Stormwater Master Plan

Stormwater Master Plan, St. Albans, water

St. Albans Country Club

Cochran completed a Hydraulic Study for numerous golf cart bridges on the Lewis and Clark golf course of the County Club at St. Albans, Missouri as well as a hydraulic model of the entire drainage system utilizing HEC-RAS software.  All aspects of hydraulic modeling were performed including: analysis of each walking bridge and/or cart bridge for the 2 year to the 500-year rainfall event.

Rolling Greens Subdivision Stormwater Improvements

Festus Housing Authority

CMV-Cochran performed the surveying, grading design, hydraulic analysis, storm sewer design, retaining wall design, prepared bidding documents, performed required materials testing, construction inspection and administration services for the Rolling Greens Subdivision project.  The scope of the project included: removal of improvements; 2,097 l.f. of concrete sidewalk; 6,296 of concrete driveway approaches; mudjacking of concrete driveway panels; excavation and installation of 198 l.f. of 18” HDPE storm sewer pipe, and associated inlets and manholes; 1,069 l.f. of vinyl coated chain link fence; 245 s.f. of retaining wall; 2,069 s.y of sodding and restoration.  Four responsive contractors’ submitted bids and All Type Grading Excavating submitted a low bid in the amount of $169,898.

Moss Lane and Black Oak Drive

New first Culvert construction, Moss Lane and Black Oak Drive

City of Farmington

The City of Farmington has been a client of Cochran’s since 2012, and we have partnered to complete several projects in water, wastewater, stormwater, and transportation.  Farmington is located southwest of St. Louis in St. Francois County.  We are a proud partner of the City and have an office in the City of Farmington.

The City selected Cochran to help with an annexed subdivision stormwater issue.  The area had an existing drainage ditch that was not able to handle the amount of rainwater going through the neighborhood.  Properties were flooding after almost every rain event due to the insufficient stormwater system in place.  Originally there were two culvert pipes backing up causing flooding in two yards.  Additionally, there were two yards flooding near a bend in the ditch.

Cochran performed a stormwater study analyzing data using topographic information to evaluate an existing stormwater system and culvert pipes to see if they meet the City’s stormwater design requirements and evaluate flooding during a 100-year storm event.  Cochran performed a hydraulic analysis on the watershed tributary to the ditch and extended the study through the culvert system.  The analysis showed the first pair of culvert pipes were undersized and required replacement with a box culvert.  The next pair of culvert pipes required an additional third pipe to handle the flow.  We gave the City a report of our design recommendations to the existing stormwater system and culverts.  The topographic survey also showed the bend in the ditch required some clearing and grading to correct the flooding issue.  We then designed plans to modify the current system meeting the requirements as directed by the City.  This was accomplished by utilizing new culverts to meet design flow requirements.  Lastly, we did the bid and construction administration for the project.  Cochran was awarded the project in July 2016, and construction was completed in July 2017.