This map shows the reach of the Scott-Highbridge Legal Drain near Interstate 65 in Greenwood. A 1,300-foot segment of the ditch is planned to be reconstructed later this year.
SUBMITTED MAP
Increased development near Interstate 65 in Greenwood has left a portion of a drainage ditch in need of nearly $350,000 of work.
The Scott-Highbridge legal drain on Greenwood’s east side runs from south of Commerce Parkway West Drive to Grassy Creek. The drain, which connects to Sugar Creek via Grassy Creek and Youngs Creek, is part of a watershed that covers nearly 450 acres, county documents say.
The section of the drain to be repaired is a 1,300 feet segment that runs from south of Commerce Parkway West Drive to under I-65. The drain is undersized in relation to the amount of runoff it carries from nearby developments.
The issue stems from an increase in development in the areas surrounding the drain, said Greg Cantwell, Johnson County surveyor. The drain was constructed to handle water from a farm field, not from an industrial park.
“(The need to reconstruct) is a direct result of the development in the area,” he said.
A report commissioned by the Johnson County Drainage Board found there was evidence of erosion around two culverts, including one that is submerged and/or collapsed. Both culverts are in poor condition and are causing water flow issues. Because of this, culverts need to be repaired, along with additional improvements, the report says.
The report concluded the open ditch should be converted to a two-stage ditch system, to accommodate larger flows by giving excess water a large area to rest in. By doing so the ditch will be able to handle stormwater more effectively, the report says.
The repairs are expected to cost nearly $349,758 over five years, including a 20% contingency in case of cost overruns. The section in need of repairs is located near land zoned as industrial by the city of Greenwood, Cantwell said.
Drainage board attorney Roger Young questioned the decision to not include all of the contributing developments in the plans for assessment and reconstruction as they are all part of the reason for the reconstruction. Cantwell told the drainage board about 90% of the area is being proposed to be reassessed, he said.
The city of Greenwood is willing to work with the county to help reduce the costs of the reconstruction and reduce the overall cost to applicable property owners on the drain.
“We’d like to continue to work with the surveyor to find some cost savings in the reconstruction of this section,” said Chris Jones, a representative of the city’s stormwater department.
The reassessment is the first to be initiated following growth in the past few decades. The last time the maps were updated was in the 1980s, Cantwell said.
The surveyor’s office is planning to look at all 49 watersheds in the county as part of a project to update watershed maps. The project will determine what properties are part of each watershed and reassess drainage rates that are paid by property owners, Cantwell said.
The update will also look at the need to repair drains, and prepare for future land use and maintenance, according to county documents.
“Overall, the county is experiencing a lot of unprecedented growth everywhere, and all of the drains throughout the county are going to be looked at,” said Kevin Walls, county commissioner and drainage board member.
