Effective July 1, 2025, Equivalent Residential Unit (ERU) calculations will be validated using updated mapping of each property’s impervious surface area. This initiative ensures that storm water utility charges accurately reflect the number of ERUs, based on the current standard of one ERU per 3,000 square feet of impervious surface.
As a result of this validation:
Residential properties generally experienced minimal changes in their ERU assessments—except where driveways, accessory buildings, or similar features have been added within the past 15 years. Most residential parcels remain classified within the range of 1 to 2 ERUs.
Commercial properties may see more substantial adjustments due to factors such as parking lot expansions, new construction, redevelopment, or updated measurements to comply with the City’s current ordinance.
This process aligns ERU assessments with up-to-date surface data, promoting fairness and consistency in stormwater billing.
Questions about this validation process can be made to City Administration at 515-645-6808.
Storm Water Fee
In Windsor Heights 3,000 sq. ft. of impervious surface equates to 1 ERU (equivalent residential unit), which is the multiplier for the storm water fee.
The fee enables the City to:
Enhance Infrastructure: Upgrade and maintain storm water drainage systems to better handle heavy rainfall and reduce the risk of flooding.
Environmental Protection: Implement measures to mitigate pollution and protect water quality in our streams, rivers, and lakes.
Compliance and Regulations: Ensure compliance with local, state, and federal regulations regarding storm water management.
The storm water fee structure is as follows:
Effective July 1, 2024: $9.00 per ERU
Effective July 1, 2026: $9.50 per ERU
Effective July 1, 2028: $10.00 per ERU
Effective July 1, 2030: $10.50 per ERU
Storm Water Analysis & Future Projects
A Storm Water Management Plan of its existing storm sewer infrastructure was completed in 2018. The plan included an investigation of the existing storm sewer infrastructure, storm water conveyance alternatives and preliminary layout for improvements to the storm sewer system within the corporate limits of the City of Windsor Heights. The recommended solutions included more than $15.5 million in storm water improvements are intended to improve the City’s drainage characteristics as part of continued street improvement projects.
The improvements that were investigated in this study include new storm sewer lines, manholes, and intakes. The existing storm sewer system within the study area consists of areas with undersized storm sewer mains and inadequate intake spacing. The combination of undersized storm sewer mains and minimal intakes causes a significant amount of localized flooding throughout the study area.