Low Impact Development (LID)
Placer County is subject to the mandates for stormwater discharges as part of the Small Municipal Separate Storm Sewer Systems (MS4), Phase II of the National Pollution Discharge Elimination System (NPDES) small municipal stormwater program (State General Permit Number CAS0000004). This program, which is part of the Federal Clean Water Act, requires the County to regulate all projects that create and/or replace more than 2,500 square feet of impervious surface.
The goal of the West and East Placer Design Manuals is to provide standards for conformance to the permit requirements. The Design Manuals also provide hydromodification management standards. In addition, the West Placer Design Manual achieves the objectives of the Placer County Conservation Plan (PCCP).
The West and East Placer Storm Water Quality Design Manuals are available for download below.
The County is also developing an Aquatic Resource Program (CARP) that will streamline permitting processes within a stream system. Low impact development is critical for PCCP/CARP implementation to ensure Clean Water Act permit requirements are satisfied.
Frequently Asked Questions
Q: What is LID?
A: LID, or low-impact development, refers to an approach to stormwater management that improves water quality by reducing the amount of pollution from stormwater that enters our creeks and rivers. It can also be referred to as a Post Construction Best Management Practice (BMP). Impervious surfaces like parking lots and buildings impair our streams by increasing the amount of stormwater runoff that enters waterways. This runoff includes car oil, litter, gasoline, and other contaminants. The increased runoff further impairs waterways by contributing to erosion, stream incision, and sedimentation. Water quality and habitat for aquatic life is ultimately compromised. The term used to describe how development increases runoff is called “hydromodification.” By ensuring future development is constructed in a manner that reduces these impacts, water quality can be improved.
Q: What are some examples of LID practices?
A: Green roofs, permeable pavement, rain gardens, bio-retention swells, reducing and disconnecting impervious surfaces are all examples of LID practices.
Q: How is LID good for my community?
A: LID has multiple benefits for municipalities, developers, property owners, and the environment. LID improves water and air quality, encourages groundwater recharge, reduces stormwater management, and balances growth needs with environmental protection.
Rain gardens capture stormwater and allow for infiltration
Green roofs absorb stormwater and provide additional insulation
Vegetated basin at Northstar is a great local example of LID
Local Watershed Groups
Save Auburn Ravine Salmon and Steelhead
Dry Creek Conservancy
Friends of the River
American River Conservancy
North Fork American River Alliance
Protect American River Canyons
Save the American River Association
Foothills Water Network
Truckee River Watershed Council
For more information on the Placer LID Manuals, contact:
(email) or by phone: 530-745-7538