New Development and Redevelopment

Natural landscapes filter & recycle stormwater. Impervious development causes high volumes of stormwater to “run off” into urban storm drains & creeks (Adapted from US EPA)

Urban development traditionally involves replacing natural landscapes with impervious areas, such as roofs, pavements, streets, and storm drain systems, causing greater amounts of polluted stormwater runoff to flow directly into creeks.

The impact of urban development on waterways can be reduced by using Low Impact Development (LID) techniques. LID techniques reduce runoff and mimic a site’s natural (predevelopment) hydrology by minimizing disturbed areas and impervious surfaces, and retaining and treating stormwater runoff using infiltration, evapotranspiration, rainwater harvesting and use, or biotreatment.

Private and public new and redevelopment projects that create or replace amounts of impervious surface that exceed certain thresholds are required to include appropriate site design, pollutant source control, treatment measures, and where appropriate, hydromodification management measures that improve, protect and treat urban runoff. Local municipalities have developed Green Stormwater Infrastructure (GSI) Plans for incorporating LID features into public lands, such as streets, buildings, parking lots, and parks.

Key Guidance Documents

SCVURPPP C.3 Stormwater Handbook
Provision C.3 Data Form
Special Projects Worksheet
C.3 Stormwater Treatment Measure Sizing Worksheets
Fact Sheets on New Stormwater Quality Control Requirements

Site Design Measures

Disconnected downspouts allow roof runoff to flow into landscaping (Photo by Program staff) Site design measures are site planning techniques that can help reduce the impacts of increased runoff and pollution from land development on water quality. Examples include preserving existing vegetation, reducing impervious surfaces, directing runoff to vegetated areas, using pervious pavement, and directing...

Pollutant Source Control Measures

Covered dumpster area (Photo by Program staff) Vehicle wash area with drain connected to sanitary sewer (Photo by Program staff) Source controls prevent potential pollutant sources from coming in contact with rainfall and runoff. Examples include: roofed trash enclosures, covered outdoor materials handling and storage areas, storm drain labeling, and sanitary sewer drains for vehicle...

Treatment Control Measures

Stormwater treatment measures are systems designed to remove pollutants from stormwater before it reaches the storm drain system. Examples of allowable treatment measures for most projects include: bioretention areas, flow-through planters, infiltration facilities (e.g., trenches, pervious pavements, or subsurface systems), and rainwater harvesting systems. Vault-based treatment systems are only allowed at certain high-density projects that...

Hydromodification Controls

Eroded creek filled with sediment (Photo by Program staff) When land is covered with buildings and pavement, runoff enters creeks at higher rates and volumes, resulting in channel erosion, flooding and habitat loss. These changes in runoff characteristics are known as hydromodification. Hydromodification management measures are detention and/or infiltration facilities that are constructed with special...

New Development and Redevelopment Resources and Fact Sheets

SCVURPPP Qualified Consultant List SCVURPPP C.3. Stormwater Handbook DateTitleCategoriesTags11/12/2024SCVURPPP List of Qualified Consultants – November 12, 2024Other DocumentsNew Development (C.3.)10/28/2024C.3 Stormwater Handbook (October 2024)Guidance DocumentsNew Development (C.3.)9/19/2024Provision C.3 Data Form 2024FormsNew Development (C.3.)1/24/2024Sizing for Flow-Based Treatment MeasuresOther DocumentsNew Development (C.3.)1/24/2024Sizing for Flow and Volume-Based Treatment Measures (Combination Flow and Volume Approach)Other DocumentsNew Development (C.3.)1/24/2024Sizing for...

Operation & Maintenance

Maintenance is essential for assuring that stormwater treatment and hydromodification management measures continue to function effectively and do not cause flooding, provide habitat for mosquitoes, or otherwise become a nuisance. To ensure that property owners are maintaining treatment measures, Santa Clara Valley municipal agencies have inspection and reporting programs in-place. Property owners are required to...

