City of Owasso

PROJECT PURPOSE

This proposed project would greatly benefit an area of Owasso by solving a multiyear drainage and flooding issue. During heavy rains, portions of the streets in Country Estates become inundated with stormwater in various locations (see Image). Stormwater reaches beyond the City?s right-of-way and approaches the front porches and garage approaches of houses. The HOA in the neighborhood dissolved years ago, and the detention pond didn?t receive regular maintenance. Because of this, problems with shallow water in the detention pond and silt deposits have been ongoing. Backwater from the pond in the storm system has caused additional problems with maintenance, while affecting capacity to an extent. In October 2020, Council approved an engineering agreement with Freese and Nichols to perform a study and H/H analysis. In July 2021, Freese and Nichols completed the study. Staff reviewed and chose alternate #3 ? 100-Year Closed Storm Sewer System with free outfall. The project would include properly sizing all closed storm sewer segments along Lines A, B and C to convey the 100-year peak discharges (see Attachment). This alternative assumes no downstream tailwater and the closed stormwater systems behave in a free outfall condition. The estimated project cost is $3,000,000.00, including engineering and construction.

EVIDENCE

None

POPULATION DESCRIPTION

This stormwater project will help the community by addressing property and street flooding issues. The residents in this area of Owasso have been impacted by the pandemic over the last two years. An improvement in this area will benefit them financially by reducing the number of repairs needed after flooding.

PERFORMANCE MEASURING

The measure of project performance for the County Estates Stormwater improvements will be a reduction in flooding in the neighborhood. A reduction in the number of water rescues performed by the Owasso Fire Department is expected.

ONGOING INVESTMENT AMOUNT

$

ONGOING INVESTMENT DESCRIPTION

None

ONGOING INVESTMENT REQUIRED

Able to continue operation without additional funding from the State of Oklahoma