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    County of Santa Clara

    Santa Clara Stormwater Laws & Regulations

    The County of Santa Clara has enacted a Stormwater Ordinance in order to establish minimum stormwater management requirements and controls to protect and safeguard the general health, safety, and welfare of the public residing in watersheds within this jurisdiction.  The County of Santa Clara  is the permitting authority for all land disturbing activities and requires the land owner to maintain all on-site stormwater control facilities and all open space areas (e.g. parks or “green” areas) required by the approved stormwater control plan. The County of Santa Clara will only provide construction permits to projects that establish a plan to manage stormwater runoff occurring during the construction process. The County of Santa Clara, under the NPDES program, also has the authority to inspect properties for noncompliance and can issue a notice of violation (NOV) for any deficiency or infraction onsite. Property owners are responsible for the maintenance of any stormwater facilities or practices located on the property. The County of Santa Clara has the authority to inspect stormwater facilities and practices in order to ascertain that they are properly maintained and functioning.

    Excerpt-C.3 Stormwater Handbook

    1.1 Purpose of this Handbook

    This handbook was written to help developers, builders, and project applicants include appropriate post-construction stormwater controls in their projects, to meet local municipal requirements and requirements of the Bay Area Municipal Regional Stormwater Permit (MRP). Municipalities covered by the MRP must require postconstruction stormwater controls on development projects as part of their obligations under Provision C.3 of the MRP. This permit is a National Pollutant Discharge Elimination System (NPDES) permit issued by the San Francisco Bay Regional Water Quality Control Board (Regional Water Board), allowing municipal stormwater systems to discharge stormwater to local creeks, San Francisco Bay, and other water bodies if municipalities conduct prescribed actions to control pollutants. In case of conflicting information between this handbook and the MRP, the MRP requirements prevail.

    The term “post-construction stormwater control” refers to permanent features included in a development project to reduce pollutants in stormwater and/or erosive flows during the life of the project – after construction is completed. The term “post-construction stormwater control” encompasses low-impact development (LID) site design, source control, and treatment measures as well as hydromodification management measures. LID techniques reduce water quality impacts by preserving and recreating natural landscape features, minimizing imperviousness, maximizing opportunities for infiltration and evapotranspiration, and using stormwater as a resource.

    Post-construction stormwater controls are required for both private and public projects. Although this handbook is written primarily for sponsors of private development projects, its technical guidance also applies to publicly-sponsored projects. Municipalities may also find the handbook useful for training municipal staff and consulting plan checkers.

    It’s important to note that post-construction stormwater design requirements are complex and technical: most projects will require the assistance of a qualified civil engineer, architect, landscape architect, and/or geotechnical engineer.

    8.1 Summary of O&M Requirements

    Maintenance is essential for assuring that stormwater treatment and hydromodification management (HM) measures continue to function effectively and do not cause flooding, provide habitat for mosquitoes, or otherwise become a nuisance. The maintenance requirements described in this chapter apply to regulated projects with stormwater treatment measures, including areas of pervious pavement, if any, and HM measures included in your project. The operation and maintenance (O&M) process can be organized into five phases, as described below:

    • Determining ownership and maintenance responsibility;
    • Identifying maintenance requirements when selecting treatment measures;
    • Preparing the maintenance plan and other documentation;
    • Executing a maintenance agreement or other maintenance assurance; and
    • Ongoing inspections and maintenance.
    8.1.1. Responsibility for Maintenance

    The responsibility for the maintenance of stormwater treatment and structural HM measures belongs to the project applicant and/or property owner unless other specific arrangements have been made. Ownership and maintenance responsibility for stormwater treatment measures and HM measures should be considered at the earliest stages of project planning. The municipal stormwater permit also requires that the project applicant provide a signed statement accepting responsibility for maintenance until this responsibility is legally transferred, as well as ensuring access to municipal, Water Board, and Santa Clara County Vector Control District staff.

    Excerpt- Post-Construction Urban Runoff Management

    Council Policy

    Operation and maintenance

    All post-construction treatment measures must be installed as specified on approved construction plans. Treatment measures shall be operated and maintained by qualified personnel consistent with approved development plans and/or supplemental operation and maintenance plans. Property owners must ensure that treatment measures continue to operate effectively for the life of the project. Property owners and/or property managers designated by the owner must keep a maintenance schedule and record of all treatment measures maintenance activities. Copies of maintenance schedules and records will be retained and made available for inspection upon request by the City.

    When used, all proprietary treatment measures must be operated and maintained per the manufacturers’ specifications. The City may require additional maintenance beyond the manufacturers' specifications, if needed.


    The Federal Clean Water Act requires the City of San José to operate under a Municipal Stormwater NPDES Permit for the discharge of stormwater via the City’s stormwater collection system. On October 14, 2009, the Regional Water Control Board adopted the Municipal Regional Stormwater NPDES Permit (Permit Number CAS612008) for the San Francisco Bay Region. In an effort to standardize stormwater management requirements throughout the nine county region, this permit replaces the formerly separate countywide municipal stormwater permits with a regional permit for 76 Bay Area municipalities, including the City of San José.

    The Municipal Regional Permit mandates the City of San José to use its planning and development review authority to require that stormwater management measures such as Site Design, Pollutant Source Control and Treatment measures are included in new and redevelopment projects to minimize and properly treat stormwater runoff. The MRP requires use of Low Impact Development (LID) techniques including infiltration, harvest and reuse, evapotranspiration, or biotreatment to manage stormwater. The objective of LID is to maintain predevelopment rates of infiltration, evaporation, and runoff from the property being developed. Treating stormwater as a resource, rather than a waste product is a central tenet of the MRP’s LID requirements.

    City Council Policy 8-14: Post-Construction Hydromodification Management (last revised February 23, 2010), is a related companion policy that addresses the management of stormwater runoff to minimize erosion and sedimentation in local rivers and creeks.

    Supplemental Documents:

    County of Santa Clara Stormwater Management Page

    Santa Clara C.3 Stormwater Handbook Guidance for Implementing Stormwater Requirements for New Development and Redevelopment Projects

    State of California Documents:

    California Stormwater Website

    Stormwater Multiple Application and Report Tracking System (SMARTS) Login