Protecting Public Health and the Environment.

Idaho Environmental Guide for Local Governments: Source Water

Source water is untreated water from streams, rivers, lakes, or aquifers (ground water) that is used to provide public drinking water and to supply private wells used for human consumption.

Source water assessments are reports written by DEQ that provide information on:

  • potential contaminant threats to public drinking water sources
  • areas that contribute to the source
  • likelihood of the source to become contaminated

Communities can use source water assessments to implement drinking water source protection plans, programs, and activities.

Source water protection is a process that enables communities to protect ground water and surface water supplies that serve as sources for drinking water. Source water protection consists of voluntary or regulatory programs and activities that are typically implemented at the local level by a broad spectrum of community groups, including government, private entities, and individuals. A source water protection plan is often developed by a community or a public water system to identify actions a community can implement to help prevent contamination of water that supplies its public water system.

Why Communties Should Care

Safe drinking water is fundamental for a healthy and economically vibrant community. Local governments play a primary role in protecting the community's drinking water supply. The Idaho Environmental Protection and Health Act (I.C. § 39-126) mandates that state and local governments incorporate policies from the Idaho Ground Water Quality Plan into their programs and authorizes and encourages cities, counties, and other political subdivisions to implement ground water quality protection policies within their jurisdictions.

The Idaho Local Land Use Planning Act (I.C. § 67-6537) requires local governing boards to consider the impact on ground water quality when amending, repealing, or adopting a comprehensive plan. A comprehensive plan should consider protection of source water because a sustainable supply of clean and reliable drinking water is needed for the economic vitality of a community.

Preventing contaminants from entering the water that supplies a public water system minimizes potential problems, such as increased health risks, expanded drinking water monitoring requirements, additional water treatment requirements, and expensive environmental cleanup activities.

In many cases, public drinking water systems are not operated by local governments and do not have the authority to protect drinking water sources. Therefore, municipal and county governments have the responsibility and legal authority to enact and enforce drinking water source protection measures.

What Communities Can Do

  • Prior to project approval, request that source water impacts from the project be determined and that the project specify whether any federal or state requirements apply.
  • Plan ahead. Local governments have authority to manage potential sources of source water contamination within their jurisdictions. They can protect drinking water sources by including ground water and source water protection as a component in their comprehensive plans. Local governments can also implement ordinances and regulations such as wellhead protection overlay zones, riparian buffers, storm water management ordinances, and land-use controls to protect source water areas. A model source water protection ordinance is available on the Association of Idaho Cities website. The intent of the model ordinance is to assist city and county governments in taking steps to protect public water sources.
  • Use DEQ source water assessments to:
    • implement broader drinking water source protection plans, programs, and activities to address current problems and prevent future threats to the quality of drinking water and
    • manage development of high-risk activities to minimize threats to source water through planning, zoning, best management practices, and land use decisions.
  • Develop a source water protection plan to guide protection activities the community will take and inform and educate the public.
  • Acquire the land surrounding the drinking water source or obtain restrictive easements to protect the source from potential contamination. Restrictive easements are agreements that protect against threats to source water from development or other land use. Consider implementing:
    • Homeowner and business education programs to provide information on such topics as how to properly apply fertilizer
    • Water conservation standards
    • Collection sites for used oil, pharmaceuticals, and household hazardous waste
    • Community and business stewardship programs
    • Ground water protection policies and ordinances
    • Best management practices to mitigate the risk of potential contamination
  • Research funding potential to replace septic systems with upgraded sewer systems.
  • Request CAFO siting evaluations.
  • Identify groups in the community working on water issues, such as utility companies, water quality agencies, or advocacy organizations, and explore ways to collaborate.
  • Identify practices that threaten to pollute drinking water sources. Set up a task force of stakeholders, including citizens, to assess issues affecting source water protection areas.
  • Local governments have the authority to protect source water beyond federal and state laws and regulations. Determine what is best for the health and welfare of the community.

Staff Contacts

Source Water Coordinator
Rachael Smith
DEQ State Office
Water Quality Division
1410 N. Hilton
Boise, ID 83706
(208) 373-0249

Ground Water Coordinator
Kathryn Elliott
DEQ State Office
Water Quality Division
1410 N. Hilton
Boise, ID 83706
(208) 373-0191

DEQ Resources

Idaho Ground Water Quality Plan

Idaho's Source Water Protection Program

Funding Opportunities


Source Water Protection Grants

319 Grants

EPA Funding

EPA Source Water Protection Local Government Resources

Related Pages

Source Water in Idaho

Source Water Protection in Idaho

Source Water Assessments in Idaho

Ground Water in Idaho