Michigan's Water Withdrawal Assessment Process and Internet Screening Tool

摘要

Michigan's Water Withdrawal Assessment Process is used to regulate new or increased large quantity withdrawals (more than 100,000 gallons of water per day) from any source. The purpose of the regulation is to prevent Adverse Resource Impacts on streams. The Water Withdrawal Assessment Process is ecologically based, built around a stream classification system and expected fish communities for those classifications. Every stream in the state is classified as one of eleven habitat types. Fish community responses were modeled as an outcome of changes in streamflow for each stream type. Through a legislative process, the resulting fish response models were used to determine and define in statute the maximum withdrawals allowed for each stream type as a percentage of an Index Flow. To facilitate decision making, an Internet-based Screening Tool was developed to estimate the impact of withdrawing water on the nearby stream ecosystems. The Screening Tool processes data about factors such as stream flows, pumping frequency, well depth, watershed areas, soil types, and the flow needs of the characteristic fish community.