Regulatory compliance with the EPA requires Strafford County to make their “Stormwater Management Program” (SWMP) publicly noticed. In addition, links to a number of informative bulletins from the NH Department of Environmental Services (NHDES) that cover best management practices for Stormwater Management are included for further reading as part of the County’s educational outreach.



Stormwater is water from rain or melting snow that does not soak into the ground. In a forest, meadow, or other natural environment, stormwater usually soaks into the ground and is naturally filtered. When forests and meadows are developed, they are commonly replaced with impervious surfaces such as houses, buildings, roads and parking lots. Impervious surfaces prevent stormwater from soaking into the ground, which create excess stormwater runoff.    

Excess stormwater runoff can create problems when stream channels have to accommodate more flow than nature intended. When this happens, flooding is more frequent, banks erode, and the groundwater table is lowered. Stormwater can also become polluted with trash and debris, vehicle fluids, pesticides and fertilizers, pet waste, sediment, road salt and other pollutants when it flows over impervious surfaces, lawns, and other developed areas. These pollutants get picked up with the stormwater runoff and eventually flow untreated into nearby lakes, streams and other bodies of water.  The end result is to render these recreational and wildlife areas unsafe for swimming and creating an unsafe habitat for fish and other wildlife.

Stormwater pollution is one of the leading causes of water pollution nationally. Unlike pollution from industry or sewage treatment facilities, i.e., point source pollution, which is caused by a discrete number of sources that are easily identified, stormwater pollution is caused by the daily activities of people everywhere.

In New Hampshire, stormwater has been identified as contributing to over 90% of the surface water quality impairments in the state. All across New Hampshire, communities, businesses and property owners are experiencing the challenge of managing stormwater to protect the state’s water resources and to balance the need for a healthy environment with the need for social and economic growth.



Excessive stormwater runoff can carry pollutants to receiving waters that impact a wide range of water quality issues including:

- Shellfish bed closures due to bacterial contamination.
- Swimming beach closures due to bacterial contamination.
- Pathogenic bacteria/viruses from fecal material in pet waste.
- Toxic cyanobacterial algal growth from excess nutrients in runoff.
- Toxicity from ammonia, metals, organic compounds, pesticides, and other contaminants.
- Depleted dissolved oxygen levels due to increased oxygen demand from biodegradable organic
  material – leading to oxygen deprivation of aquatic organisms.
- Contamination of groundwater aquifers with soluble organic chemicals, metals, nitrates, and salt.



Strafford County Separate Storm Sewer Systems (MS4) Permit Year 2 Plans
Illicit Discharge Detection and Elimination (IDDE) Plan 2020
Stormwater Management Program (SWMP) 2020
New Hampshire Small MS4 General Permit Annual Report 2020

Strafford County NPDES Permit Approval
National Pollutant Discharge Elimination System (NPDES) Permit Approval – 2019

Strafford County Separate Storm Sewer Systems (MS4) Permit Year 1 Plans
Illicit Discharge Detection and Elimination (IDDE) Plan 2019 
Stormwater Management Program (SWMP) 2019
New Hampshire Small MS4 General Permit Annual Report 2019



Virtually all water pollution problems in New Hampshire are caused by stormwater runoff from the roads we travel, the buildings and parking lots we visit, and even the homes in which we live. Every single property has the potential to contribute to water pollution. Every property owner can also be part of the solution to water pollution. NHDES has created a comprehensive guidance document and a hands-on voluntary program to assist New Hampshire home and small business owners in reducing water pollution.

New Hampshire Homeowner’s Guide to Stormwater Management



City of Dover link on managing Pet Waste
Managing septic systems 
Full NHDES “Stormwater” website with links