Project Clean Water

A water quality resource for the San Diego Region

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Project Clean Water was initiated in July 2000 to provide a broad and inclusive forum for exploring water quality issues of regional significance. Much of the focus during our first two years was on establishing a visible forum to discuss issues of shared concern, to find consensus solutions to priority problems, and to characterize baseline conditions in the region’s watersheds. This work was primarily carried out by Technical Advisory Committees (TACs) and numerous, ad hoc technical workgroups. Annual Clean Water Summits, a focal point of stakeholder participation, have provided an important opportunity to explore the issue of the day and validate and fine-tune the priorities and directions of Project Clean Water working bodies.

In response to input provided by participants, organizational changes were put into place in 2004 to streamline the overall Project Clean Water process and to focus more closely on the issues of greatest interest to stakeholders. Through discussion that occurred at the Watershed Protection TAC, the County of San Diego, the San Diego County Water Authority and the City of San Diego Water Department agreed to form a Regional Water Management Group (RWMG) which was needed to fund and develop an Integrated Regional Water Management Plan for the San Diego Region. The Watershed Protection TAC became the first stakeholder group supporting the development of this Plan.

Today, Project Clean Water serves as a resource both to government agencies and to the general public. In 2013, the San Diego Regional Water Quality Control Board (RWQCB) issued an updated National Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm and Sewer System (MS4) Permit Order No. R9-2013-0001 (as amended by Order Nos. R9-2015-0001 and R9-2015-0100), which requires those agencies operating under the permit to create and maintain a Regional Clearinghouse that provides the public with information regarding area water quality and efforts to protect it. This information was made accessible via Project Clean Water, which allows for additional cooperation and coordination between Copermittees to supplement and enhance water quality outcomes.


The plan for the protection of water quality prepared by the Regional Water Quality Control Board in response to the Porter-Cologne Water Quality Control Act.

Permittees to the National Pollution Discharge Elimination System (NPDES) Permit; each copermittee owns or operates an MS4, through which it discharges storm water and non-storm water into waters of the U.S. within the San Diego Region. Also sometimes referred to as Responsible Agency (RA) or Responsible Party (RP).

  • The populations of different species that live together, interacting with one another and with the chemical and physical factors that make up its nonliving environment. All ecosystems are connected.
  • The chemical and physical factors include sunlight, rainfall, soil nutrients, climate, etc.
  • Example: Ecologists studying a lake or stream ecosystem focus on how benthic plants, macro invertebrates, fish, etc affect each other and how the environment affects them.

A classification embracing one of the following features which are defined by surface drainage divides: (1) in general, the total watershed area, including water-bearing and nonwater-bearing formations, such as the total drainage area of the San Diego River Valley; and (2) in coastal areas, two or more small contiguous watersheds having similar hydrologic characteristics, each watershed being directly tributary to the ocean and all watersheds emanating from one mountain body located immediately adjacent to the ocean.

These permits pertain to the discharge of waste to surface waters only. All State and Federal NPDES permits are also waste discharge requirements.

  • A creek, river, lake, ocean or other waterway into which tributaries, stormwater, runoff and other material flows.
  • Surface runoff and drainage that comes from rain and other forms of precipitation.
  • Stormwater management: Policies and procedures for handling stormwater in acceptable ways to reduce the problems of flooding, reduce or prevent pollution picked up and carried by runoff, and reduce the erosion of stream banks.
  • A government standard that gives the maximum amount of a particular pollutant released daily into a creek, river or other body of water without harming the health of the water body.

Typically coincides with a hydrologic unit; the exception is San Diego Bay, which consists of three unique hydrologic units: Pueblo, Sweetwater, and Otay.

