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Construction Site Requirements


Sediment is one of the major pollutants in stormwater runoff. Sediment loads from construction sites can be 80 to 100 times higher than from undisturbed lands. Sediment can clog storm drains or catch basins, which may lead to street flooding or reduced infiltration from dry wells. Additionally, increased sediment in our rivers and lakes can damage plant and wildlife habitat. Sediment is not the only pollutant found at construction sites. Other construction site wastes, such as cement, paint, oil, fuel, or construction debris also contribute to stormwater pollution.

In accordance with its permit requirements to reduce construction site stormwater pollution, Maricopa County has enacted the Stormwater Quality Management and Discharge Control Regulation. This regulation requires an owner or operator who intends to disturb an area of land that is equal to or greater than one acre, or that is less than one acre but is part of a larger plan of development to obtain approval from the Maricopa County Environmental Services Department prior to any disturbance of the site. The Stormwater Site Plan must consider possible water quality impacts and the best management practices (BMPs) that will be utilized to minimize erosion, reduce sediment transport, and control other wastes. For submittal requirements and applicable fees, please refer to the Forms/Applications page or the Fee Schedule




Do I need a stormwater approval from Maricopa County for my project?

  1. Will your project disturb one or more acres or is part of a larger plan of development?
  2. Is your project within the unincorporated urbanized area of Maricopa County?
    1. To determine if you project is within the unincorporated urbanized area of the County, follow these instructions:
      1. Click on the link to PlanNet to bring up the Map Viewer
      2. In the Map Viewer, under the “Communities” layer, select “Cities and Towns” to make visible on the map
      3. Under the “Demographics” layer, select “Urbanized Unincorporated Areas” to make visible on the map
      4. The white areas with blue cross-hatching are the urbanized, unincorporated areas
      5. Search by Parcel or Address to determine if your project is within the urbanized unincorporated areas

If you answered "Yes" to both questions, your project may need to obtain the approval of the Maricopa County Stormwater program prior to the start of construction. Please call our office at (602) 372-1569 for more information.

There are many resources for guidance in preparing a Stormwater Pollution Prevention Plan and potential BMPs. In addition to the links below, please visit our Resources page.

For more information on Maricopa County’s Stormwater Program, please E-mail us at mcesd.sw@mail.maricopa.gov or call (602) 506-5557.

For regulation related comments or questions, please e-mail us at participate@mail.maricopa.gov