Elkhorn Slough Tidal Wetland Project

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1 Elkhorn Slough Tidal Wetland Project Joint Meeting Strategic Planning Team and Science Panel September 23, 2009 Funding National Oceanic and Atmospheric Admin. David and Lucille Packard Foundation Resources Legacy Fund Foundation Environmental Protection Agency California Coastal Conservancy Bryan Largay Elkhorn Slough National Estuarine Research Reserve

2 Purpose of this meeting Provide project update Discuss management priorities and tradeoffs Receive guidance on project design and adaptive management Objectives Discuss predicted impacts of the project Identify the species and habitats that are most important to manage for in the Parsons Slough complex To improve the structure design To guide Adaptive Management Discuss tradeoffs between those species and habitats Prioritize species and habitats to resolve tradeoffs

3 Unresolved issues for the Tidal Wetland Project important but less urgent Decision making on the mouth Sediment supply projects Restoration of water quality Restoration of tidally restricted sites Some of these require low but consistent levels of effort. Good partnership opportunity.

4 Tidal Wetland Project status Joint meeting of the Strategic Planning Team and Science Panel recommended the Parsons Slough Sill Design, permitting and adaptive management planning are underway Project Next Step How do we best design and manage the structure to avoid or minimize undesirable effects? Which effects are most undesirable? Overarching goal Maximize ecologic health

5 Recovery Act Grant award from the NOAA Restoration Center (June 30) Build Parsons Slough Sill Implement Adaptive Management Process Integrate the community and stakeholders into the process Construction timeline: 15 months 24 month intensive monitoring period

6 Parsons Slough Project Decision Process Role of the group today Improve the project with advice and guidance Learn about how to help by participating further Authority rests with DFG The site is DFG property, management is ultimately a DFG decision. Straw man management priorities To be presented later The recommendation of ESNERR staff Something to build on and react to

7 Parsons Slough Project Tasks Outreach Design Regulatory Compliance Adaptive Managemnt Project Managemnt Staff Lead Working Groups Contractors

8 Parsons Slough Project Working Groups Outreach Design Regulatory Compliance Adaptive Management Plan Development and Process Design Water quality Tidal scour Salt marsh die back Benthic invertebrates and other indicators Sharks and other fish Marine mammals Others? Project Management Membership ESNERR staff lead Managers Key agency staff Scientists Other stakeholders Reports by contractors

9 The Adaptive Management budget was cut Track progress on Goals Minimize impacts Requested $800,000 Awarded $200,000 Focus: Water Quality, Adaptive Management Plan development Options Proceed with reduced scope of work Proceed with less monitoring Pursue funding Take advantage of funding if available Delay restricting the sill until funding is secured?

10 Elkhorn Slough: The lay of the land Salinas Castroville Parsons Slough Elkhorn Slough Moss Landing Monterey Bay

11 Elkhorn Slough An exceptional resource 750+ species of animals 50,000+ visitors each year world class scientific research

12 Salt Marsh & Tidal Creeks 800 acres Mudflat 1,600 acres Tidal Channels 300 acres

13 Elkhorn Slough is changing Soft mud is scoured away Marsh is dying back, Banks are eroding China Camp SF Bay

14 Marsh Loss 200 acres of marsh have died back prediction: 550 acres more within 50 years

15 Soft Mud Habitats Scoured away deepening of main channel Elkhorn Slough Thalweg Depth (meters from MLLW) Distance from harbor mouth (meters)

Problem Solving: Strategic Planning Team Role: Primary decision-making body FEDERAL Monterey Bay National Marine Sanctuary National Marine Protected Areas U.S. Army Corps of Engineers U.S. Environmental Protection Agency U.

16 Problem Solving: Strategic Planning Team Role: Primary decision-making body FEDERAL Monterey Bay National Marine Sanctuary National Marine Protected Areas U.S. Army Corps of Engineers U.S. Environmental Protection Agency U.S. Fish and Wildlife Service FEDERAL & STATE Elkhorn Slough National Estuarine Research Reserve NOAA/CA DFG (lead)* STATE CA Coastal Commission CA Coastal Conservancy CA Department of Fish and Game LOCAL Monterey County Moss Landing Harbor District NONPROFIT, ACADEMIC, CORPORTATE Moss Landing Marine Laboratories CA State University Monterey Bay Elkhorn Slough Foundation San Francisco Estuary Institute The Nature Conservancy The Ocean Conservancy University of San Francisco Union Pacific Railroad

