Water resources of the River Raisin basin, southeastern Michigan

The accompanying tables summarize some physiographic data for selected subbasins in the River Raisin basin having about 2 or more square miles of drainage area. Selected subbasins of the major streams include area above mouths of tributaries, and points of interest such as highways, towns, gaging stations, or dams, and below the confluence of the main stream and a tributary so as to include both drainage areas. Similar criteria were used for tributary streams, except where the tributary was too small to merit further dividing. Most subbasins are shown on the basin map, sheet 1. To help locate the tabulated areas on the map, each subbasin is assigned a number and numbers for selected subbasins are shown on the map at the downstream end of the subbasins. Also shown are names of main roads and river miles, at 5-mile intervals, for the River Raisin and two of its main tributaries. Basin divides were outlined on the latest 7Vi-or 15minute topographic maps, scale 1:24,000 or 1:62,500, respectively, and drainage areas determined in accordance with the standards set forth by the Committee on Hydrology, Water Resources Council (formerly the Subcommittee on Hydrology, Inter-Agency Committee on Water Resources). Similarly, river miles were determined in accordance with the Committee's standards. Mile zero is considered to be the mouth of the stream. The source of a stream is considered to be the upper end of the stream, whether or not it is perennial. A defined channel which may be inferred from topographic maps to carry water occasionally is, therefore, included in the stream length. A stream that has its beginning at the confluence of two tributaries is considered to be a continuation of the longer tributary and to have as its source the source of that tributary. Its average slope is determined by treating the stream and tributary as one. Beaver Creek (number 253), for example, is considered to be the continuation of Slater Creek. In the table Slater Creek has been parenthetically noted as being the headwaters of Beaver Creek. Other tributary streams, in tl ;s classification, are likewise noted. Altitudes shown for site and source are f:~om topographic maps and represent the altitude of the water surface at approximately normal river stage, the datum being mean sea level. Average slopes were computed from the mileage between and differences in altitude of site and source and represent the fall of the stream in feet per mile. Streams are listed in a downstream order along the main stem, with tributary streams entered above the next main-stem location. A similar order if followed for listing streams of first rank, second ran) \ or other rank. To indicate the rank, and the stream to which it is tributary, the stream name is indented, each indentation representing one rank. The st"aam rank is further identified by numbers in th* column heading with stream name and location. Number 1 applies to River Raisin. Principal tributaries are under number 2, their tributaries under number 3, and so on.