Stormwater runoff is generated when precipitation from rain and snowmelt flows over land or impervious surfaces (such as building roofs and paved surfaces) and does not infiltrate into the ground. Everyday activities such as driving, lawn and vehicle maintenance, and even walking your pet often cover surfaces with harmful materials. As the runoff flows over surfaces, it accumulates debris, nutrients, chemicals, sediment, or other pollutants that adversely affect water quality if the runoff is directly discharged untreated into nearby water bodies. In addition to stormwater quality concerns, increased impervious areas can cause flooding in urban and suburban areas. As more impervious surfaces are built, the volume and velocity of runoff also increase.

Possible negative impacts of stormwater runoff include:

• Flooding – Increased volumes of stormwater can lead to damage of public and private property and can threaten public safety by flooding roadways.
• Erosion – Higher stormwater velocities can cause bare ground and stream banks to erode causing sediment filled waterways and widened stream channels resulting in fish kills and loss of valuable property.
• Aesthetics – Stormwater pollution can cause dirty water filled with trash, debris, or harmful chemicals and sometimes can cause unpleasant odors.
• Fish and Aquatic Life – Polluted waters can kill fish and aquatic animals or contaminate the fish that we eat.
• Economic and Recreational Impacts – Impairments to waterbodies often effects fisheries, tourism, and recreation related businesses as well as recreational uses of waterbodies for swimming, fishing, and boating.
• Drinking Water - Stormwater pollution can increase the cost to treat water resources to provide safe drinking water. This cost increase typically results in higher prices for customers.

The primary method to control stormwater discharges and runoff is the use of best management practices (BMPs), pollution prevention activities, and habitat/wetland preservation or restoration. Click here for Information on How You Can Do Your Part and visit Create A Clean Water Future to learn more about stormwater pollution from activities such as lawn maintenance and car washing. For construction and post construction BMPs, please reference the Alabama Handbook for Erosion Control and Sediment Control and Stormwater Management.

Madison County is required by the Alabama Department of Environmental Management (ADEM) and the United States Environmental Protection Agency (EPA) to operate under a general NPDES permit and implement a Stormwater Management Program (SWMP) to reduce the contamination of runoff within its stormwater management area to the maximum extent practicable. 

Please see the following documents and links associated with Stormwater Management in Madison County:

Madison County NPDES General Permit (PDF)

Madison County Stormwater Management Program Plan (SWMPP) (PDF)

Madison County 2020/2021 Annual Report (PDF)

Madison County 2021/2022 Annual Report (PDF)

Madison County 2022/2023 Annual Report (PDF)

Madison County 2023/2024 Annual Report (PDF)

Madison County 2024/2025 Annual Report (PDF)

Boarding MS4 Programs

City of Huntsville Stormwater Management Program (Link)

City of Madison Stormwater Management Program (Link)

ALDOT MS4 Stormwater Management Program (Link)

The Clean Water Act and EPA regulations require construction site operators to obtain a NPDES permit to regulate land disturbance and stormwater discharges. ADEM established General NPDES Permit No. ALR100000 for discharges associated with construction activities. Construction projects that will disturb one or more acre of land disturbance or will disturb less than one acre but is part of a development or sale equal to or greater than one acre is required to operate under this permit.

Click here for guidance to Determine If Your Construction Site Needs a Stormwater Permit or visit ADEM’s website for more information.