OPERATIONAL LANDSCAPE UNITS FOR SF BAY:

February 21, 2017 `

OPERATIONAL LANDSCAPE UNITS FOR SF BAY:

Using nature’s jurisdictions to plan for sea level rise

BCDC ART BAY AREA WORKING GROUP

June 19, 2018

Julie Beagle, Jeremy Lowe, Sam Safran, Katie McKnight, SFEI

Laura Tam, Sarah Jo Szambelan, SPUR

Funded by:

SF Bay Regional Water Quality

Control Board

Marin Community Foundation Moore Foundation

Goals

of today

•

Describe the Operational Landscape Unit (OLUS) Project

•

Project motivation

•

What are OLUs?

●

Create spatial framework

to guide

nature-based adaptation strategies for

sea-level rise

●

“Nature’s jurisdictions”

●

Pairing problems with adaptation

measures

in appropriate places

Project Rationale

Processes that govern the shoreline

happen at the

Bay scale

. Too large

and complex for individual projects.

Project Rationale

1.

Processes that govern the shoreline happen at the

Bay scale

. Too large and complex for individual

projects.

2.

Need to

divide up the Bay

into smaller

manageable pieces: Sea level rise won’t stop at

city boundaries.

Project Rationale

1.

Processes that govern the shoreline happen at the

Bay scale

. Too large and complex for individual

projects.

2.

Need to

divide up the Bay

into smaller

manageable pieces: Sea level rise won’t stop at

city boundaries.

3.

Risk of the

wrong type

of actions in the

wrong

places,

less resilience, and not all the benefits.

4.

Opportunity to maximize

multi-benefit,

nature-based solutions

. More resilience, most

co-benefits, more adaptable over time.

How can this be used?

●

A resource to assist

environmental

review and permitting

●

Guidance for

restoration practitioners

Inform local and regional

vulnerability

Another way of

splitting up the Bay?

• Watersheds

• Poorly defined in flat Baylands

• Bayland Goals segments

• Based on historical wetlands

•

County boundaries often split creeks

•

What is the right scale?

Sonoma

Napa

Solano Marin

Operational

Landscape Units:

Defined

Areas of the

baylands and their watersheds

that

are expected to support a coherent suite of

upland, intertidal, and subtidal ecosystem

functions

as appropriate for

their location in the

Bay,

along with the physical processes of

water

and sediment

needed to sustain these

functions.

Adapted from Verhoeven et al. 2008

upland

intertidal

0%

80% Percent Slope

STEEP HEADLANDS + SMALL VALLEYS Hills Alluvial Plain Baylands Shallow Bay Deep Bay 0% 80% Percent Slope

STEEP HEADLANDS + SMALL VALLEYS ALLUVIAL PLAIN Hills Alluvial Plain Baylands Shallow Bay Deep Bay 0% 80% Percent Slope

Surficial

Geology

Holocene Bay Mud

Fine-grained Holocene Alluvium Coarse-grained Holocene Alluvium Late Pleistocene Alluvium

Holocene beach and dune sand Franciscan Assemblage Great Valley Sequence

STEEP HEADLANDS + SMALL VALLEYS ALLUVIAL PLAIN WIDE ALLUVIAL VALLEY Hills Alluvial Plain Baylands Shallow Bay Deep Bay 0% 80% Percent Slope

SAN PABLO BAY

WIDE ALLUVIAL

VALLEYS

OLU breaks between major tidalsheds

Used to split otherwise contiguous baylands

e.g. Suisun Slough drainage vs. Montezuma Slough drainage Napa-Sonoma drainage vs. Petaluma drainage

Dividing geomorphic units along

the shoreline

ALLUVIAL FANS &

ALLUVIAL PLAINS

OLU breaks at the apex of alluvial fans

Generally located where the baylands are relatively narrow

e.g. Alameda Creek fan apex @ Dumbarton Point San Mateo Creek fan @ Coyote Point

HEADLANDS &

SMALL VALLEYS

OLU breaks at the apex ofmajor points

Determined where distance to deep water reached a local minimum

Area of analysis

●

Back boundary

○ Baylands + 5 m SLR + Transition zone with SLR

●

Side boundaries

Subtidal

boundary

Influence of wave height on critical depth of resuspension

Watershed inputs

●

Sediment loads

●

Freshwater (Rivers and Creeks)

