RESTORATION OPPORTUNITIES ON NOVATO CREEK HAMILTON AND BEYOND Tom Gandesbery State Coastal...

RESTORATION RESTORATION OPPORTUNITIES ON OPPORTUNITIES ON

NOVATO CREEK NOVATO CREEK HAMILTON AND BEYONDHAMILTON AND BEYOND

Tom GandesberyState Coastal Conservancy

tgandesbery@scc.ca.gov

WWW. SCC.CA.GOV

H/BMK Who is Involved?

• Consulting Firms: PWA and Noble / NHC• Marin County Flood Control / Public Works• USACOE• City of Novato• BMK CSD and several members of community• Water District• Sanitary Districts (2)• Home Owner’s Associations• Environmental Community• Trail Advocates• NOAA

Landscape Level Design

Sonoma Baylands

Historic Context

North Bay Project Potential

BMK V 1600 ac -Owned by SCC

NAF ~200ac Owned by SLC

Airfield 622ac -Owned by SCC

Project is 3 Properties = 2600 acres

Bel Marin Keys Homes

Looking East from over Hwy 101

LTMS ~ Hamilton Link

Partners involved in:

Pre-project planning (Since 1993)

1999 Congressional Approval of Hamilton

Federal and State Appropriations

Stakeholder Involvement (Local Gov and NGO)

Fosters Collaboration: Work between agencies

Support by Maritime Interest Groups

LTMS StrategyBCDC / USEPA / RWQCB / USACOE

LTMS Program EIS/EIR (1994) and ROD (1999)Disposal and Reuse Goal of 40/40/2020-Year Planning Horizon40% Ocean Disposal 40% Reuse20% In-Bay

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

1999-2001 2002-2004 2005-2007 2008-2010 After 2010

COE

Medium

Small

E x is t in g D is p o s a l L im i t W e t Y e a r

E x is t in g D is p o s a l L im i t D r y Y e a r

H o w W i l l W e G e t T h e r e ?

T r a n s i t i o n P e r io dH o w W i l l W e G e t T h e r e ?

T r a n s i t i o n P e r io dM

illio

ns o

f C

ubic

Yar

ds/Y

ear

Multiple Objectives

1. Marsh Restoration using Dredged Sediment ( LTMS)

2. Tidal Marsh Habitat benefiting Endangered Species Part of a Larger Initiative (see map)

Habitat Linkages With in USFWS / DGS Refuge System

3. Well Planned Reuse of Military Lands BRAC No-Cost Conveyance to SCC

• Scan pdf

Total Project Conceptual Design

Design ObjectivesCreation of 3 habitat types

tidal wetlandsseasonal wetlandsuplands

To benefit an array of speciesendangered (saltmarsh harvest mouse, clapper rail)

shorebirds (e.g. greater yellowlegs, long-billed curlew)

local wildlife (e.g. marsh hawk, voles, butterflies)

With minimal long-term maintenance

Hamilton Wetlands Restoration Project

Authorized in WRDA 1999 - $55,200,000 • Purpose: Ecosystem and Wetlands Restoration• Restores approximately 990 acres of habitat including:

– 570 Acres of Coastal Salt Marsh– 120 Acres of tidal channels and intertidal habitats

• Accommodates approximately 10.6MCY of dredged material

• 13 years of Adaptive Management Post Breach• Complete Restoration – 20 Years

Regardless of the availability of dredged material, the bay ward levee breach would be completed no later than 8 years after initiation of site preparation to ensure that marsh establishment would not be delayed

First DM Restoration Sonoma Baylands (Before)

(After)

Wave – Fetch Berms

Pilot Channel (Mosquito Ditch)

Habitat Types at Hamilton

Hamilton Site Template

Hamilton Site at 10 Years

Hamilton Site at 50 Years

Progress 3 Major Phases

• For Airfield– Built 3 out of five levee segments– Seasonal Wetland Design ~50% complete– Trail plan complete– DM placement cells for first phase compete– Major DM placement - start winter of 2007 – 2005 rec permits – Monitoring required

Antenna Field Status

190 Acres

~ 30 Acres in southeast corner used for:

Shooting range

Antenna field

Burn Pits (fire training, etc)

Spot Removals completed in 1990s

Clean-up Plans are in a regulatory process

After remediation, restored as Phase II or III of the project

Cleanup scheduled for 2008

BMKV Status

Awaiting Congressional Approval to Add to Hamilton (WRDA)Elements completed:

Supplemental EIS/EIR for Bel Marin Keys Unit V Completed December 2003.

