The City of Dover is requesting proposals for engineering services to evaluate replacement alternatives for the culvert conveying an unnamed brook under County Farm Road. The existing culvert is currently experiencing sinkholes near the southern guardrail due to loss of material through the granite headwall. The City stabilized the headwall in January 2024 with the installation of filter fabric at the bottom of the sinkhole; however, the sinkhole formed again in June 2024. The existing culvert was constructed at an unknown date, but is thought to consist of a 14’ wide by 6’ tall stone box culvert that was modified in 1991 to facilitate the installation of the 6” sewer force main over the culvert. Since the installation of the culvert, a concrete pipe appears to have been installed within the box culvert. A 12” AC watermain is also located over the culvert. The unnamed brook appears to originate from the neighborhood to the north and off of Sixth St, flows towards Erik Drive, and then is conveyed under County Farm Road to the Cochecho River. East of the subject culvert is a twin stone box culvert that conveys Reyners Brook under County Farm Road, and does not appear to transect with the unnamed brook.
