Stormwater Management: Hesperia vs Rialto
How do stormwater management rules compare between Hesperia, CA and Rialto, CA?
Hesperia and Rialto have similar restriction levels.
Hesperia, CA
San Bernardino County
Hesperia is a regulated small MS4 under the California State Water Resources Control Board's Phase II General Permit (Order WQ 2013-0001-DWQ as amended). The city's Storm Water Management Program (SWMP) is enforced by the Hesperia Engineering Department. All construction sites disturbing one acre or more must obtain coverage under the statewide Construction General Permit (Order 2022-0057-DWQ) and prepare a SWPPP; smaller residential sites must implement Erosion and Sediment Control Plans (ESCPs). Post-construction Water Quality Management Plans (WQMPs) are required for development projects per the Phase II Permit's post-construction provisions. Discharge of anything other than uncontaminated stormwater into the MS4 is prohibited.
View full Hesperia rules →Rialto, CA
San Bernardino County
Rialto is a co-permittee on the San Bernardino County MS4 NPDES Permit issued by the Santa Ana Regional Water Quality Control Board (Order R8-2010-0036, NPDES No. CAS618036) and enforces stormwater quality controls under Title 13 (Public Services) of the Municipal Code. All non-stormwater discharges to the storm drain (including wash water, paint, oil, and sediment) are prohibited, and construction sites ≥1 acre require coverage under the Statewide Construction General Permit and a SWPPP.
View full Rialto rules →Key Facts Comparison
| Fact | Hesperia | Rialto |
|---|---|---|
| Permit basis | Phase II MS4 Order WQ 2013-0001-DWQ (as amended) | - |
| Regional oversight | Lahontan Regional Water Quality Control Board (Mojave River Watershed) | - |
| SWPPP trigger | Construction projects ≥1 acre (statewide Construction General Permit 2022-0057-DWQ) | - |
| Permitting office | Hesperia Engineering Department, 9700 Seventh Ave, (760) 947-1000 | - |
| MS4 Permit | - | Santa Ana Region Order R8-2010-0036, NPDES CAS618036 |
| Construction permit threshold | - | ≥1 acre disturbed (Construction General Permit) |
| Local code | - | Rialto Municipal Code Title 13 - Public Services |
| Priority concern | - | Perchlorate plume - heightened source control |
| State authority | - | Cal. Water Code §§13260, 13385 |
Highlighted rows indicate differences between cities.
Hesperia FAQ
Do I need a SWPPP for a single-family home?
Most single-family residential lots are under one acre and do not require a statewide Construction General Permit SWPPP, but the city's SWMP requires Erosion and Sediment Control Plans (ESCPs) and a stabilized construction entrance for residential builds. Larger residential subdivisions (≥1 acre of disturbed soil) require a SWPPP through the State Water Board's SMARTS system.
Who regulates stormwater in Hesperia?
Locally, the Hesperia Engineering Department administers the SWMP. Regionally, the Lahontan Regional Water Quality Control Board oversees compliance with the statewide Phase II MS4 General Permit (Order WQ 2013-0001-DWQ as amended).
Rialto FAQ
Do I need a permit to wash my driveway in Rialto?
Wash water cannot discharge to the storm drain. Use dry methods (sweeping) or capture and dispose of wash water to the sanitary sewer with permission. Untreated discharge of soap, oil, or sediment to the gutter is an illicit discharge under Title 13.
When do I need a SWPPP for construction?
Any project disturbing 1 acre or more (including smaller sites that are part of a larger common plan) must obtain coverage under the State Construction General Permit and maintain a SWPPP. Smaller sites in Rialto still need erosion and sediment BMPs under the city WQMP.
Can I drain my pool to the street?
Only if dechlorinated and pH-neutral, and only with prior approval. Generally Rialto requires pool water to be discharged to the sanitary sewer via an approved cleanout.
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