7. The following tables show apparently worthy power developments, arranged in the order of priority of their construction in a comprehensive plan for the development of the basin.

Transmission and distribution costs are not considered in the above, as this would require too many uncertain assumptions as to market. The location, name, capacity, and construction cost of the projects included in a comprehensive plan of development of the basin are shown on a general map attached hereto. (See accompanying map.) 8. A specific study in one characteristic case, and a more general study of the territory as a whole, indicates the probability that hydro development at most of these sites would be cheaper than steam development. This cannot be definitely stated until it is known what market the power is to serve.

9. A general study of the power situation, and of existing installations in Virginia and North Carolina, indicates that demand for additional power may develop in Virginia by about 1936, and in North Carolina by about 1940. Such figures are subject to revision in the light of possible new industrial developments, possible arrangem ents that could be made with existing companies, interconnection, relaying of loads, etc.

10. Flood control.-The Roanoke Basin is subject to periodic floods. A detailed study has been made of the frequency, height, and damage therefrom, including a canvass of residents and interests in the flooded area. The total area liable to overflow is 248,000 acres, divided as follows:

(a) Below Weldon on the Roanoke, 190,000 acres in a rather wide river bottom. The extent of damages varies considerably depending on the height of the flood and the season.

(b) Above Weldon on the Roanoke, 35,600 acres in a narrower valley. The topography here is such that, once the banks are topped, most of the area is likely to be overflowed regardless of height of flood.

(c) On the Dan, 22,400 acres; similar to the upper Roanoke. Practically all damages in other areas are to crops and agricultural lands.

11. The most practicable plan for protection is by levees. Preliminary studies showed that in every case the actual cost of levee construction would be much in excess of the capitalized damages, and also much in excess of the amount that experience elsewhere has shown land to be capable of carrying. Rough approximate figures for these items are given in the following table:

The following are explanatory of the above: For the Roanoke below Weldon, a floodway was assumed of reasonable size to carry the record flood without levees of excessive height. This floodway itself occupied the majority of the flooded areas, leaving only about one-third to be protected. Computations were made of the increase in height of the flood as a result of its constriction, and the levees estimated accordingly. For the two areas above Weldon, the bottomlands are so narrow that, if large floodways were designed, there would be very little ground left to protect. Accordingly, the levees were assumed to be close to the bank. Computations were not made, in this case, of the increase in flood heights due to constriction; as the cost, even on this basis, was so exorbitant that no further studies were justified. Therefore the figures are much more favorable to the project than they would be if this were done.

12. Protection by reservoirs was also studied in considerable detail, using the most favorable sites, and permitting part of the cost to be carried by power development. Since the protection would be only partial and not dependable, a detailed balance sheet cannot be set

up.

13. Channel rectification would not materially affect the situation. 14. Silt. The annual silt load at the fall line is estimated at 2,600,000 tons. Studies indicate the rate of sedimentation of 23 acre-feet per annum per square mile. This rate makes it appear that the filling of the potential reservoirs in the basin should not cause concern nor should enter into the consideration of the economics of the power sites.

15. Irrigation.-Under normal conditions natural rainfall is adequate for agriculture, and it is improbable that large-scale irrigation will ever be practiced.

16. Interrelation of navigation, power, and flood control.-Present navigation would not be greatly affected by power installations. If navigation were extended far upstream by canalization, there would be a close relation; but there is no present demand for such an extension, nor likelihood thereof in the near future.

17. There is no relation between navigation and flood control.

18. Comprehensive power development could be modified to sacrifice some power possibilities and give some flood protection. A comprehensive power development would in fact flood a large part of the bottomlands, and to that extent eliminate the question of flocd control.

19. Summary: Navigation, flood control, power, and irrigation.-The most important undeveloped potentiality of the Roanoke River is power. Given a market, a considerable amount of power could be developed and sold at a profit. This development should be considered by itself, without relation to navigation or flood control. The navigation problem is, and probably will be, confined to the lower stretch of the river; if more depth is needed, it can best be provided by dredging. The flood problem is not serious, considering the size of the basin, and cannot be solved on a large scale. Irrigation does

not enter.