17 Technical Guidance: Science Panel Role Who Provide and review scientific information Biologists, hydrologists, geologists, marine chemists Over 80 members U.S. Geological Survey Stanford University Moss Landing Marine Laboratories U.S. Environmental Protection Agency U.S. Army Corps of Engineers University of California Santa Cruz University of California Davis Monterey Bay Aquarium Research Institute California State University Monterey Bay Monterey Bay National Marine Sanctuary Point Reyes Bird Observatory ES National Estuarine Research Reserve San Francisco State University California Department of Fish and Game

18 Root causes of change: Moss Landing Harbor

19 Conceptual model of change Before Moss Landing Harbor: the sand bar at the mouth dissipated the energy of Monterey Bay tides Monterey Bay tides Elkhorn Slough tides salt marsh thrives sand bar soft mud accumulates Monterey Bay sinuous channel Elkhorn Slough

20 Present conditions After Moss Landing Harbor: The deep channel transmits the ocean s s energy into the slough Monterey Bay tides Elkhorn Slough tides salt marsh drowns soft mud is scoured away Monterey Bay Highway 1 bridge Elkhorn Slough

21 Root causes of change: Parsons Slough - diking, draining and breaching After subsidence the land has dropped 3 to 5 feet It covers just 15% of the land of Elkhorn Slough But contributes over 35% of the daily tidal exchange

22 Historical reference condition <1870 (estimated) Before Moss Landing Harbor Before Parsons was drained Monterey Bay tides Elkhorn Slough tides salt marsh thrives sand bar soft mud accumulates Monterey Bay sinuous channel Elkhorn Slough

23 Historical condition ~1931 Before Moss Landing Harbor After Parsons was drained Tidal Barrier Monterey Bay tides Elkhorn Slough tides Land subsides sand bar soft mud accumulates Monterey Bay sinuous channel Elkhorn Slough

24 After the harbor was opened ~1955 Moss Landing Harbor is opened Tidal scour begins Tidal Barrier Monterey Bay tides Elkhorn Slough Land subsides further soft mud begins to scour Monterey Bay straight channel Elkhorn Slough

25 Parsons Slough opened to the tides ~1985 Parsons Slough is opened Tidal scour accelerates Monterey Bay tides Parsons Slough tides soft mud is scoured away Monterey Bay Elkhorn Slough

26 Root causes of change: Salinas River diversion Salinas Salinas River Castroville Parsons Slough Elkhorn Slough Moss Landing Monterey Bay

27 Salinas River in Flood, 1995 Watershed area: 2.5 million acres

28 Sediment supports salt marsh With a greater sediment supply Salt marshes can keep pace with rising waters Monterey Bay tides Elkhorn Slough tides salt marsh rises soft mud is scoured away Monterey Bay Highway 1 bridge Elkhorn Slough

29 Tidal Wetland Project Planning Process 30+ Meetings on History, Ecology, Hydrology Brainstorming, Expert guidance Goal 1. Conserve Estuarine Habitats More natural rate of change Goal 2. Restore estuarine habitats Emphasize habitats with highest rates of loss Goal 3. Restore processes that sustain the system Water and sediment Objectives prioritize: salt marsh soft subtidal habitats tidal creeks tidal brackish marshes decrease tidal prism increase sediment supply

30 Planning Principles (17) Guidelines and constraints Examples: Consider the broadest range of approaches Accommodate economic activities Minimize ongoing maintenance Prioritize projects that improve water quality

31 The plan did not define all the acceptable tradeoffs Examples of agreement: Minimize impact to economic activity Avoid salt marsh farms Examples of unresolved issues: Should sea otters be excluded to restore marsh? What loss of mudflat is acceptable for shorebirds? Where do you draw the line?

