| OCR Text |
Show TABLE 1.-Characteristics of the principal tributaries of the Tennessee River River Length Drainage basin area Average unregulated flow Maximum recorded flow Minimum recorded daily natural flow Fall, headwaters to mouth Clinch.................... River miles 351.6 217.7 143.9 277.5 144.6 Square miles 4,413 5,124 2,700 3,776 2,627 Cubic feet per second 4,100 at Norris Dam............. 6,700 at Douglas Dam........... 1,900 at Hiwassee Dam.......... 4,600 at Cherokee Dam.......... 3,700 at Fontana Dam........... Cubic feet per second 128,000 150,000 80,000 150,000 129,000 Cubic feet per second 200 370 140 500 420 Feet 1,610 1,390 2,220 1,940 1,440 French Broad.............. Hiwassee.................. Holston... ........... Little Tennessee........... All of these tributaries have wide variations be- tween maximum and minimum flow, the maximum recorded flow being several hundred times the mini- mum in all cases. Minimum flows of 500 second- feet or less have been recorded on all five streams, all of them in 1925. All have appreciable heads for power. The fall of the Hiwassee is more than 2,000 feet from its headwaters to its confluence with the Tennessee. The combination of moderately high rainfall and steep gradients are favorable to hydro- electric power development. However, the wide fluctuations in flow make conservation storage es- sential. Local cloudburst storms occur throughout the Tennessee Valley. In the southeastern mountain area very heavy rainfall is also experienced during tropical hurricanes. Runoff after such storms has been large enough to cause havoc on small streams, AVERAGE ANNUAL PRECIPITATION Tennessee River Basin FIGURE 1. Under 40 inches 40-50 5O-60 60-70 70-80 Over 80 Source: Tennessee Valley Authority 712 |
