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What is Stormwater?

Stormwater is a valuable resource where we live and work. Before our landscape was developed, rain water landed on trees and vegetation, where it was absorbed by plants and soils, as well as local creeks and rivers. Through this process, groundwater recharged and the water was cleaned by percolating through layers of soil and rock.

Today, that same rainwater hits impermeable surfaces like roofs, concrete walkways and asphalt roads where it is guided to our storm drain system. This rain water moves faster, causing erosion and flooding, and picks up all kinds of trash and pollutants along the way. Stormwater management is not just about preventing pollution, but also about changing the way we build our community to reconnect this valuable resource to our local landscapes. 

Why is Stormwater Runoff a Concern?

Water from storms picks up debris, chemicals, dirt and other pollutants; and flows directly to our local waters. These waters contribute to our watershed.

Our watershed stretches from the snowy Sierra Nevada mountaintops, down the foothills and through the valley into the Delta and then to the San Francisco Bay, and eventually the Pacific Ocean. Along the way, pollution and trash from the water impacts wildlife and drinking water quality.

But, small changes on your part can make a huge difference in protecting our watershed. 

What are the Effects of Stormwater Pollution?

  1. Polluted stormwater runoff hurts plants, fish, animals and people.
  2. Polluted stormwater affects drinking water sources. This, in turn, affects human health and increases drinking water treatment cost.
  3. Sediment clouds water bodies and that makes it difficult for aquatic plants to grow.
  4. Excess nutrients cause algae blooms. When algae die, they sink to the bottom and decompose in a process that removes oxygen from the water. Fish and other aquatic organisms can’t exist in water with low dissolved oxygen levels.
  5. Bacteria and other pathogens wash into swimming areas and create health hazards.
  6. Debris – including plastic bags, six-pack rings, bottles, and cigarette butts, lids and bottle caps – washed into water bodies choke, suffocate or disable aquatic life.
  7. Household hazardous wastes (insecticides, pesticides, paint, solvents, used motor oil) poison aquatic life.
  8. Land animals and people become sick or die from eating diseased fish and shellfish or ingesting polluted water.

What is the Difference between the Storm Drain System and the Sanitary Sewer System?

Every time you use the shower, sink or toilet, the water goes through Sacramento Regional County Sanitation District waste-water facility. This water goes through a number of wastewater treatment processes so that only cleaned water enters the waterways.

However, water that passes through the storm drain system remains completely untreated! The water that flows through the storm drain system carries pollutants (e.g. pesticides, fertilizers, litter) directly into the Sacramento River and the Deep Water Ship Channel.


What is an MS4 Permit?

The MS4 Permit requires that the City manage stormwater impacts from a variety of sources, including illicit discharges, construction projects, litter, residential irrigation runoff, pool draining, commercial kitchens and manufacturing facilities. The City also helps prevent stormwater pollution through education, outreach, business and residential support; and by managing municipal operations and sites effectively. For more information or help with stormwater protection, please call the Environmental Services Department at (916) 617-4590.


On February 5, 2013, the State Water Resources Control Board (State) adopted the Phase II Small Municipal Separate Storm Sewer System (MS4) National Pollutant Discharge Elimination System (NPDES) Permit, Water Quality Order No. 2013-0001-DWQ, General Permit No. CAS000004 (Phase II Stormwater Permit). The effective date of the permit was July 1, 2013, with the requirements phased in over the five-year permit term. The Phase II Stormwater Permit regulates discharges from Small MS4s and requires Permittees to implement a stormwater management program. The City of West Sacramento is named as a Small MS4 Permittee in the Phase II Stormwater Permit and implements its stormwater management program locally to prevent and eliminate stormwater pollution to the maximum extent practicable.

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