Erosion Control: Castro Valley vs Fremont
How do erosion control rules compare between Castro Valley, CA and Fremont, CA?
Fremont has fewer restrictions than Castro Valley.
Castro Valley, CA
Alameda County
Alameda County requires erosion control during the rainy season (October 1 to April 30). Projects over 1 acre need a Construction General Permit and a SWPPP.
View full Castro Valley rules →Fremont, CA
Alameda County
Fremont requires erosion and sediment control BMPs on all construction sites and mandates year-round and wet-season plans for hillside grading projects.
View full Fremont rules →Key Facts Comparison
| Fact | Castro Valley | Fremont |
|---|---|---|
| Wet season | October 1 to April 30 | - |
| Permit trigger | 1 acre disturbance | - |
| Plan required | SWPPP with QSD | - |
| Required BMPs | Silt fences, wattles, inlets | - |
| Penalty | Up to 10,000 per day | - |
| Wet Season | - | Oct 1 to Apr 30 |
| SWPPP | - | Sites 1 acre or larger |
| BMPs | - | Required all sites |
| Hillside | - | Geotech review required |
| Contact | - | (510) 494-4460 |
Highlighted rows indicate differences between cities.
Castro Valley FAQ
Do I need a SWPPP for a small home project?
Only if you disturb 1 acre or more, which is unusual for single-family projects. Smaller projects still need basic erosion control BMPs during the wet season.
What BMPs work best on my hillside lot?
Combine silt fences or fiber rolls at the downslope perimeter, straw wattles along contours, and rapid revegetation or hydroseeding of disturbed areas before October 1.
Fremont FAQ
Do small home additions need erosion control?
Yes, any disturbed soil requires at least basic BMPs like silt fence and a stabilized construction entrance.
What counts as an acceptable BMP?
Per the CA Stormwater BMP Handbook: silt fence, fiber rolls, stabilized entrances, inlet protection, and perimeter controls.
Compare other topics
See how Castro Valley and Fremont compare on other ordinance categories.
Want to add a third city?
Use our full comparison tool to compare up to three cities.
Open Comparison Tool