Minnow Pond Drain Phase 3
City of Farmington Hills Minnow Pond Drain Introduction: The Minnow Pond Drain Phase 3 Project is located in Oakland County in the S.W. of ¼ of Section 4, T. I N., R. 9E, City of Farmington Hills and is situated north of Thirteen Mile Road and east of Drake Road. The project included reconstructing a portion of the original Minnow Pond Drain. Free holders of lands in Farmington and West Bloomfield Townships established the original drain in 1899 through application to the Drain Commissioner. The length of the drain was 14,419 feet and subsequently was constructed in 1901 as an open ditch. Although the entire Minnow Pond Drain lies within the City of Farmington Hills, portions of the drainage district include areas in West Bloomfield Township, Commerce Township and the City of Novi. In the mid 1800's to early 1900's, development in Farmington Hills, then know as Farmington Township, was generally sparse and land use was primarily agricultural and included grain and dairy farming. It is assumed the original drain was petitioned to drain adjacent open farmlands as well as for public health and welfare of landowners within the drainage district. After World War II, Farmington Township, as in many areas of southeast Michigan, experienced a dramatic increase in growth and development. Subsequently in 1973, the Township was incorporated as the City of Farmington Hills. Also during this growth period, changes occurred along the open channel of the Minnow Pond Drain, whereas former open land areas were now developed into residential subdivisions with lawn and landscape areas bordering the open channel of the drain. In addition, residents constructed small dams and retaining walls for the purpose of creating impoundments in several locations along the drain. These non-permitted impoundments impeded flow through the drain and ultimately filled the original channel with silt. The intent of the new project was to clean out and reshape the silted channel, remove three illegal dams, stabilize the channel banks, construct one low-head dam, and improve the hydraulic capacity of the drain channel. Also, as the drain is located in a scenic area, it was important to retain the aesthetic features of the watercourse. The Minnow Pond Drain Phase 3 Project, was the last phase of a $10,000,000 Minnow Pond Drain drainage program petitioned pursuant to provisions of Chapter 20 of the Drain Code by the City of Farmington Hills to the Drainage Board in June 1990. The Phase 3 construction contract was awarded in November 1998, with construction beginning in April 1999, followed by project completion during fall 1999. The construction cost for the Phase 3 project was approximately $675,375.00. The project included 1800 lineal feet of open channel cleanout and reshaping, approximately 1200 syd of natural boulder armoring, 2800 syd of limestone rock fragment armoring, 1500 lineal feet of stone header, removal of three existing dam structures and miscellaneous rip-rap, construction of a low-head dam, and restoration of disturbed areas. Many challenges were inherent with both design and construction aspects of the project, as a high ground water table combined with poor soil conditions in an active water course were less than favorable for supporting the heavy construction equipment required to do the work. Also, residents were not comfortable with the potential massive earth disruption, which could occur in their back yards. Special techniques were required for construction staging and access, material deliveries, by-pass pumping of drain flows, soil erosion and sedimentation control, bank stabilization and excavation. Public Involvement Due to the sensitivity of constructing the project through a scenic residential neighborhood, several public informational meetings were held with residents living along the route of the drain. Project representatives in attendance-included staff from the Drain Commissioners Office, the City of Farmington Hills and the Consultant. In addition, meetings were held with individual residents for the purpose of obtaining construction easements. Environmental Water Quality Benefits The quality of the drain prior to construction was marginal, as some areas were overgrown with brush and lacking a defined channel. Other areas were very shallow with the presence of stagnant water and odors. In locations where the channel was open, the constricted channel section experienced bank erosion. Improvements to the drain included channel excavation to depths approaching five (5) feet to discourage weed growth within impoundment areas. Channel banks were stabilized with a combination of geotextile fabric and natural boulders or rock fragment to prevent bank erosion. A low-head dam with an overflow weir was constructed to maintain desired water depth. Portions of the entire channel were lined with geotextile fabric and large natural boulders to prevent scour. Also, the overflow weir and rock channel lining assist in aerating stream flows for water quality enhancement. A sediment sump and open graded rock dam were placed at the downstream end of the project where it transitions to the existing drain channel. This sediment control measure prevented siltation from migrating downstream during construction. Use of New Technologies The design of the Minnow Pond Drain evolved from the City of Farmington Hills Storm Water Master Plan, which was adopted by thCity in 1982. The Master Plan identified methods by which to minimize flooding problems under existing and future development. The flow rates for the Minnow Pond Drain were calculated under existing and proposed conditions based on a fully developed drainage district as derived from the City of Farmington Hills "Master Plan for Future Land Use." New technology included the utilization of several computer models in determining flow rates and flow distribution for the various branches of the drain. The runoff hydrographs that were derived in the design of the Minnow Pond Drain were calculated by the hydrology program 'ILLUDRAIN" (Illinois State Water Survey's Hydrology Section). Water surface elevations were calculated using the "HEC-2" computer program. The flow rates generated by "ILLUDRAIN" were input into HEC-2 and profiles were developed along the drain under existing and proposed conditions. Innovation Utilization of excavated sumps within several locations of the drain channel combined with by-pass pumping of drain flows allowed excavation and cleanout of the. Existing channel to occur without producing excessive sediment transport to downstream areas. In addition, a sediment trap and open graded rock dam were placed at the transition to the existing drain to further eliminate and control sediment transport downstream. Spoils required handling several times to minimize disturbance to the unstable channel banks. The moisture laden excavated spoils were temporarily stockpiled away from the drain bank for dewatering and consolidation prior to transporting offsite. This measure prevented migration and return of the spoils to the completed portion of the drain. Special construction mud mats were utilized for support of construction equipment along the route of the drain thereby minimizing the potential for major earth disruption. Rock fragment was placed along the banks of the drain, above and below the normal water level. Some channel locations were fully lined with natural boulders. Geo-textile fabric was placed beneath the rock in all areas to prevent scour and undermining of the rock. Complexity In addition to the complexity of engineering and construction issues as stated in the Innovations summary, there were significant efforts required to gain the confidence of property owners residing along the drain to grant the necessary easements for construction. Although most residents were ultimately in favor of the project, three property owners declined to grant any form of easement. These properties were located at the approximate mid-point length of the drain. A determination was made to forego condemnation procedures and subsequently 300 lineal feet of improvements were deleted from that portion of the drain. Cost Effectiveness In June 1990, the City of Farmington Hills petitioned the Drain Commissioner to establish the Minnow Pond Drainage District as a Chapter 20 Intra-County Drain. As a result of this action, the original Minnow Pond Drain, which was completed in 1901, was included in the new district. In accordance with Chapter 20 provisions, property owners along the route of the drain project will not receive direct assessments, as the municipal corporations within the drainage district will be obligated to levy taxes at large if so needed www.ABE-ENGINEERS.COM Detroit: 313-961-5170