●

Nutrients

●

Creek-Bay Interfaces

Marshes &

tidal flats

Wave heights

Bayshore Inventory (SFEP DWR Prop 84)

Low-density residential Low-density commercial and industrial High-density downtowns Open Space Small-lot residential with mixed use Job-dense suburban centers

Corte Madera San Rafael Carquinez South Mission-Islais Alameda Mowry

Nature based measures (examples)

•

Oyster reef creation

•

Submerged vegetation restoration

•

Mudflat augmentation

•

Beach creation (sand, cobble, shell)

•

Marsh restoration (various)

•

Polder management

•

Horizontal levee creation

•

Migration zone preparation

Adaptation measures

Regulatory, Financial, Policy tools

•

Easements

•

Building restrictions

•

Policy changes

•

Zoning changes or overlays

•

Buyouts

•

Transfer of Development Rights

Pairing Problems with Measures

Problem

Cause

Example measure

Wave overtopping or erosion of levee with wide foreshore

Large waves reach levee Marsh, fine beach, horizontal levee Waves overtopping or erosion with

narrow foreshore

Close to deep water Coarse beach

Combined flooding Loss of floodplain Retention basins, setback levee

Combined flooding Channel conveyance Tidal restoration, geomorphic channels Loss of marsh area Wave erosion of scarp Coarse beach, oyster reef

Loss of elevation capital Low accretion rate Strategic placement No space to migrate marsh Development up to levee Horizontal levee

Horizontal levees

Methods and notes:

● For each OLU determined approximate needed levee height: = storm surge height + swell height + SLR

● Based on height, determined needed levee width assuming slope of 1:30 ● Mapped horizontal levee opportunities where potential marsh habitats

(see “Marsh restoration”) at least this wide front developed areas (NLCD 2011)

Potential marsh

Developed areas

Horizontal levee opportunity

500-year storm surge height 1.5 m SLR 100-year swell height

Needed levee height

1:30 slope

Needed levee width

* strongly influenced by high swell along outer parts of OLU; plan to recalculate for inner bay only

Horizontal levees

Methods and notes:

● For each OLU determined approximate needed

levee height:

= storm surge height + swell height + SLR ● Based on height, determined needed levee

width assuming slope of 1:30

● Mapped horizontal levee opportunities where potential marsh habitats (see “Marsh restoration”) at least this wide front

Submerged vegetation restoration Oyster reef

creation Mudflat augmentation Beach creation

Polder

management Tidal marsh restoration

Horizontal levee

construction Migration space preparation

Analysis in

Measures by OLU type

DRAFT

Vulnerability

Physical

Processes &

Drivers

Also sediment load (see large map)

Richardson Bay

s

Opportunities MapS

lack of migration spaced

low elevation capitald

creek floodingd

combined fluvial flooding

●

Technical Advisory Committee

Peter Baye, Coastal Ecologist

Mark Stacey, UC Berkeley

○

Roger Leventhal, Marin County Flood

Kristina Hill, UC Berkeley

○

Andy Gunther

●

Regional Advisory Committee

Luisa Valiela, EPA

○

Naomi Feger, RB2

○

Lindy Lowe, formerly BCDC

Matt Gerhart, SCC

○

Caitlin Sweeney, SFEP

○

David Lewis, Save the Bay

Technical

feedback

Check out the “All Data” tab

of the

Resilience Atlas:

Resilienceatlas.sfei.org

or

sfei.org/projects/OLUs

February 21, 2017

Contact Us:

THANK YOU

Thanks to our team: Katie McKnight, Sam Safran, Letitia Grenier Laura Tam, Sarah Jo Szambelan, SPUR

Funded by: SF Bay Regional Water Quality Control Board (thank you!)