Why does IDEM require compensatory mitigation?
IDEM frequently requires an applicant to perform compensatory mitigation (wetland & stream replacement or restoration) when an applicant proposes to fill an existing wetland or impact an existing stream, lake, river, or other Water of the U.S. Indiana’s antidegradation rules require existing uses of all Waters of the U.S. to be maintained and protected; they also prohibit any degradation of water quality that would interfere with or become injurious to existing and potential uses; see 327 IAC 2-1-2 and 327 IAC 2-1.5-4. Filling a wetland eliminates its existing and potential uses. Therefore, IDEM would not be maintaining and protecting the uses of that Water if IDEM did not require replacement of the filled wetland. Additionally, the filled wetland would violate the state’s narrative minimum surface water quality standards (327 IAC 2-1-6 and 327 2-1.5-8) if mitigation were not provided for its impact. In other words, compensatory mitigation provides IDEM with the flexibility to authoriz
