Value of tougher subdivision regulations proven with submittal

Less than six months after adoption, Kenton County’s brand new subdivision regulations are accomplishing one of their primary goals. Streets in Crestview Hills’ newest subdivision will be built on newly-placed subsoils that will provide necessary support for the long term. The city’s taxpayers are the true beneficiaries of the changes.

“One of staff’s original objectives (in working toward new construction standards) was to extend street life and preclude the taxpayers from having to pay for premature failures,” said Scott Hiles, CPC, Director of Infrastructure Engineering. “The new regulations require an evaluation of the subgrade soils’ suitability to determine whether they can provide the strength necessary to support the pavement.”

The types of soils that are problematic and contribute to street failure are common throughout Northern Kentucky.

The first development to be submitted after the new regulations took effort was a 42-lot development on 22 acres in Crestview Hills to be named Crown Point. It includes a single new street of slightly more than 2,300 feet. Not surprisingly, when the required soil evaluation was performed, its findings identified problematic subgrade soils that would not provide the required strengths to support the pavement.

“Staff was surprised that the very first development submitted under the new regulations was located on a site with the problem soils we wanted to keep an eye-out for,” said Hiles. “But, it allowed us to quickly recognize that the process we put in place worked. Had these new regulations not been in place, we wouldn’t have known about the soils until after the streets began to fail prematurely.”

“We were quite pleased that this first subdivision proved that the new regulations brought value to the community right out of the gate.”

Hiles said the developer plans to remove the problem subgrade soils from the site and replace them with soils that will provide the support necessary for the street. The developer plans to finish the earthwork and construct the street yet this year which should result in the availability of new building lots late in 2015 or early 2016.

Adoption of the new subdivision regulations completed a multi-year effort by the Kenton County Planning Commission and PDS staff. It was kicked off in 2011 with several identified goals, the most important being to create a set of regulations that provided enhanced material specifications and design controls to ensure that new streets would last a minimum of 20 years as designed. Extending the lives of these streets would reduce the cost borne by taxpayers to repair premature and costly failures.

Working with a committee of planning commission members, engineers, local mayors, and homebuilders, staff was successful in seeing that the requirement to evaluate the strength of a development’s subgrade soils was included in the adopted regulations.

“Based on the individual circumstances and test results, when poor subgrade soils are identified by the required evaluation, the regulations establish procedures to either increase subgrade soil strengths or the design of the pavement itself,” Hiles concluded.

Kenton County’s new Subdivision Regulations can be found online.