The Water Withdrawal Assessment Tool (WWAT) is part of Michigan’s fulfillment of the Great Lakes Compact obligations to conserve and manage our water resources.
- Michigan law prohibits water withdrawals from causing excessive depletion of stream and river flows, called an Adverse Resource Impact (ARI).
- The Water Withdrawal Assessment Tool estimates the potential impact a water withdrawal may have on nearby streams and rivers relative to the ARI limit.
- Landowners planning a new or increased withdrawal using one or more pumps capable of at least 70 gallons per minute must obtain approval from EGLE prior to operation.
- Use of the Water Withdrawal Assessment Tool is required for approval of wells or intakes directly from a stream, river, or pond less than 5 acres.
- Withdrawal approval is attained by a determination of no ARI.
- Approved withdrawals receive an EGLE Water Withdrawal Registration.
- Withdrawals must be operational within 18 months after approval or the Registration becomes void.
The WWAT is the central component of the Water Withdrawal Assessment Process -- the means by which Michigan regulates large quantity withdrawals in the management of our water resources.