Protecting Aquatic Life in Iowa Rivers and Streams

Iowa is fortunate to have two excellent aquatic life monitoring programs. These include the professional Ambient Water Monitoring Program (wqm.igsb.uiowa.edu/) and the IOWATER program (www.iowater.net/) - the volunteer water quality monitoring program administered by DNR. Many Iowans are participants. They know about the importance of benthic macroinvertebrates in the stream, not only to the health of the aquatic ecosystem, but also as qualitative and quantitative measures of the stream's water quality. Mayflies, caddis flies, riffle beetles, damsel flies, scuds.... all of these little critters spend the majority of their life cycle attached to, or floating near, the bottom of the stream.

When a pollution event occurs most of them cannot just swim away. They bear it all. As such, they integrate all of the acute and chronic pollution events occurring throughout their life (or death) cycle. The diversity and abundance of benthic macroinvertebrates correlates directly to the health of a stream. Although the metrics used may vary from eco-region to eco-region, the Index of Biotic Integrity (IBI) calculated from identifying and counting these critters is a powerful measure of water quality.

The Clean Water Act considers the presence of aquatic life an "existing use" and has this to say about it:

"Non-aberrational resident species must be protected, even if not prevalent in number or importance. Water quality should be such that it results in no mortality [acute toxicity] and no significant growth or reproductive impairment [chronic toxicity] of resident species. Any lowering of water quality below this full level of protection is not allowed."   -EPA Water Quality Standards Handbook - Second Edition, 1994

Then why is it that Iowa's Water Quality Standards (WQS) do not protect aquatic life from chronic pollution effects in 83% of all Iowa river and stream miles? In fact, most IOWATER monitoring sites - perhaps YOURS - are located on "general use" streams not protected for aquatic life! To learn more... (PDF 127 Kb)

Historically, the scope of the Clean Water Act has been interpreted in the broadest possible sense to encompass as many of the nations' waters as possible, and for good reason. All surface waters (and most ground waters) are inextricably interconnected. Small streams lead to bigger streams, rivers lose water to the aquifer in one location only to be replenished as water from that same aquifer emerges as springs and seeps.

The current attempt of the Bush administration to severely limit the scope of the CWA by removing protection from many wetlands, intermittent and perennial headwater streams resulted in a groundswell of opposition from environmentalists, conservationists, sportsmen and scientists. One result has been an increased awareness regarding the vital role that wetlands, bogs, and headwater streams play in improving water quality and supporting abundant and diverse aquatic life. To learn more, read the definitive document "Where Rivers Are Born" (PDF 1.1 Mb) or "Where Rivers Are Born" (text version 33 Kb).

Although the Bush administrations' proposed rule has been taken back, the administrative order restricting enforcement of pollution violations has NOT been rescinded. With little more than a wink and a nod, the pollution is allowed to continue.