Iowa Source Water Protection Program

The term "Source Water" is used to define drinking water in its original environment, either as surface water (rivers, streams, reservoirs, lakes) or as groundwater (aquifers), before being withdrawn, treated, and distributed by a water system.  Source Water Protection (SWP) is the act of preventing contaminants from entering public drinking water sources.  

The quality of the source water can be influenced by both natural and human activities.  The concept of Source Water Protection is to manage the areas through which water travels and the activities that occur on the land, in order to protect the quality of the resource.  These protection efforts save the community money through improved water quality requiring less treatment, longer life cycle for a well, and less likelihood of having to seek an alternate source or replace the well due to contamination.  

Surface water is more susceptible to contamination incidents from natural or man-made causes, such as a flood or a chemical spill, but it also recovers much more quickly than does groundwater.  Groundwater is much less susceptible to contamination, but when that happens, natural recovery is very slow to occur.

Source Water Protection includes both groundwater (wellhead) protection and surface water protection.

The Iowa DNR SWP Program is a voluntary program, although there are numerous benefits for a water system to protect its water supply.

There are three components to the Source Water Protection Program.  

  1. The DNR provides the initial source water assessments, called Phase 1 assessments, to all community water supplies in Iowa.  This assessment details the water system's active wells, delineates the source water protection areas, susceptibility to contamination classification, and provides the known potential contamination sources.   
  2. In the second step, the system then develops its Source Water Protection Plan through a local team effort.  These plans are sometimes called Phase 2 plans. The components are listed in a templated plan that is used to guide the team through the process to determine how the system will protect its drinking water resource.  
  3. In the third step, the SWP Plan that has been developed is implemented, addressing the specific items that the system will use to protect its drinking water resource.

The development of a good SWP Plan doesn't require any assistance or involvement of an engineer or consultant.  A system may wish to contact an outside entity for assistance.  The Conservation Districts of Iowa and the Iowa Rural Water Association provide experienced source water consultation and assistance for developing the SWP Plan, at no charge to the public water supply.  The Iowa Association of Municipal Utilities may also provide assistance with certain aspects of the SWP Plan.

Targeted Community Water Supplies
The Source Water Protection Program for Targeted Community Water Supplies works with communities in need of addressing an existing contaminant problem in their drinking water supply. 

A "targeted" community is defined as:

  • Has identified a contaminant(s) that is trending upwardCity of Elliott
  • Nitrates above 5 mg/L and trending upward
  • Shallow alluvial wells that are highly susceptible
  • A willing community with willing stakeholders 

This program offers to: 

  1. Assist in developing a SWP Community Planning Team, who are locally driven.
  2. Coordinates with IDNR’s Contaminated Sites Section staff to conduct a groundwater site investigation to determine if contaminant of concern is derived from point source or non-point source and determine groundwater flow path
  3. Assists the local planning team in identifying practices that will effectively decrease risk
  4. Assists local planning team in identifying resources for SWP practice implementation
  5. Supports grant applications for SWP project implementation
  6. Assists in evaluating implementation results over time
Source Water Applications
Source Water Tracker - Searchable database that houses SWP Plans, Phase 1 assessments, groundwater investigations, system contact information, and other SWP efforts that communities have gone through to protect their drinking water. 

Source Water Mapper - Searchable database designed to depict spatially an online version of the community's Phase 1 assessment, including an inventory of wells and contaminants. It lists most major programs and contaminants, with detailed location information and links to existing databases.
Additional Links

The following presentations, Geographic Information System (GIS) data, and handouts were made available at previously held Iowa Source Water-GIS Training sessions.

All GIS data used in the training can be found in the links below:

Additional GIS Resources:
Non-Targeted Community Water Supplies

Wellhead Protection

The Source Water Protection Program for Non-Targeted Community Water Supplies works with all communities in Iowa that are interested in Source Water Protection.  This program:

  1. Provides initial Source Water Assessment Reports (Phase 1) for municipal water supplies
  2. Updates municipal well information for communities to include on the Phase 1 Report
  3. Focuses on CWS that are deemed “low susceptibility” (those with nitrate levels less than 5 mg/L, nitrates not trending upward and a confining layer exists)
  4. Can assist the low risk CWS to review their Phase 1 report and if requested, proceed independently with help from the:
Additional Resources