401 Water Quality Certification and Waste Discharge Requirements Program
Wetland and Riparian Area Protection
The Clean Water Act (CWA) Section 401 Certification and Waste Discharge Requirements Program for dredge and fill activities is an important tool for regulating hydrologic modification projects in addition to other projects which involve dredge and fill.
- Decisions Pending
- Descanso Gardens, Nature Discovery Garden and Lake Improvements Project
- Newhall Land and Farming Company, Entrada South Development Project
- RV DEV, LLC, Royal Vista Residential Development Project
- Applications for Clean Water Act Section 401 Water Quality Certifications
- Public Notices
- Water Quality Certification Actions Recently Issued
Updated: August 28, 2026
- Hydromodification and California Wetlands
Contact Information
General Email (Include in all communications)
RB4-401Certification@waterboards.ca.gov
Aditya Sood
(213) 576-6774
Supervisor, Wetland and Riparian Protection Unit
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Staff
Ariana Chavez
(213) 620-6367
Scientific AidLibby Lee
(213) 576-6705
Engineering GeologistChloe Seifert
(213)576-6617
Environmental ScientistSnejana Toneva
(213) 576-7159
Engineering GeologistPansy Yuen
(213) 576-6622
Engineering Geologist