  • Using water wisely without wasting it.
  • Examples: taking shorter showers; installing low-flow shower heads, toilets, washers and dishwashers; turning off running water while brushing teeth, washing the car, and washing the dishes; watering landscapes carefully; etc.
  • The uses of water, which are necessary for the survival and well being of humans, plants, and wildlife.
  • Examples: power generation; recreation; aesthetic enjoyment; navigation; domestic, municipal, agricultural and industrial supply; and preservation and enhancement of fish, wildlife, and other aquatic resources or preserves.
  • Noun: The water or other fluid (including any solid and dissolved material), that directly or indirectly enters into stormwater drainage or receiving waters.
  • Example: Water that picks up and carries sediment and trash as it is released to the ground from swimming pool draining.
  • Verb: To allow pollutants to directly or indirectly enter into stormwater drainage or receiving waters.
  • Water that sinks into the soil and is stored in slowly flowing and slowly renewed underground reservoirs called aquifers.
  • Ground areas or covered areas into which rainfall cannot effectively infiltrate, or soak in.
  • Examples: Impervious surfaces may be natural, such as a clay layer in soil, or man-made, such as rooftops, roads, sidewalks, parking areas and concrete channels.
  • Land that has little or no development (few man-made structures) and with mostly natural or undisturbed conditions.
  • Examples: benefits often associated with open space include preserving water bodies, wetlands and riparian corridors, sensitive species habitat, recreation trails and parks, wildlife habitat and migration corridors, scenic vistas, agricultural land, and watershed recharge areas.
  • Water and other fluid that flows off of a property to surface streams, rivers and lakes.
  • Urban Runoff often comes from rain and many other sources and flows toward a storm drain, frequently located along curbs of parking lots and roadways. Once in the storm drain, it flows through pipes, which lead to an outfall where the stormwater directly enters a creek, river, lake or the ocean.
  • Examples: Fluids from the over watering of lawns, car washing, draining of pools, and the hosing off of driveways and other constructed surfaces.
  • Rural Runoff often comes from storm events and agricultural activities and flows off land into drainage ditches, culverts and open flood channels and/or directly enters a stream, creek, river, lake, lagoon, bay or the ocean.
  • Examples: Fluids from the over-watering of croplands and other farm or ranch landscapes and runoff from ranch animal care and machinery cleaning.
  • A measure of how poisonous a substance is.
  • Water used by homes, businesses, agriculture and other industries and that contains unwanted materials (wastes).
  • Examples: Fluids that come from bathroom and kitchen drains, restaurant sinks, etc. These drains lead to underground pipes that connect to a wastewater treatment plant or septic system.
  • Any channel for water. A waterway may be man-made or natural.

Numerical or narrative limits on constituents or characteristics of water designed to protect designated beneficial uses of the water.

  • Activities done to prevent or reduce the discharge of pollutants to stormwater, the stormwater drainage system or receiving waters.
  • Examples: good housekeeping practices like sweeping up litter, picking up pet waste, recycling, composting; education; treatment practices; practices to control or prevent runoff, spills or leaks; water conservation; erosion control; and proper disposal of wastes and leftover materials.
  • Partially enclosed coastal area at the mouth of a river where its fresh water, carrying fertile silt and runoff from the land, mixes with salty seawater.
  • Examples: Tijuana Estuary, Los Penasquitos Lagoon, San Dieguito Lagoon, Agua Hedionda Lagoon, Batiquitos Lagoon, San Elijo Lagoon, Santa Margarita Lagoon

A major logical subdivision of a hydrologic unit which includes both water-bearing and nonwater-bearing formations.

A municipally-owned storm sewer system regulated under the Phase I or Phase II storm water program implemented in compliance with Clean Water Act section 402(p). Note that an MS4 program’s boundaries are not necessarily congruent with the permittee’s political boundaries.

A chemical or biological substance in a form that can be incorporated into, onto, or be ingested by and that harms aquatic organisms, consumers of aquatic organisms, or users of the aquatic environment.

  • A system of catch basins and pipes that carries urban runoff from buildings and land surfaces to receiving waters. Also known as a “storm sewer”. The purpose of a storm drain is to minimize flooding.
  • Examples: Constructed openings in roads and street gutters connected to underground pipes that lead directly to the ocean.
  • A measure of how clear water is. Particles (like dirt, algae, and decaying waste) cause water to be cloudy. When light passes through this cloudy water, the light hits the particles and can’t shine through – the light scatters. The amount of light that scatters can be measured to tell us how “turbid” a water sample is.
  • Turbidity affects fish and other aquatic life by: 1) limiting photosynthesis and increasing respiration, which increases oxygen use, and the amount of carbon dioxide produced; 2) clogging fish gills and the feeding apparatus of bottom-dwelling animals by suspended particles; and/or 3) blocking the vision of fish as they hunt food and smothering bottom-dwelling animals.
  • A place where water is cleaned or “treated” so that it can be safely used or returned to the environment.

Refers to chemical, physical, biological, bacteriological, radiological, and other properties and characteristics of water which affect its use.

As defined in either the San Diego Regional Basin Plan or Order No. R9-2013-0001, as amended by Order Nos. R9-2015-0001 and R9-2015-0100.