The D.C. Department of Energy and Environment (DOEE) issued a second proposed rulemaking (Proposed Rule) on May 30, 2025, to amend the District's Stormwater Management and Soil Erosion and Sediment Rules (Stormwater Rules) contained in Chapter 5 of Title 21 of the District of Columbia Municipal Regulations (DCMR).
The Proposed Rule incorporates and slightly revises a previous proposed rulemaking issued in 2020 but never finalized (2020 Proposed Rule). The 2020 Proposed Rule provided certain clarifications and expansions of the existing Stormwater Rules, which require major regulated projects to install green infrastructure (GI) practices to capture stormwater runoff, and allowed site owners of major projects to use Stormwater Retention Credits (SRCs) in lieu of installing GI practices at their properties. Specifically, the 2020 Proposed Rule created three categories of SRCs based on the level of benefits achieved from the project: High-Impact, Tier I and Tier II.
In response to public comments, this second Proposed Rule makes several revisions to the 2020 Proposed Rule, including:
Categorization of SRCs. The Proposed Rule removes the Tier I and Tier II categories and instead distinguishes between High-Impact SRCs and Low-Impact SRCs. Generally speaking, High-Impact SRCs are those that are considered more environmentally impactful due the location and project size/type, whereas Low-Impact SRCs are considered to have less impact on the environment:
- High-Impact SRCs – SRCs that have the following characteristics: 1) installation after July 1, 2013, 2) capture stormwater that would otherwise drain to the municipal separate storm sewer (MS4) area and not be captured because there is no project that would trigger stormwater management regulations and 3) the size of the project is such that its capacity "fills up" with each storm
- Low-Impact SRCs – SRCs that have the following characteristics: 1) installation can be before July 1, 2013, 2) capture stormwater that would otherwise drain to the Combined Sewer System (CSS) or to the site of a project that is already subject to stormwater management requirements and 3) the size of the project is such that its capacity "fills up" only occasionally
Prioritizing High-Impact SRCs. The Proposed Rule prioritizes High-Impact SRCs to accelerate the construction of voluntary GI in the MS4 area. The purpose of this prioritization is to preserve flexibility and increase water quality benefits by requiring site owners who have an Off-Site Retention Volume (Offv) to purchase available and affordable High-Impact SRCs before allowing them to purchase Low-Impact SRCs. This proposed prioritization concept involves three aspects: 1) requiring SRC buyers to use High-Impact SRCs if they are available, 2) allowing site owners to use High-Impact SRCs when self-generating SRCs to comply with an Offv and 3) giving all site owners the option to pay the in-lieu fee instead of using SRCs.
Two-Year Storm Detention Exemption. The Proposed Rule waives two-year storm detention requirements for projects that meet the following criteria: 1) located in the Gray CSS (i.e., area where most of the stormwater is already captured by large tunnels that flow to the DC Water treatment plant), 2) comply with at least 50 percent of their Stormwater Retention Volume (SWRv) requirement off-site and 3) the owner uses High-Impact SRCs to comply with the Offv requirement.
Permanently Satisfying an Offv Requirement in the Gray CSS Area. The Proposed Rule will allow site owners to permanently satisfy an Offv requirement in the Gray CSS area if the following conditions are met: 1) the project must be located in the Gray CSS, 2) the owner must submit the initial application to the DOEE within three years of the effective date of this rulemaking or substantial completion of the project, and 3) the owner must use only High-Impact SRCs for 30 consecutive years.
SRC Eligibility Deadline. The current Stormwater Rules require SRC generators to submit their first application to certify SRCs within three years after installing a qualifying GI practice. The DOEE certifies SRCs for up to three years at a time, and the SRC generator has up to six months after an SRC certification period ends to submit its next application. The Proposed Rule seeks to extend the six-month deadline to allow an SRC generator to submit the next application within three years after the end of the prior certification period.
Additional Revisions
The Proposed Rule also includes several other revisions, including:
- clarification of the requirement that a user cannot share login credentials or account information for DOEE's submission database
- allowing applicants to exclude the cost of solar energy generation when calculating the cost of a major substantial improvement activity, subject to DOEE approval
- permitting licensed landscape architects and licensed contractors, in addition to engineers, architects and land surveyors, to design a soil erosion and sediment control (ESC) plan
- allowing any SRC to be replaced by a retired High-Impact SRC and allowing retiring a Low-Impact SRC only when it replaces another Low-Impact SRC
Final Flood Hazard Rules
The DOEE adopted a final rulemaking (Final Rule) on June 10, 2025, amending the District's Flood Hazard Rules contained in Chapter 31, Title 20 of the District of Columbia Municipal Regulations (DCMR), which governs development projects located in a Federal Emergency Management Agency (FEMA)-designated floodplain. The Final Rule was designed to develop safer building practices in the District to reduce public and private losses caused by flooding events and prepare the District, its residents and structures for the anticipated impacts of climate change and sea level rise.