20. A complete study of all potential navigation, power, flood control, and irrigation possibilities of the river has been made under the Chief of Engineers, War Department. This report is now in the office of the Chief of Engineers for further study and will later be submitted with a recommendation that it be printed.

21. Reforestation.-Over 80 percent of the Roanoke River Basin is in the region where the forest is considered to exert a major watershed-protection influence. Much of this is forested as the entire drainage has 4,812,000 acres, or 77 percent of its area, in forest cover. Part of the mountainous Blue Ridge section is now in the Natural Bridge National Forest and fairly well forested, but additional public purchases of these steep lands with shallow soil and inadequate cover should be made. In the critical piedmont plateau, the abandoned and badly ero led farm lands present a serious situation, and public ownership and reforestation are among the steps in conservation of the soil and water values of a high percentage of the lands.

22. Soil erosion.-The Roanoke River is characteristic of those southern river basins on which soil erosion has not yet assumed dangerous proportions but is nevertheless a serious problem. Its proportion of soil-saving crops with respect to other crops is about 47 percent. Locally the erosion problem is serious in spots. The remedial measures recommended by the Soil Erosion Service in its report herewith should be made effective.

23. Water supply.-Roanoke River and its tributaries carry considerable silt, the water being thus not well adapted as a source of domestic supply unless preliminary treatment through sedimentation is resorted to. Statistics indicate that at the present time some 91,500 people are served by major water-supply systems. There exist in the Roanoke River Basin as in the basins of most of the southeastern coastal streams large potential ground-water supplies which will doubtless assume greater importance with the further development of the basin.

24. Water resources investigations.-Any large-scale program of intensive development in the Roanoke River Basin will properly require additional basic stream-flow and ground-water data to supplement the information now available. The estimated cost of such river-measurement work is $12,000 and of ground-water investigations $20,000.

25. Other adjustments of land use. The problems of land use are acute. Protection against erosion demands an increase in cover crops with its attendant social and economic readjustment. (See general statement regarding Atlantic watersheds.)

ALTAMAHA BASIN

1. The Altamaha River Basin lies wholly within the eastern central and southern portions of the State of Georgia. The basin is approximately 440 miles long and averages about 35 miles in width, comprising approximately 14,403 square miles in area. The Altamaha River is formed by the junction of the Oconee and the Ocmulgee Rivers about 140 miles above the mouth The headwaters of the Oconee extend about 30 miles northwest of a line between Atlanta and Athens. The headwaters of the Ocmulgee extend to Atlanta and for 35 miles to the northeast. The upper portion of the basin lies within the piedmont region. The fall line is crossed near Milledgeville by the Oconee, and near Macon by the Ccmulgee, 145 and 205 miles respectively above the fork. An important tributary of the Altamaha is the Choopee. The basin of the Oconee comprises 5,318 square miles, and that of the Ocmulgee 6,085 square miles. The Central upland of Georgia is crossed from northeast to southwest by the Chattahoochee River, the basin of which is sharply limited along its southern portion by the Chattahoochee Ridge, which is the northern limit of the Altamaha Basin. This upland is characterized by rolling hills, with deeply cut valleys. It slopes from an elevation 1,000 to 1,200 feet above sea level to some 300 to 400 feet at the fall line. Below the fall line is the coastal plain, in which elevations above sea level are small and river valleys flat. The Altamaha empties through a delta into Altamaha Sound, 55 miles south of the Savannah River, and 22 miles north of Brunswick, Ga. The Atlantic intracoastal waterway system provides an interior water route to both Savannah and Brunswick. Darien, Ga., located on one of its mouths, is accessible to vessels drawing about 12 feet. Between Darien and the junction of the two parent streams known as "The Forks", there are no cities or towns of any consequence. The principal resources of this lower valley are timber and naval stores, with some agricultural products from the higher grounds back of the swamps comprising the flood valley.