The natural or unnatural process of eroding or being eroded by wind, water, or other natural agents.
In Marin, erosion along creek banks is very common and can come in many forms; bank scour, bank slumping/land slides, bank undercutting, bed scour/head-cutting, lateral bank erosion and incision.
In Marin, when it rains, it pours and as the droplets hit the bare soil, water accumulates on the surface and increases runoff which takes soil with it. The more impermeable surfaces that exist (driveways, sidewalks, roofs), the more runoff that is created which in turn speeds up, taking soil with it. Think of it like the ‘snowball effect’, accumulating more and more soil when it comes in contact with bare ground while rushing to the nearest stream. When high volumes of water sheet off into the streams instead of recharging the water table on the landscape, the large amount of water runs quickly downstream, scouring the bed and banks as it goes.
A lack of vegetation on the landscape to slow the flow, spread the flow and sink the flow, the more issues that will arise in Marin’s watersheds. For this reason, landowners and land managers should protect areas of exposed soil with native vegetation (http://www.cnpsmarin.org/) and weed-free mulch (http://www.marinwater.org/rebates).
Erosion Control Supplies
Water Components & Building Supply, Inc. Located at 44 Simms St. San Rafael(415)-451-1780
- Straw logs and bales (certified weed-free rice straw)
- Silt fence
- Jute netting
- Sandbags (prefilled/empty)
- Gravel bags
- Snake bags
- Wood stakes
- Sisal twine
- Seed mixes
Work-Trade for Plants
If you’re in need of native plants but cannot afford the cost, email Preston Brown, Watershed Biologist with Salmon Protection and Watershed Network (SPAWN) for opportunities to volunteer in trade for plants. ONE hour of rewarding volunteer labor bears the fruit of TWO native plants, genetically specific to the San Geronimo Valley. Contact Preston to sign-up at firstname.lastname@example.org and click HERE to find out about upcoming volunteer opportunities with SPAWN..