Thornton Street Improvements

The City of Leavenworth, Kansas regularly conducts a city-wide pavement analysis to rate each street and identify which improvements are most pressing. Thornton Street had been on the city’s radar for years. An east/west collector, the existing two-lane asphalt roadway, curb, and sidewalk were in poor condition. The repairs needed went beyond simple maintenance.

The city retained Affinis to perform a concept study to determine the roadway typical section, roadway geometrics, and project costs. The study recommended reconstructing Thornton to a two to three-lane asphalt pavement section with concrete curb and gutter and a 5-foot sidewalk constructed on both sides of the street, as the most cost-effective solution to meet the city’s design criteria. They selected Affinis to perform the design two years later.

We worked with the city to take a comprehensive approach to make other needed improvements to extend the infrastructure’s life. Together, we determined the large reinforced concrete box (RCB) structures crossing Thornton were in poor condition and should be replaced. This also provided the perfect opportunity to armor downstream erosion and add inlet structures to capture overland flow upstream.

To meet the current and future needs, Thornton Street, from 10th Street to 5th Avenue, was designed to include a two to three-lane section with concrete curb and gutter and a 5-foot sidewalk constructed on both sides of the street. The plans also incorporated storm sewer system replacement and expansion to provide adequate hydraulic capacity. The existing traffic signal at 2nd Avenue was replaced and included ADA compliant features as well.

To meet the city’s best management practices (BMPs), a bioswale was designed for the area within the right-of-way between 7th Street and 5th Avenue. Hydrodynamic separators were also used in areas where right-of-way was limited. The separators are part of the enclosed storm sewer system and capture any trash, silt, and debris before it leaves the system.

The completed project meets each of the city’s goals. They wanted to make all the necessary changes at once, so they would not have to repair it again for many years. As a result, these improvements, increased water quality, safety, and traffic flow, helping to move the City of Leavenworth forward.