Board approves change to stormwater ERU, shifting modest costs to commercial properties

The Board of Public Works voted June 8 to amend municipal code section 27-5 to adopt an equivalent runoff unit (ERU) of 3,767 square feet for the city's stormwater utility, a change staff said will shift a greater share of stormwater costs to commercial and industrial parcels while leaving single-family residential bills unchanged.

Scott, a city staff member leading the proposal, told the board that advances in GIS mapping make the updated ERU calculation more accurate than the method used when the utility was established in 2005. "What this means for the typical residential family who pays the stormwater utility? Nothing," Scott said, adding that the change primarily affects commercial and industrial lots.

Scott gave a staff example showing a very large commercial parcel would see its stormwater charge move from roughly $40,004.70 under the current calculation to about $41,004.64 under the proposed ERU, an increase of roughly $1,000. He said the updated ERU standard (3,767 square feet) reflects modern parcel measurement and is intended to better apportion costs to impervious area on nonresidential properties.

The chair asked whether the change would reduce revenue for the utility; Scott replied it would not reduce current residential bills and that any future citywide rate increases would affect all property classes equally. After brief questions seeking clarity on the effect for single-family homes, the board approved the ordinance amendment by voice vote.

The board's approval sends the amended ordinance forward for the next procedural steps required under city code. The board did not specify an immediate effective date during the meeting; staff said billing impacts are tied to the adopted ERU and future rate-setting decisions.