D.C. Mun. Regs. tit. 21, § 2607
2607.1 The objective of mitigation is to offset functional, temporal, and permanent environmental losses resulting from unavoidable impacts to wetlands and streams authorized by wetland and stream permits and water quality certifications.
2607.2 An applicant must propose and provide justification for an appropriate mitigation project to offset unavoidable impacts to wetlands or streams and obtain the Department's approval of a mitigation plan in accordance with § 2608.
2607.3 Mitigation for wetland and stream impacts is not required for the following regulated activities:
(a) Activities exempted in § 2601; and
(b) Activities which result in temporary impacts to wetlands or streams.
2607.4 A mitigation project:
(a) Shall comply with the District's surface water quality standards;
(b) As a source of its hydrology, may only receive stormwater runoff from stormwater management practices required pursuant to chapter 5 of this title or by a permit issued pursuant to CWA § 402 (33 U.S.C. § 1342), provided that the stormwater runoff meets District's surface water quality standards before entering the wetlands or streams; and
(c) Shall not be constructed to serve as a stormwater management best management practice for the purpose of compliance with 21 DCMR Chapter 5.
2607.5 An applicant shall complete mitigation, to the maximum extent practicable, in advance of, or concurrent with, the approved regulated activity.
2607.6 The mitigation mechanism shall be either permittee-responsible mitigation or, if authorized in accordance with § 2607.18, payment into the District of Columbia's Wetland and Stream Mitigation Trust Fund.
2607.7 An applicant may perform permittee-responsible mitigation using creation, restoration, enhancement, or preservation of wetlands or streams, or a combination any of those methods.
2607.8 Mitigation projects may be located on multiple parcels of land.
2607.9 Mitigation projects shall be located:
(a) In the District;
(b) Where they are most likely to successfully replace functions lost as a result of the project, taking into account habitat diversity, habitat connectivity, hydrology, trends in land use, and compatibility with adjacent land uses; and
(c) According to the following geographic location, in order of priority, unless otherwise determined by the Department:
(1) On-site where the wetland or stream impact(s) will occur;
(2) In the drainage basin where the wetland or stream impact(s) will occur;
(3) In the sub-watershed where the wetland or stream impact(s) will occur;
(4) In the watershed where the wetland or stream impact(s) will occur; or
(5) Outside the watershed where the wetland or stream impact(s) will occur.
2607.10 Except as provided in § 2607.18 the permittee shall install and maintain the mitigation project.
2607.11 In selecting sites for mitigation within geographic regions, an applicant shall avoid, whenever possible, the following types of sites:
(a) Forested lands;
(b) Lands known to have soil and groundwater contamination;
(c) Lands that have or will have limited access for wildlife or aquatic life because of traffic or other human activities;
(d) Lands that are existing or potential habitat for any species that are:
(1) Listed as endangered or threatened by the Department or the U.S. Fish and Wildlife Service; or
(2) Considered to be locally unusual, rare, or identified as a species of greatest conservation need in the District Wildlife Action Plan, accessible on the Department's website; and
(e) A site designed or constructed to remove or treat pollutants from stormwater runoff.
2607.12 The applicant shall calculate mitigation requirements as follows:
(a) The minimum mitigation ratio, between the area of wetland or stream mitigation and the area of wetlands or streams impacted, shall be 1:1; and
(b) The mitigation shall:
(1) Where appropriate functional or condition assessment methods or other suitable metrics are available, replace all lost wetland or stream functions; or
(2) Where functional or condition assessment methods are not available or replacement of all lost wetland or stream functions is not possible, mitigate impacts using the mitigation ratios in § 2607.14 and § 2607.15.
2607.13 A mitigation ratio shall be expressed as:
(a) A relationship between the area of wetland mitigation and the area of wetlands impacted; or
(b) A relationship between the area of stream mitigation and the area of streams impacted.
2607.14 The mitigation ratios for impacts to streams, when functional or condition assessment methods or other suitable metrics are not available, shall be as follows :
| Type of Stream | Restoration Ratio | Preservation and Enhancement Ratio | District Wetland and Stream Mitigation Trust Fund Payment |
|---|---|---|---|
| Ephemeral | 1:1 | 1.5:1 | 1.5:1 |
| Intermittent | 2:1 | 3:1 | 3:1 |
| Perennial | 2:1 | 3:1 | 3:1 |
2607.15 The mitigation ratio for impacts to wetland areas, when functional or condition assessment methods or other suitable metrics are not available, shall be as follows :
| Wetland Type | Mitigation Method | ||
|---|---|---|---|
| Creation/Restoration | Enhancement and Preservation | District Wetland and Stream Mitigation Trust Fund Payment | |
| Emergent | 1:1 | 1.5:1 | 1.5:1 |
| Scrub-shrub | 2:1 | 3:1 | 3:1 |
| Forested | 2:1 | 3:1 | 3:1 |
| Emergent Wetland of Special Concern | 2:1 | 3:1 | 3:1 |
| Scrub-shrub Wetland of Special Concern | 3:1 | 4.5:1 | 4.5:1 |
| Forested Wetland of Special Concern | 3:1 | 4.5:1 | 4.5:1 |
2607.16 The Department may accept reduced mitigation requirements if the regulated activity provides a significant environmental benefit as determined by the Department.
2607.17 The Department shall require higher mitigation ratios for activities conducted without or prior to obtaining a permit or certification required by this chapter, as follows:
| Resource Type | Restoration/ Creation Ratio | Preservation and Enhancement Ratio | District Wetland and Stream Mitigation Trust Fund Payment |
|---|---|---|---|
| Stream | 3:1 | 4:1 | 4:1 |
| Wetland | 4:1 | 5:1 | 5:1 |
2607.18 A permittee may fulfill the mitigation requirement for damage to or destruction of habitat from dredge-and-fill or construction activity through payment into the District's Wetland and Stream Mitigation Trust Fund if:
(a) Permittee-responsible mitigation is not practicable based on
the justification and a determination of the considerations provided in accordance with §§ 2607.19 and 2607.20; or
(b) Cumulative impacts for a single project total less than or equal to two thousand five hundred (2,500) square-feet.
2607.19 If an applicant proposes payment into the District’s Wetland and Stream Mitigation Trust Fund, the applicant shall demonstrate to the satisfaction of the Department that all practicable mitigation alternatives have been analyzed and that permittee-responsible mitigation is not practicable.
2607.20 In determining whether payment into the District’s Wetland and Stream Mitigation Trust Fund is justified and permittee-responsible mitigation is not practicable, the Department will consider the following:
SOURCE: Final Rulemaking published at 68 DCR 5254 (May 14, 2021).