Jefferson County Route 155 Culvert Drainage Evaluation
Location: Jefferson County, NY | Completion Date: 2013 | Services Provided: Civil Engineering
Aubertine and Currier was contracted by Jefferson County to complete a drainage evaluation of a 900’ long section of County Route 155 and associated highway culverts. The roadway and culverts had been reconstructed 5 years prior. The County Highway Department had completed modifications to roadside drainage ditches at the site in response to adjacent landowner complaints of flooding of their property since the reconstruction.
An evaluation of the highway reconstruction plans and available mapping was completed. The 31.5 acre drainage area was determined based upon available plans, mapping, USGS maps, and aerial imagery. The drainage areas to the two culverts were defined and modeled utilizing Soil Conservation Service (SCS) methodology. TR55 and TR20 modeling was completed utilizing HydroCAD software to determine the 25 and 100 year runoff to each of the roadway culverts.
Each of the 18” roadway culverts were determine to have adequate capacity to pass the 25 and 100 year storm events without over topping of the roadway, and maintained flows within the drainage channels. The roadside ditch and culverts were constructed with adequate size, elevation and slope.
The determination was made that although the Co Rt 155 roadway and drainage system was revised as part of the 2006/2007 road reconstruction, the current roadway drainage system was not the cause of the recent home basement and lawn flooding. The Co Rt 155 culverts at station 141+50 and 149+40, and the associated upstream culverts within the roadside ditch were sized adequately. Regular maintenance cleaning of the ditches and culvert piping must be performed for optimum capacity of the ditches and culverts.
The adjacent home’s basement flooding was determined to mostly likely be a result of degradation of the foundation drain piping since its original construction in 1987. Likely causes of the foundation drain capacity reduction and resulting basement flooding includes siltation, settlement and root vegetation impacts to the foundation drain piping and surrounding drainage stone bedding.