New Development & Redevelopment Documents

Date	Title	Categories	Tags
11/12/2024	SCVURPPP List of Qualified Consultants – November 12, 2024	Other Documents	New Development (C.3.)
10/28/2024	C.3 Stormwater Handbook (October 2024)	Guidance Documents	New Development (C.3.)
9/19/2024	Provision C.3 Data Form 2024	Forms	New Development (C.3.)
1/24/2024	Sizing for Flow-Based Treatment Measures	Other Documents	New Development (C.3.)
1/24/2024	Sizing for Flow and Volume-Based Treatment Measures (Combination Flow and Volume Approach)	Other Documents	New Development (C.3.)
1/24/2024	Sizing for Volume-Based Treatment Measures Based on the Adapted CASQA Stormwater BMP Handbook Approach	Other Documents	New Development (C.3.)
12/21/2023	Special Projects Worksheet	Other Documents	New Development (C.3.)
6/30/2023	Green Stormwater Infrastructure Vegetation Guide	Other Documents, Uncategorized	Bioretention, GSI, New Development (C.3.)
4/25/2023	Annual C.3 Workshop – Addressing Stormwater Requirements in Development Project Plan Review – April 25, 2023	Workshops	New Development (C.3.)
4/19/2023	New Stormwater Control Requirements for Large Single-Family Home Development Fact Sheet	Fact Sheets	New Development (C.3.)
2/28/2023	Annual C.3 Workshop – Part 1: Green Stormwater Infrastructure in the Public Right-of-Way – Implementing New Requirements – February 28, 2023	Workshops	New Development (C.3.)
1/12/2023	Stormwater Quality Control Requirements – Information for Developers, Builders and Project Applicants, Effective July 1, 2023	Fact Sheets	New Development (C.3.)
1/12/2023	Update on Stormwater Treatment Requirements for New Development and Redevelopment Projects, Effective July 1, 2023	Fact Sheets	New Development (C.3.)
12/20/2022	SCVURPPP List of Qualified Consultants	Other Documents	New Development (C.3.)
6/9/2022	Annual C3 Workshop – June 9, 2022	Workshops	New Development (C.3.)
7/16/2021	New and Redevelopment Projects Litter Reduction Fact Sheet	Fact Sheets	New Development (C.3.), Trash, ZLI
7/1/2021	Biotreatment Soil Mix Verification Checklist (PDF Form)	Checklists	New Development (C.3.)
7/1/2021	Biotreatment Soil Media and Mulch Guidance	Guidance Documents	New Development (C.3.)
6/10/2021	Annual C.3 Workshop – Moving Forward with Green Stormwater Infrastructure Implementation	Workshops	New Development (C.3.)
10/29/2019	Annual C.3 Workshop – Installation and O&M Inspections of Stormwater Treatment Measures	Workshops	New Development (C.3.)
9/24/2019	Drainage Management Area Summary Table	Forms	New Development (C.3.)
9/1/2019	SCVURPPP Green Stormwater Infrastructure Handbook	Guidance Documents	GSI, New Development (C.3.)
12/4/2018	SWRP Public Meetings August 28 & September 6, 2018	Meeting Agendas, Presentations	New Development (C.3.)
11/29/2018	Workshop Materials – Stormwater Resource and Green Stormwater Infrastructure Planning: Opportunities for Multi-Benefit Projects in Santa Clara Valley – 11/29/18	Workshops	GSI, New Development (C.3.)
11/29/2018	Stormwater Resource and Green Stormwater Infrastructure Planning: Opportunities for Multi-Benefit Projects	Workshops	New Development (C.3.)
8/29/2018	GSI Handbook Workshop #2 – April 24, 2018	Workshops	GSI, New Development (C.3.)
8/29/2018	GSI Handbook Workshop #1 – April 10, 2018	Workshops	GSI, New Development (C.3.)
6/7/2017	Stormwater Control Measure Requirements for Development Projects – June 7 and 13, 2017	Workshops	New Development (C.3.)
4/19/2017	Green Infrastructure Design and Implementation Workshop – April 19, 2017	Workshops	GSI, New Development (C.3.)
1/23/2017	Stormwater Controls (C.3.h) Inspection Workshop – January 23 and 27, 2017	Workshops	New Development (C.3.)
9/1/2016	Integrating Green Infrastructure into Public Streets, Roads, Buildings, and Parking Lots (for elected officials)	Fact Sheets	New Development (C.3.)
9/1/2016	Greening Our Streets, Buildings, and Parking Lots (for general public)	Fact Sheets	New Development (C.3.)
6/20/2016	C.3 Stormwater Handbook (June 2016)	Reports	New Development (C.3.)
6/9/2016	Annual C.3 Workshop June 9, 2016	Workshops	New Development (C.3.)
6/1/2016	Biotreatment Soil Mix Supplier Certification Statement	Certification Statements	New Development (C.3.)
4/25/2016	Green Infrastructure Workshop – Series 1 – April 25, 2016	Workshops	New Development (C.3.)
4/18/2016	BASMAA Regional Biotreatment Soil Specification (2016)	Guidance Documents	New Development (C.3.)
6/16/2015	Annual C.3. Stormwater Workshop: “Low Impact Development and Green Infrastructure – What Will the Future Bring?” – June 16, 2015	Workshops	New Development (C.3.)
5/6/2015	C.3.h O&M Stormwater Inspection Compliance Workshop: Implementing the requirements in MRP Provision C.3.h – May 6, 2015	Workshops	New Development (C.3.)
6/4/2014	Annual C.3. Stormwater Workshop: Current Trends in Low Impact Development and Green Street Implementation – June 4, 2014	Workshops	New Development (C.3.)
4/8/2014	Biotreatment Soil Mix Research and Verification Guidance Development	Guidance Documents	New Development (C.3.)
4/8/2014	Guidance on Biotreatment Soil Mix Review and Approval Options	Guidance Documents	New Development (C.3.)
12/16/2013	Stormwater Treatment Facility Inspection Workshop – December 16, 2013	Workshops	New Development (C.3.)
11/1/2012	Rain Garden Fact Sheet	Fact Sheets	New Development (C.3.)
8/1/2012	Landscape Dispersion Fact Sheet	Fact Sheets	New Development (C.3.)
8/1/2012	Rain Barrel Fact Sheet	Fact Sheets	New Development (C.3.)
8/1/2012	Pervious Paving Fact Sheet	Fact Sheets	New Development (C.3.)
12/18/2010	Biotreatment Soil Mix Research and Verification Guidance Development	Guidance Documents	New Development (C.3.)
4/9/2009	HMP Cost Estimating Guidance	Guidance Documents	New Development (C.3.)
10/12/2006	Impervious Surface Area Thresholds for Control of Hyrdomodification: an Evaluation Using Data from The Santa Clara Basin	Reports	New Development (C.3.)
6/6/2006	Restricted content	Fact Sheets	Archive, New Development (C.3.)
4/21/2005	Hydromodification Management Plan Final Report	Reports	New Development (C.3.)
4/21/2005	Hydromodification Management Plan	Guidance Documents	New Development (C.3.)