General Reevaluation Report (GRR) a revision to the FS

Draft Chief’ Report written

Revised Cost Estimates

Toxics Remediation

This is another Workshop!• Done by Army / Navy BRAC• 1990s - BRAC work within Hamilton • Contaminants typical of an large airport• $70 Million (about) on soil cleanup - no groundwater• Cleanup complete this FY • Cleanup plan adopted 2003• Low level (residual) DDT in soil was managed by project

Public Access

• Trail will run western parameter of site • To BMK Blvd North and connect to ? South• User –wildlife interaction

– Nesting birds most sensitive

• Sophisticated Trail Design(Mixture of cable fencing,moat, signage, elevation)

Required monitoring– Methods? – Applicable to Adaptive Management

•

Site is subsided show cross sect

The Project at HAAFHabitat Upland Tidal wetland Seasonal wetland

Goal local wildlife endangered species shorebirds migratory species

Physical corridor tidal action tidal inundationcorollaries restricted access sedimentation ppt inputs

escape terrain channel network/form high soil salinity

Vegetation native overstory Salicornia open pannes,mixed understory stressed

Salicornia,matrix of

native wetland

Challenges weeds design template design w/ man optionsinund/salinity

regimeweeds

Uncertaintylow low to moderate high

Seasonal Wetland Design

High Priorities for Monitoring

PhysicalPlaced sediment elevation (No overfilling!)Levee erosion and stability (flood control)

Channel developmentHydrology inside and outboard

ChemicalMeHg (Corps, Calfed)Conventionals and sediment (e.g. redox)

BiologicalBird use Clapper rail and SMH MouseFish use

Design

Monitoring

Evaluation

Decision

Implementation

salinity, indundation, veg, birds

Evaluation

Strategy

Design

Adaptive Management:Monitoring specific

to objectives, uncertainties

Modified from Sit and Taylor 1998

time

reso

urc

e q

ual

ity

HAAF ADAPTIVE MANAGEMENT CYCLES

AVAILABLE STUDIES

• Collins, L July 1998, Sediment Sources and Fluvial Geomorphic Processes of Lower Novato Creek Watershed.

• Prunuski Chatham, Inc, April 2001, Novato Creek Watershed, Erosion Inventory and Sediment Control Plan

• Phillip Williams and Associates, May 7, 2002, Flood and Sediment Study for Lower Creek

(All are reports to or for Marin County Flood or PW)

OTHERS?

Results of BMK H&H2 lead to….

• Confirms previous findings

• Quantifies some parameters

• Poses new questions– Like…. upstream flood routing– Influence of Black Point as tidal basin

Novato Creek Hydraulic Modeling

northwest hydraulic consultants

May 2006

Study Objective

• Investigate potential hydraulic impacts to Novato Creek if BMK-V parcel is restored to tidal wetlands

– Develop 1-d HEC-RAS model for existing conditions

– Develop 1-d HEC-RAS model for project conditions

– Conduct comparative simulations of different flooding scenarios with coincident high flow and tide

Study Area

Bel Marin Keys Unit V

(BMK-V) expansion site

North LockNorth Lock

South LockSouth Lock

Bel Marin Bel Marin KeysKeys

developmentdevelopment

Pacheco Pacheco PondPond

San Pablo San Pablo BayBay

Novato Novato CreekCreek

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72

Time (hrs)

Inflo

w (c

fs)

USACE (1987) 100-yr hydrograph

Hydrograph scaled to peak flow of 8,000 cfs (100-yr flood)

Hydrograph scaled to peak flow of 3,420 cfs (10-yr flood)

Novato Creek

Inflow Flood Hydrographs Novato CreekNovato Creek

USACE 100-yr peak flow 6,230 USACE 100-yr peak flow 6,230 cfscfs

100-yr peak flow 8,000 cfs100-yr peak flow 8,000 cfs

10-yr peak flow 3,420 cfs10-yr peak flow 3,420 cfs

Arroyo San JoseArroyo San Jose

100-yr peak flow 2,403 cfs100-yr peak flow 2,403 cfs

10-yr peak flow 1,340 cfs10-yr peak flow 1,340 cfs

Pacheco CreekPacheco Creek

100-yr peak flow 1,041 cfs100-yr peak flow 1,041 cfs

10-yr peak flow 582 cfs10-yr peak flow 582 cfs

0

1,000

2,000

3,000

0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72

Time (hrs)

Inflo

w (c

fs)

100-yr hydrograph

10-yr hydrograph

Arroyo San Jose

0

1,000

2,000

3,000

0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72

Time (hrs)

Inflo

w (c

fs)

100-yr hydrograph

10-yr hydrograph

Pacheco Creek

Modeling Scenarios

19 flood and geometric scenarios:

• 100-year river flood & 10-year tide– Existing conditions (Baseline/No bridges/Leveroni levee

breach/Accreted)– Project conditions (Project/No bridges/Leveroni levee breach)

• 10-year river flood & 100-year tide– Existing conditions (Baseline/No bridges/Leveroni levee breach)– Project conditions (Project/No bridges/Leveroni levee breach)

• 100-year river flood & 100-year tide– Existing conditions (Baseline/No bridges/Leveroni levee breach)– Project conditions (Project/No bridges/Leveroni levee breach)

Flooding Flooding patternpattern

ExistingExisting

ProjectProject

Modeling Results –100-year flood & 10-year tide

Modeling Results –10-year flood & 100-year tide

Flooding Flooding patternpattern

ExistingExisting

ProjectProject