The highly anticipated Final Rule comes after several years of stakeholder engagement by the DOEE – including solicitation of public comments and several technical workshops – that began in 2020 when the DOEE previewed its updates to the Flood Hazard Rules to address the increased risk of flooding posed by climate change and sea level rise. (See Holland & Knight's previous alert, "D.C.'s Department of Energy & Environment Proposes Major Changes to Flood Hazard Regulations," April 7, 2020.)
Most recently, the DOEE published a proposed rulemaking (Proposed Rule) in July 2024 that made several substantial modifications to the Flood Hazard Rules in response to stakeholder input. The DOEE accepted public comments on the Proposed Rule until Sept. 2, 2024. (See Holland & Knight's previous alert, "D.C.'s DOEE Publishes Long-Awaited Proposed Revisions to District Flood Hazard Rules," July 30, 2024.) Notably, in the Final Rule, the DOEE announced that it was adopting the Proposed Rule as the final rule without any further changes. However, the DOEE did clarify some aspects of the Final Rule based on comments submitted by stakeholders.
The Final Rule became effective upon publication in the DC Register on June 20, 2025. As a result, all new construction and substantial improvement projects in the District that are located within FEMA's 100- or 500-year floodplain will be required to comply with the Final Rule, unless otherwise exempted.
A summary of the key components of the Final Rule is below. Further details can be found in the aforementioned July 30, 2024, Holland & Knight alert summarizing the Proposed Rule.
- Flood Hazard Area. The Flood Hazard Rules previously governed activities within FEMA's 100-year floodplain. The Final Rule expands the regulated "flood hazard area" to include lands within the FEMA 500-year floodplain, including any area that has been removed from a flood hazard area due to a Letter of Map Revision Based on Fill (LOMR-F) and areas on Rhode Island Avenue NE that are susceptible to interior flooding. In response to one commenter, the DOEE also clarified that existing structures within the Flood Hazard Area will not be considered out of compliance as a result of the Final Rule. Rather, the Final Rule will apply only to new construction or substantial improvements (see below) in those areas.
- Substantial Improvement. The Final Rule modifies the definition of "substantial improvement" to generally include "any combination of repairs, reconstruction, rehabilitation, additions, modifications, or improvements of a building or structure made during the 5-year period immediately preceding a permit application." Some exemptions exist for certain projects in the 500-year floodplain.
- Design Flood Elevation. The Final Rule changes the design flood elevation (DFE) to either the 100-year flood elevation plus two feet of freeboard or the 500-year flood elevation, whichever is higher.
- Covenants and Agreements. The Final Rule requires applicants to file a covenant regarding the operation and maintenance obligations for dry floodproofing systems, and to file a non-conversion agreement in the land records so that an approved nonresidential use is not later converted to a residential use.
- No Adverse Impact. The Final Rule requires applicants to demonstrate that their proposed development in a flood hazard area will cause no adverse impact to other properties via a No Rise Certification.
- Hazardous Materials. The Final Rule requires property owners/developers to report the storage of more than 550 gallons of an expansive list of hazardous materials, prepare a flood emergency action plan and comply with the requirements for "critical facilities."
- Critical Facilities. The Final Rule prohibits new or substantially improved critical facilities (including hospitals, shelters, schools, power stations and others) located in flood hazard areas without an alternatives analysis and stringent protective measures.
- Underground Parking Garages. The Final Rule maintains the existing prohibition on underground parking garages below residential-only multifamily structures in the 100-year floodplain. Mixed-use projects may have underground parking garages "by right" without the need to obtain a variance or code modification, although they will need to meet certain design criteria specified in Section 3108.8.
- Historic Structures. The Final Rule requires coordinated review with the State Historic Preservation Office (SHPO) to ensure that required floodproofing is achieved to the maximum extent practicable while still maintaining the structure's historic designation.
- Tidal Shoreline Buffer. The Final Rule creates a Tidal Shoreline Buffer that would include areas that are expected to be inundated by sea level rise by the year 2080 (approximately 1 percent of private land). Construction within the Tidal Shoreline Buffer requires submission of an evaluation plan, a comprehensive resilient systems plan and an alternatives analysis.
- Mixed-Use Projects. The Final Rule requires the lowest floor of any mixed-use building to be at or above the DFE or designed and constructed to be dry-floodproofed during any flood up to the DFE. The lowest floor of the residential portion of any mixed-use building would be required to be at or above the DFE. In response to one commenter, the DOEE clarified that "minor retail elements" will not be sufficient to classify a residential building as mixed-use and that applicants should refer to the District's Construction Code for details on mixed-use building requirements.
- Fees. Under the Final Rule, fees to administer the program will range from approximately $800 for one- to two-unit dwellings to up to $10,000 for major developments involving four or more floors or six or more residential units. Fees will also be imposed for other activities such as predevelopment meetings and resubmission fees.
