Resource Management Agency Seal

Resource Management Agency

Environmental Services

Environmental Services
1441 Schilling Place
Salinas, CA 93901
(831) 755-4879
(831) 755-5877

Although every effort is made to provide complete and accurate information on this website and all its documents, users are advised to contact applicable County Resource Management Agency staff before making project decisions and fee estimates.

Stormwater Management

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Program Description:

The federal Clean Water Act mandates that any municipal, industrial or commercial facility that discharges storm water runoff must first obtain coverage under a National Pollutant Discharge Elimination System (NPDES) permit. In California, the State Water Regional Control Board (SWRCB) and the nine Regional Water Quality Control Boards have been given regulatory authority by the federal government to manage NPDES programs. In July 2013, the Central Coast Water Board adopted Order R3-2013-0032 with more stringent Post Construction Requirements (PCRs). The PCRs apply to projects located in the Urbanized Area that create or replace 2,500 square feet or more of impervious area.

Storm water can be defined as rain, snowmelt or any other precipitation event that flows over the land or any other surface. This runoff water will percolate into the ground, be absorbed by vegetation, evaporate or flow over the land into rivers, lakes and storm drains. As urban development and expansion becomes more prevalent, the amount of impermeable ground surfaces increase. Impermeable ground surfaces such as parking lots, sidewalks, roofs and compacted soils increases the amount of runoff into waterways and decreases the amount of water that slowly infiltrates back into the ground. The water runoff that flows over the impermeable ground surfaces can accumulate sediment, fertilizers, pesticides, gasoline, heavy metals, animal waste, litter, etc.; which if left untreated can diminish the quality of local waterways.


Post Construction Requirements:

The Post-Construction Requirements (PCRs) were adopted in July 2013 and will require projects located in the urbanized area to implement low impact development techniques. The goal of low impact development techniques is to better enable water to infiltrate into the soil before it becomes runoff. The PCRs emphasize protection and restoration of watersheds to promote sustainable relationships required for a watershed to be considered healthy.

What Projects Must Comply? :

Projects located in the urbanized area that receive their first discretionary approval after March 6, 2014, or ministerial projects (projects that do not require discretionary approval) that have been approved after March 6, 2014, are subject to the PCRs. The Stormwater Technical Guide, developed by the Monterey Regional Stormwater Management Program, can be used to determine which PCRs are applicable to your project.

Stormwater Control Plans:

  • Project type and description
  • Total new impervious area
  • Total replaced impervious area
  • Total pre-project impervious area
  • Total post-project impervious area
  • Net impervious area
  • Watershed Management Zone
  • Groundwater Basin (if applicable)

Watershed Management Zones:

The urbanized area of the Central Coast Region is categorized into 10 Watershed Management Zones (WMZs), based on common key watershed processes and receiving water type (creek, marine nearshore waters, lake, etc.). Identifying the WMZ that your project is located in will be necessary for projects that must implement Post Construction Requirement No. 3 Runoff Retention and Post Construction Requirement No. 4 Peak Management.(Map Link)

Groundwater Basins:

Groundwater Basins underlie some of the Watershed Management Zones (WMZs) in the urbanized area, but not all. Identifying the Groundwater Basin, if present, and Watershed Management Zone that your project is located in will be key in implementing applicable Post Construction Requirements (PCRs).

Rainfall Maps: