Cobb County water system proposes stormwater utility with $4.75 residential fee, impervious-area commercial charges

Cobb County Water Systems presented a comprehensive proposal Oct. 28 to establish a stormwater utility and adopt multiple code changes in Chapters 50, 83, 110 and 122. Judy Jones, presenting the package, said the county currently funds stormwater through water and sewer rates and a transfer to the general fund, which makes it difficult to track revenue dedicated to stormwater. Jones said the county estimates it currently receives roughly $7.5 million in stormwater-related revenue but has a budgeted stormwater program need closer to $9.2 million; the proposal would expand the program and fund a larger, multi-year capital plan.

Key elements of the proposal:

- Create a stormwater utility for unincorporated Cobb County (and for municipalities by IGA) and establish a dedicated fee mechanism. The water system would administer the program. - Residential fee: a flat monthly charge of $4.75 per equivalent residential unit (ERU). Jones said the ERU is defined as a median residential impervious area of 3,700 square feet; residential customers would be charged the flat fee regardless of water use. - Nonresidential (commercial) charges: calculated by dividing a parcel's measured impervious area by 3,700 sq. ft. and multiplying by the ERU fee. - Credits and exemptions: a credit manual would be adopted by the Board to allow reductions (typical maximum 40% credit for mitigation measures; up to 50% for full on-site infiltration or exceptional measures). Exemptions would include undeveloped land, railroads, airport runways, certain DoD-permitted areas (Dobbins), and parcels that infiltrate 100% of runoff up to and including the 100-year, 24-hour storm event. - Billing, appeals and administration: monthly stormwater fees would appear on water bills for customers served by the water system; properties not served by the water system would receive a separate stormwater bill. An administrative appeals process would route disputes from the water system director to the Board and then to superior court. - Implementation and services: the proposal would discontinue county acceptance of new residential detention ponds and would require private stormwater facilities serving multiple properties to be governed by property-owner associations. Jones proposed additional maintenance crews, funding for backlog pipe repairs, limited riprap for severely eroded residential channels, higher payments for purchased lake-storage volume, and $1.5 million per year to help DOT address county-right-of-way drainage repairs.

Jones acknowledged significant public interest and said public hearings would be held Nov. 12 and Nov. 20; the Board will separately consider a resolution to set the fee. Staff said they plan a phased implementation targeted for June 1, 2026 if the Board approves code and fee actions. Commissioners asked detailed questions about the relationship between a separate stormwater fee and existing water/sewer transfers to the general fund, the scope of credits, impacts on commercial accounts and how exemptions would be verified.