The Aurelius and Delhi Consolidated Drain Drainage District serves 2,747 acres of Ingham County including 1,451 acres of Aurelius Township and 1,296 acres of Delhi Charter Township. In total, the Drainage District encompasses 275 residential and agricultural properties.
The primary focus of the Project is to reduce flooding of county roads and the adjacent residential and agricultural land in the upper portion of the Drainage District. Most of the flooding is located near the intersection of Nichols and Eifert Roads. Nichols Road east of the intersection with Eifert Road is subjected to regular flooding for long periods of time due to lack of an outlet for the water and locally heavy soils. To quantify the duration of flooding and existing hazardous road conditions, the residence time is great enough to regularly allow ice formation over the asphalt road surfaces during the winter months and create flooded conditions during other months. Affected properties in the flooded areas, all of which are served by septic systems and wells, currently have ponding for days and even weeks.
To determine a solution to the flooding problems, a hydraulic sanitary and storm sewer analysis (SSA) model was created in conjunction with an open channel Hydrologic Engineering Center’s River Analysis System (HEC-RAS) model. The models were utilized to illustrate existing conditions and model several proposed solutions. A refined solution was obtained minimizing the cost and maximizing the flood control benefit of the proposed system. The solution assures the 100 yr 24 hr storm, 5.3 inches of rainfall, will not overtop Nichols Road and that the residential flooding is limited to a 6-hour duration in a 4-inch rainfall event (25 yr 24 hr storm event).
To alleviate the flooded areas near the roads and road intersection, 2.2 miles of storm sewer will be installed, 1,580 linear feet of existing storm sewer will be removed and replaced with a two-stage meandering channel to lower the hydraulic grade line by nearly two vertical feet, and 69 drainage structures will be installed to collect surface water (Including 3 structures to regulate surface water elevations in existing wetlands). The infrastructure improvements will provide a drainage outlet for the approximately 336 acres of the upper portion of the Drainage District. To better convey this flow and to better serve District properties, the existing main channel from its outlet near the Grand River to the beginning of the new drain construction will be cleaned out and cleared.
In addition, trenching to construct the storm sewer will result in the restoration and improvement of approximately 3,700 linear feet of Nichols and Eifert Roads. Eifert Road serves as a primary road for Ingham County. This road restoration includes the repaving of the intersection of Nichols and Eifert Roads. Roads will be closed to through traffic during the construction period. A detour plan has been coordinated with the Ingham County Road Department to assure that traffic is properly maintained within the vicinity. All efforts will be made to minimize inconvenience to residents and travelling public.
To accommodate the additional discharge from the intersection area, 14 culverts are being improved (upsized) and 2 are being removed along the existing main channel of the Aurelius and Delhi Consolidated Drain. Many of these crossings that need improvement are old and in poor condition anyway. Among the 14 improved culverts, is the Onondaga Road culvert. Onondaga Road serves as a primary road for Ingham County.
Construction of the Aurelius and Delhi Consolidated Drain Project started in the spring of 2019. The assessment for the Project would begin in 2019, and be levied over twenty years.