32 Management alternative: New Ocean Inlet Restores a sinuous shoaling inlet Effectiveness: High Cost: $100 million Impacts: Many Risk: High Reversible: No Image: Google Earth

33 Management alternative: Sill at Highway 1 Dissipates the energy of the tides Effectiveness: Medium Cost: $30 million Impacts: Some-Many Risk: High? Reversible: Maybe Image: Google Earth

34 Management alternative: Sill at Highway 1 A submerged tidal barrier near the mouth of the slough dissipates tidal energy Monterey Bay tides Elkhorn Slough tides salt marsh survives Sill soft mud deposits Moss Landing Harbor Elkhorn Slough

35 Water quality risk Less tidal exchange often leads to poor water quality Elkhorn Slough is already at risk

Recommended alternative: A tidal barrier at Parsons Slough Moderate reduction of the tides in Parsons Slough Slow currents throughout Elkhorn Slough Elkhorn Slough Effectiveness: Low-Medium Cost: $2

36 Recommended alternative: A tidal barrier at Parsons Slough Moderate reduction of the tides in Parsons Slough Slow currents throughout Elkhorn Slough Elkhorn Slough Effectiveness: Low-Medium Cost: $2 million Parsons Slough sill location Impacts: Few (relatively) Risk: Low (relatively) Reversible: Yes - Maybe Approach An adjustable structure With detailed monitoring That triggers management actions To manage risk to water quality, fish and wildlife movement

37 Parsons Slough Sill: Restricted Less tidal exchange Soft mud accumulates? Salt marsh recovers? Monterey Bay tides Parsons Slough tidal scour slows (stops?) Monterey Bay Elkhorn Slough

38 Parsons Slough Sill: Open Full tidal exchange Maintains water quality Restores present habitat extent Monterey Bay tides Parsons Slough tidal scour resumes Monterey Bay Elkhorn Slough

39 Effect on current velocity in Elkhorn Slough Current velocity in Elkhorn Slough downstream of Parsons under the Narrow and Deep configuration of a submerged sill at Parsons Slough existing condtions Narrow, Deep configuration current velocity (feet/sec) /14/05 12/15/05 12/16/05 12/17/05 12/18/05 12/19/05 Analysis: Moffatt and Nichol simulation date

44 Progress on TWP Goals Tidal Wetland Project Objective In Parsons Slough In the Rest of Elkhorn Slough Reduce the rate of salt marsh loss Reduce the rate of subtidal channel erosion likely increase Reduce the rate of soft sediment loss Reduce the rate of tidal creek conversion likely no change Restore salt marsh Restore brackish marsh Restore freshwater/salt water transitions Restore soft sediment habitats Reduce tidal prism Restore tidal exchange to restricted areas possible increase Restore sediment to subsided areas Use pilot projects for learning opportunities

45 How the proposed structure affects the ecosystem Construction Noise, machinery Physical effects Physical barrier partially adjustable Velocity barrier partially adjustable Others? Habitat changes Hard substrate not adjustable Shift mudflat to open water adjustable Shift mudflat to salt marsh adjustable Water quality Increased residence time adjustable Shallower, less oxygen available partially adjustable

46 Example of Trade Offs we hope to discuss today Structure is more restrictive In Elkhorn Slough Tidal prism reduction Sediment retention In Parsons Slough Salt marsh restoration Structure is less restrictive In Elkhorn Slough Fewer benefits In Parsons Slough Better water quality More shorebirds

47 Advancing goals while minimizing impacts Management Target, defined Something we measure to guide management Design of the structure Adjustment of the structure Linked to species or habitat by conceptual model Links monitoring to a species or habitat and to a management action

48 Monitoring: Potential management targets Species and Habitats What people care about Physical, chemical and biological drivers of ecologic health Management strategies operate here. Monitoring parameters as surrogates for ecologic health Things we can measure easily, reliable indicators

49 Monitoring and Management Conceptual models Ecologic Health conceptual model Monitoring parameters

50 Conceptual model to identify monitoring approach Example: More restrictive sill setting > Reduced tidal range > Longer residence time > Greater abundance of algae > Lower dissolved oxygen > Reduced abundance of fish

51 Adaptive management cycle Management and monitoring cycle Decision process defined Process revision built in

52 Adaptive Management and Monitoring Inner Loop Are our Management Targets being met? Action > monitoring > decide: action/no action Easy to measure parameters Outer Loop Are we monitoring the right things Process refinement: make sure the conceptual models are right Species or habitats with slower response management decision Process revision monitoring

53 Elkhorn Slough Tidal Wetland Project working to preserve all the habitats of Elkhorn Slough despite the changes, it remains a magical place Bryan Largay Elkhorn Slough National Estuarine Research Reserve bryan@elkhornslough.org

Appendix C. Past and Current Management of Selected Tidal Wetland Sites

Appendix C. Past and Current Management of Selected Tidal Wetland Sites Maps and photographs of wetland sites can be found at http://www.elkhornslough.org/tidalwetlandproject. Site 1. Parsons Slough/South