habitat types (project outputs) that include a relatively high component of seasonal (vs. tidal) wetlands early in the project life • after a moderate amount of sea level rise project will transition to a greater percentage of tidal wetlands • Eventually 100% tidal • 1.5m (by 2100?) would likely require additional actions

25. Hamilton-Bel Marin Keys • Address potential risk of tidal flooding to adjacent communities (perimeter levees). • While the wetlands will absorb some tidal flooding and act as a sort of buffer to flooding, they don’t eliminate all flood risks to the adjacent community – levees are still a part of the plan. • Sufficient land interests must be kept available along the perimeter in case it becomes necessary to increase levee heights and footprints as sea level rises. • Emphasis on resilience in design

29. Coastal Planning Guidance Group • “The end goal of editing the text of the Planning Guidance Notebook is to improve Corps’ Coastal Planners ability to make decisions under uncertain future conditions.” • Group proposes to identify examples: • “These examples of decision tools will walk the user through multiple analyses and give guidance on when a traditional single-scenario National Economic Development or Nat’l Ecosystem Restoration (NED or NER), a cursory sensitivity, or a more robust multi-attribute, multi-scenario utility analysis is appropriate.” • Looking for pre-draft Feasibility studies to be demonstrations • IWR to lead new task force on approaches to use for multi-scenario planning (sea level is just one application of many for this tool) • Assuming P&G update supports, the PGN is to eventually reflect scenario-based decision making (& not just for changing sea levels) • NRC update to sea-level rise scenario curves (& all subsequent updates) and selection of multi-scenario planning techniques will be integral to the PGN update. • Implications of Multi-Scenario Planning: Budget Priorities and Cost-Sharing