Physical Resources
REGIONAL SETTING
CLIMATE
GEOLOGY AND SOIL
TOPOGRAPHY AND DRAINAGE
EXISTING LAND USE
NATURAL RESOURCES
WILDLIFE
REGIONAL SETTING
The City of Manchester is situated in the central part of the southwestern quadrant of Washtenaw County. This quadrant is the least populated in the county. Manchester City is approximately 20 miles from the major cities of Jackson, Ann Arbor, and Adrian. It is approximately 65 miles from the metropolises of Lansing, Detroit, and Toledo. The City provides many of the central services for the rural townships of Sharon, Freedom, Bridgewater, and Manchester.
CLIMATE
The United States Department of Commerce reports that climatic records kept at Ann Arbor indicate Washtenaw County receives an average of 30 inches of precipitation annually, i.e., 815,000 gallons per acre, of which 570,000 gallons (70%) are returned to the atmosphere by evaporation or transpiration. The rest goes into lakes, streams, and ground water recharge. Precipitation is well distributed throughout the year, with the crop season, May through October, receiving 56 percent of the average annual total.
The day-to-day weather is controlled largely by west to east movement of pressure systems across the nation. Manchester seldom experiences prolonged periods of either hot, humid weather in the summer or extreme cold in winter. Summers are dominated by moderately warm temperatures, while 81 percent of the November to March temperatures are 32 degrees Fahrenheit or below but seldom fall below 0 degrees Fahrenheit. Humidity data is available for Detroit only, with the average 1 P.M. relative humidity varying from 51 percent in May through July to 70 percent in December. The percent of possible sunshine varies from 70 percent in July to 32 percent in December and January, and averages 50-54 percent.
GEOLOGY AND SOIL
The topography of Washtenaw County was shaped by continental glaciation. The western townships are generally sandy, characterized by linear hills, humpback ridges, and kettle-holes. The bedrock and terrain slope irregularly from the northwest to southeast toward the ancient lake bed.
The soils deposited in the vicinity of Manchester City are of the Fox-Boyar-Fox variant association. The Soil Survey of Washtenaw County, Michigan states: “The nearly level to moderately steep, well-drained soils have a moderately fine textured or moderately coarse textured subsoil and coarse textured underlying features.” The soils are sandy loam or loamy sand. Loam is a rich soil composed of clay, sand, and some organic matter. TetraTech MPS, the Village engineers, describe the Village as lying on the interface of the Marshall Sandstone and Coldwater Starts.
The Soil Survey also includes detailed maps of specific soil types overlaid on aerial photographs of small sections of the county. Text and charts describe erosion hazards, probable runoff, predicted crop yields, management concerns, suitable trees, and potential for wildlife habitats.
TOPOGRAPHY AND DRAINAGE
Manchester City is in the Washtenaw County highlands, thus part of the main ground water recharge area in western Washtenaw County. The City is within the River Raisin drainage basin. Continuous stream flow records have been kept since 1969 at station #04175600. TetraTech MPS reports the drainage area above the station is 132 square miles. Only two small towns, Brooklyn and Cement City, are located upstream, so the water quality of the River Raisin is very good as it flows into Manchester en route to Lake Erie.
The ground water table varies within the City depending upon the ground surface elevation relative to the water surface. Generally, the ground water level varies between three and ten feet below the ground surface.
The City Planning Commission describes local terrain throughout the two square mile area as “generally rolling with drainage oriented toward the Raisin River”. The highest point in the City is located in the extreme southwest corner at an elevation of 980 feet above sea level. Other high areas occur in the northeast corner (approximately 960 feet above sea level) and at Ann Arbor Hill near M-52. The lowest point is found on the bank of the River Raisin where it crosses the east City limit. Elevation at this point is approximately 850 feet. The 130 foot difference between high and low points within Manchester illustrates the rolling character of the terrain, as does the fact that the River Raisin experiences a 40 foot drop in elevation in its passage through the Village.
Excessive slopes are found primarily in three general groups: in the northeast corner, in the southwest corner, and in close proximity to the banks on the River Raisin.
Low-lying or poorly drained areas are found in the southern portion of the Village, in the northwest corner, in the northeast corner, and in the flood plain area of the River Raisin.
EXISTING LAND USE
Table 1 was surveyed and computed by the Washtenaw County Metropolitan Planning Commission’s staff in the summer of 1970 and has been updated since that time by local planners as land has been added to the Village and new developments have taken place.
TABLE 1
- Land Use Total Acres % of Total
- Residential
Agriculture (AG) 88.42 8.29%
Single-family (R-1A &1B) 675.31 63.34%
Multiple-family ( R-2 & R-3) 20.80 1.94%
Mobile-home (MHP) 18.17 1.70%
Planned Unit Devl (PUD) 125.29 11.74%
- Residential
Commercial (C-2 & CBD) 17.88 1.69%
Local Service (C1) 4.95 .46%
Industrial (I-1 & I-2) 115.31 10.77%
Total Zoned Acreage 1066.13 acres 100%
Community Facilities
School 154.32
Church 1.22
Recreation 31.30
Public & Quasi-Public 10.50
197.34
Transportation
Parking 11.40
Street & Roads 154.81
166.21
Approximately 50 percent of the total City acreage is presently developed. The remaining 50 percent is classified as agricultural, wooded, vacant, and river surface.
NATURAL RESOURCES
The River Raisin is the most important natural resource in the City. It flows through the residential areas and the central business district from the northwest to the southeast. It previously ran the turbine at the mill and provides scenic beauty, nesting and feeding areas for wildlife, and sites for some recreational activities.
In 1973, the Washtenaw County Metropolitan Planning Commission mapped the major woodcuts (more than 40 acres) and major wetlands in the county.
WILDLIFE
The many open and undeveloped spaces in Manchester provide inviting habitats for a variety of wildlife. The woods and fields host a variety of animals such as rabbits, squirrels, opossums, raccoons, skunks, rodents, fox, deer, quail, pheasants, hawks, owls, and songbirds. The river areas also attract an assortment of wildlife, especially ducks, geese and blue heron. There is a large fish population in the two impoundments of the River Raisin.
TetraTech MPS has reported that the banks of the River Raisin just east of the Village provide the prime habitat of a snail, Pomatopsis Cincinnatiensis, which is important in the study of Schustomiasis. The soil from the riverbank is used to raise these peculiar snails in medical laboratories all over the world. In addition, the river is home to a rare fish called the “silver shiner.”
