Maps

PDF file Each map is available as a PDF and will require Adobe Acrobat Reader for online viewing. Click on the maps to open.They range in size from 300 KB to 1.5 MB.

Watersheds

 

Vegetation Maps

Vegetation

Bolinas Lagoon

Vegetation

Estero Americano

Vegetation

Gallinas Creek

Vegetation

Miller Creek

Vegetation

Novato Creek

Vegetation

Pt. Reyes

Vegetation

Richardson Bay

Vegetation

Ross Valley

Vegetation

Rush Creek

Vegetation

San Antonio Creek

Vegetation

San Rafael Creek

Vegetation

Southern Coastal Creeks

Vegetation

Stemple Creek

Vegetation

Tomales Bay

 

 

Fish Maps

Fish

Bolinas Lagoon

Fish

Estero Americano

Fish

Miller Creek

Fish

Novato Creek

Fish

Pt. Reyes

Fish

Richardson Bay

Vegetation

Ross Valley

Fish

San Rafael Creek

Fish

Southern Coastal Creeks

Fish

Stemple Creek

Vegetation

Tomales Bay

 

 

Land Use Maps

Land Use

Bolinas Lagoon

Land Use

Estero Americano

Land Use

Gallinas Creek

Land Use

Miller Creek

Land Use

Novato Creek

Imperviousness

Pt. Reyes

Land Use

Richardson Bay

Land Use

Ross Valley

Land Use

Rush Creek

Land Use

San Antonio Creek

Land Use

San Rafael Creek

Land Use

Southern Coastal Creeks

Land Use

Stemple Creek

Land Use

Tomales Bay

 

 

Imperviousness Maps

Vegetation

Bolinas Lagoon

Imperviousness

Estero Americano

Imperviousness

Gallinas Creek

Imperviousness

Miller Creek

Imperviousness

Novato Creek

Imperviousness

Pt. Reyes

Imperviousness

Richardson Bay

Imperviousness

Ross Valley

Imperviousness

Rush Creek

Imperviousness

San Antonio Creek

Imperviousness

San Rafael Creek

Imperviousness

Southern Coastal Creeks

Imperviousness

Stemple Creek

Imperviousness

Tomales Bay

 

 

Flood Zones

 

Flood Zone Maps

Map of Novato

Zone 1 Novato

Map of Mill Valley/Richardson Bay

Zone 3 Mill Valley

Map of Bel Aire Area (Tiburon)

Zone 4 Bel Aire

Map of Stinson Beach

Zone 5 Stinson Beach

Map of San Rafael Meadows

Zone 6 San Rafael Meadows

Map os Santa Venetia

Zone 7 Santa Venetia

Map of Ross Valley

Zone 9 Ross Valley

Map of Inverness

Zone 10 Inverness

 

 

Watershed History

 

Ross Valley 2005 Flood

Ross Valley Watershed

Ross Valley Watershed.
San Anselmo/Corte Madera Creek is the primary drainage channel for the 28 square mile Ross Valley Watershed.

Ross Valley average rainfall

Average Annual Rainfall.
The Ross Valley Watershed receives some of the highest annual rainfall amounts in the Bay Area.

5 day Hydrograph and Rain

Five Day Hydrograph & Rain.
Seven inches of rain fell on the Ross Valley Watershed in the two weeks prior to the flood. Because of this near-saturated condition, the earth had little or no capacity to absorb stormwater on December 31, 2005.

12-2005-Hydrograph+Rain

December 2005 Hydrograph & Rainfall.
At 2:00 am on December 31, 2005, Corte Madera Creek was already at flood stage of 19 feet. The strongest part of the storm occurred from 3:00 am to 6:00 am. Flood waters topped the banks at Ross and San Anselmo at the same time. The flood crested at 22.5 feet, 3.5 feet above flood stage at Ross.

Alluvial Soil

Alluvial Soil.
Alluvial soils consist of sediment carried and deposited by flowing water over time. This map shows the historic flood flows on the valley floor - everywhere there is alluvial soil. In the Ross Valley, these areas are highly developed.

Reach-Map

Reach Map.
Each of the six reaches have unique conditions that both support and restrict high creek flows.

Flood-Path+Depth-(Soils)

Flood Path and Depth (soils).
The historic flood plain, indicated by the tan color alluvial soil, far exceeds the extent of the December 31, 2005 flood, indicated by the red flooded parcels.

Reach-6-Fairfax

Reach 6 - Fairfax.
The culvert below the Fairfax fire house and city hall is the primary cause of flooding in Fairfax.

Reach5-Sleepy-Hollow-Cr

Reach 5 - Sleepy Hollow Creek.
The bridges along Sleepy Hollow Creek restrict the flow down to San Anselmo Creek. This reduced capacity is exacerbated by the constrictions downstream, which back the water up like a traffic jam.

Map of Ross Valley

Reach 4 - San Anselmo.
Downtown San Anselmo has six major constrictions, four of which are within 500 feet of each other. These severe constraints caused extensive flooding in San Anselmo and downstream in Ross, Kentfield and Larkspur.

Reach3-Ross Creek

Reach 3 - Ross Creek.
Ross Creek flows out of Phoenix Lake and joins Corte Madera Creek. It has been estimated to carry up to 1000cfs. The bridge constrictions at Shady Lane forced water out of the channel and increased the flood flow coming from San Anselmo.

Reach2-Concrete Channel

Reach 2 - Concrete Channel.
Designed in the 1960s, the concrete channel conveys approximately 3500cfs. In the December 31, 2005 storm, there was no reported overflow of the concrete channel. In fact, water from Kent Avenue flowed over College of Marin property and back into the concrete channel.

Reach1-Earthen Channel

Reach 1 - Earthen Channel.
The earthern channel was designed by the Army Corps of Engineers to convey 9600cfs. During the December 31 storm, this channel carried both normal channel flow and overland flow. Sedimentation over the last 15 years has decreased the capacity to an unknown amount. This section requires regular dredging, according to the Army Corps Interim Operation & Maintenance Manual.