Street standards continue to stymie sub regs committee

The Kenton County Planning Commission’s Subdivision Regulation Committee held a second roundtable forum in May. The agenda included the one subject that is precluding action on Kenton County’s new subdivision regulations: upgraded design standards for new Kenton County streets. Since no consensus was reached, a third roundtable forum is scheduled for 2 PM on July 16th at NKAPC.

Beside committee members, those in attendance represented: the Kenton County Mayors’ Group, the Northern Kentucky Homebuilders Association, the Northern Kentucky Society of Professional Engineers, and Henry Fischer of Fischer Homes.

While consensus was not achieved on the larger issue, it was reached on several components of it: 1) only crushed limestone aggregate will be permitted in concrete to reduce D-cracking and surface deterioration; 2) a higher quality of expansion material will be required at all expansion joints to increase their effectiveness and longevity, and to reduce street creep; 3) joints must be skewed to reduce wheel loads; 4) asphalt testing standards must be increased; and 5) detailed pavement analyses must be performed by a geotechnical engineer for all projects to determine any other pavement and drainage enhancements that should be required.

The Subdivision Regulation Committee directed staff recently to address the issue of subsurface drainage by crafting language requiring edge drains under all street curb where 51 percent of the adjoining lot drains toward the street, and in street sag locations extending 50 feet from either side of the sag. These requirements for edge drains are similar to a design proposal made by the Northern Kentucky Society of Professional Engineers. Not all groups in attendance at the May forum agreed on this point.

The Mayor’s Group for example believes strongly that edge drains should be provided under all portions of new street and that a full drainage blanket should be required under all street pavements.

“Committee members agreed that drainage blankets are needed in certain situations,” said Scott Hiles, CPC, NKAPC’s director of infrastructure engineering, “but they believe that rather than require them everywhere as a minimum standard, they should let the geotechnical engineer decide precisely where they are needed as part of the required pavement analysis.”

In addition to requiring a drainage blanket, the geotechnical engineer could require additional drainage improvements such as more edge drains or longitudinal drains, according to some committee members.

Staff is hopeful that this third roundtable forum will produce the needed consensus so the committee can give staff a final directive on what design proposals are to be included in the draft regulations. If that takes place, the last step in the long process will be to take the final draft to a public hearing before the Kenton County Planning Commission.

It isn’t possible to project when that might occur until consensus is reached among members of the committee.