Delaware Stormwater Fee-in-Lieu Amount Updated to $27/CF

DNREC Sediment & Stormwater Listserve Update: January 2026

This month's topics:

1. Fee-in-Lieu Amount Updated
2. Regulatory Guidance Memoranda Effective January 1, 2026
3. DURMMv2.6 Status

4. Post-Construction Stormwater BMP Standards and Specifications Update Public Notice

5. Fee-in-Lieu Amount Updated
   The Delaware Sediment and Stormwater Regulations (7 DE Admin. Code 1501, subsection 13.2) allows for an annual adjustment of the Stormwater Management Fee-in-lieu. Using the Engineering News Record's building and construction cost indices for Philadelphia, the fee-in-lieu offset for full or partial compliance has been adjusted to $27 per cubic foot of runoff volume. The $27/CF amount applies to fees-in-lieu paid beginning January 1, 2026.

6. Regulatory Guidance Effective January 1, 2026
   The following Regulatory Guidance Memoranda (RGM) were published November 1, 2025 and have effective dates of January 1, 2026:

• RGM-1v.2 requires NOAA rainfall distribution curves to be used in stormwater
  computations.

• RGM-4 provides procedures for notification of stormwater discharges to DelDOT.

• RGM-5 provides a computational tool to assist applicants in confirming that Standard Plan
  Criteria are met. Revisions to the Delaware Erosion and Sediment Control Handbook Section 3.6.1 were published December 1, 2025, and the revised Handbook has a new effective date of January 2026. All standard details included on plans to be approved on or after January 1, 2026, should include the latest Handbook details containing the "Effective January 2026" stamp.

1. DURMMv2.6 Status
   An update to the Delaware Urban Runoff Management Model (DURMM) was published on November 1, 2025. Based on feedback received, DURMMv2.6 will be further refined and published at a later date along with additional regulatory guidance to accompany this version. Until that time, DURMMv2.51.220414 currently available on the Sediment and Stormwater Program website should continue to be used.

2. Post-Construction Stormwater BMP Standards and Specifications Update Public Notice
   The safety features portions of Sections 10.0 Detention Practices, 12.0 Constructed Wetlands, and 13.0 Wet Ponds of the Post-Construction Stormwater BMP Standards and Specifications have been revised to state, in non-bold language, that stormwater management systems with a permanent pool, and that are reasonably accessible to the public, should include barriers to restrict public

access while not impeding the facility's function or restrict necessary maintenance access. This is noticed in the January 2026 Register of Regulations and available for public review at https://dnrec.delaware.gov/watershed-stewardship/sediment-stormwater/