The Iowa Department of Natural Resources (DNR) is the state agency responsible for water quality management in the state. Through mandates of the Clean Water Act (CWA) and through regulations of the U.S. Environmental Protection Agency (EPA), the Iowa DNR conducts the following water quality management activities: (1) water quality standards program, (2) point source control program, and (3) nonpoint source control program. The Iowa DNR manages water quality through implementation of water quality standards which are designed to protect and enhance the quality of all waters of the state through prevention and abatement of all point source and nonpoint source pollution to all waters to the fullest extent possible consistent with statutory and technological limitations. The Iowa DNR is the agency responsible for preparation of the Iowa water quality inventory and status report as required by Section 305(b) of the federal Clean Water Act.

The goal of the Federal Water Pollution Control Act Amendments of 1972 (commonly called the Clean Water Act) is "to restore and maintain the chemical, physical, and biological integrity of the Nation's waters" (Section 101(a)). Thus, water quality is made up of three components. The first component is the chemical quality of the water, which is whether the water has sufficient levels of dissolved oxygen, clarity, and lack of toxic substances to allow aquatic life to grow and reproduce, and whether the water can be used for swimming or as a source of drinking water for a public water supply. The second component is the physical quality of the aquatic habitat, including pools, riffles, woody debris piles, deep water, etc. needed by aquatic life to grow and reproduce so that the water can support viable and harvestable populations of fish for recreational and commercial uses. The third component is biological quality that includes the expected kinds and numbers of fish, aquatic insects, and algae that should inhabit the waterbody in the absence of chemical or physical damage.

Section 305(b) of the Federal Water Pollution Control Act Amendments of 1972 (commonly known as the Clean Water Act) require each state to report every two years on the overall status of its water quality and on the degree to which its waters support their designated beneficial uses. Since Section 305(b) reporting began in 1975, 11 of these water quality reports have been prepared for the state of Iowa. State 305(b) reports are summarized by the U.S. EPA into a National Water Quality Inventory that is transmitted biennially to the U.S. Congress. Section 305(b) reporting is the principal means by which the EPA, the U.S. Congress, and the public evaluate current water quality, progress made in improving water quality, and the extent of remaining problems. Summaries of state Section 305(b) reports and other water quality information can be found at EPA's office of water page for Iowa at http://www.epa.gov/ow/states/IA/.

A limited number of Section 305(b) reports have been printed for free distribution while available. If you would like a copy of the most recent Section 305(b) water quality report for Iowa, please contact John Olson of the Iowa DNR Water Resources Section at 515/281-8905 (Email: john.olson@dnr.state.ia.us). Or, you may view the Section 305 (b) Report at the following link: 2000 Water Quality In Iowa.

Please refer to the Water Resources Roster.

Iowa surface waters are designated for one or a combination of the following beneficial uses in the Iowa Water Quality Standards: recreational users (Class "A"), aquatic life (Class "B"), and sources of potable water for public water supplies (Class "C"). Each of these uses is protected by water quality criteria, both numeric and narrative, that are described in the Iowa Water Quality Standards. Not all of Iowa's surface waters are designated for beneficial uses. Approximately 12,000 miles of the 27,000 miles of perennial streams and rivers in the state are designated for beneficial uses. Approximately half of the 93,000 acres of lakes and ponds are designated for beneficial uses. For a further discussion of beneficial uses, please refer to Summary of Protected Uses for Surface Waters.

In Iowa, water quality data from monitoring networks and special studies conducted by a variety of state and federal agencies are used to assess the degree to which the state's surface waters support their designated uses. Based on a comparison of water quality data to water quality standards, or based on the professional judgment of DNR staff, the assessed waterbodies are placed into categories that indicate the level of water quality.

Do you wonder what the current level of water quality in Iowa's surface waters is like? The current Section 305 (b) Report contains the most recent assessment data for Iowa's waterbodies. Please refer to it at 2000 Water Quality In Iowa.

The failure of Iowa's assessed waterbodies of all types to fully support their designated uses has been attributed primarily to nonpoint sources of pollution. These nonpoint source impacts include modification of stream habitat or hydrology and delivery of sediment and plant nutrients from agricultural sources to waterbodies. There are also natural causes, such as natural shallowness in lakes, which are responsible for some waterbodies not meeting designated uses. Point sources have been identified as contributing to water quality impacts on a relatively small number of the waterbodies in Iowa. This small number reflects the success of Clean Water Act programs to control municipal and industrial point sources. The majority of impacts to water quality of wetland and flood control reservoir acres has been attributed to nonpoint sources. For more information about nonpoint sources, please refer to Nonpoint Source Information.

Groundwater is an extremely valuable natural resource in Iowa. Most public and private water supplies in the state utilize groundwater. Good quality groundwater is available in sufficient quantity to meet most water supply needs throughout much of the state. For a further discussion of groundwater, please refer to More Information About Surface Waters and Groundwater.

At the request of the Environmental Protection Agency (EPA), the DNR conducts a thorough review of the Water Quality Standards every three years. This is known as the Triennial Review. Currently, the DNR is proceeding with the 2000 Triennial Review.

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