Under these circumstances the State of Ohio, in section 408-3, General Code, states that "The Ohio Water Resources Board shall (b) be authorized to cooperate with and negotiate for the State of Ohio with any agency of the United States Government or agency of any other State pertaining to the water resources of the State of Ohio."

And "(d) Within the limits of the appropriations granted to it, assist in an advisory capacity, any properly constituted conservancy district, municipality or other government agency of the State of Ohio in the planning of works for ground-water recharge or the establishment of water-conservation practices."

Then to make this cooperation possible, the law provides, in section 408-5, the Ohio Water Resources Board may accept gifts, contributions, devises, and bequests of money or property and use or expend the same, or their proceeds, in carrying on its work, as provided in sections a, b, c, and d of section 408-3, without conveyance to the State or payment to the State treasurer; but in the event of any such gift, devise, or bequest, the board shall appoint a treasurer and require of him an appropriate bond, which shall be filed in the office of the secretary of state. Any political subdivision in the State shall have power to make contributions to the board.

These statutes make it possible to develop, by cooperation with the Federal Government and the State, a much more comprehensive water-conservation program than was possible 11 years ago when the conservancy district was organized in 1934.

Respectfully submitted.

DAVID C. WARNER,

Water Conservation Consultant in the Department of Public Works.

NOVEMBER 14, 1945.

RESERVOIRS IN THE SANDUSKY WATERSHED

To the DIRECTOR OF PUBLIC WORKS:

In order to properly protect the cities and towns along the Sandusky River and provide a better normal flowage, it will be necessary to control and retard the floodwaters in the upper stretches of the river by the use of controlled and detaining reservoirs at certain points below the Summit Reservoir that can be completely regulated so as to release a minimum of floodwater down the main channel.

The Summit Reservoir would control about 250 square miles of the upper Sandusky River above the main dam, that should be located at a point about 1% miles below the village of Little Sandusky.

The Summit Reservoir with a conservation pool at 890 feet, mean sea level, and the flood storage up to 900 feet mean sea level, would inundate the whole village of Little Sandusky, that would have to be moved out of the reservoir area.

The upper part of the drainage basin of the Tymochtee Creek in the amount of about 100 square miles would be controlled by a dam and levee near the village of Marseilles.

This Marseilles Dam could be used as the emergency spillway or safety valve for the Summit Reservoir draining into the Tymochtee Creek Valley, where two detaining reservoir sites could be developed that would hold the excess floodwaters out of the main channel, where other streams are flowing into it from the east.

The Tymochtee Creek flows into the Sandusky River at a point about 12 miles south of Tiffin and has a drainage area of 299 square miles.

The drainage area of the Sandusky River at the confluence of the Tymochtee Creek has a total drainage area of 652 square miles out of its complete drainage basin of 1,421 square miles.

Up to this point the floodwaters can be controlled for a minimum flood flow by controlled reservoirs. They will be described later.

The topography of the watershed above this point is such that reservoir locations can be developed to control a very large percentage of the run-off of excessive floods.

Below this point the Sandusky receives three fairly large tributaries, namely, the Wolf Creek of 153 square miles, the Sycamore Creek of 68 square miles, the Honey Creek of 177 square miles, and several other small streams.

The Sycamore and Honey Creeks enter the Sandusky River above Tiffin where the total drainage area above that city is 965 square miles.

The Wolf Creek joins the Sandusky River at a point about 6 miles south of Fremont and drains a terrain of an undulatory ground morainal character with no favorable locations for large storage reservoirs.

The main control of Wolf Creek will have to be delivered by a system of soilconservation districts, with well-controlled drainage, and farm ponds and with improved farming practices throughout this excellent farming area and probably a few slack-water pools in the main channel of the creek to slow up and retain the run-off.

As was mentioned in my first report, this part of the State lies in the glaciated section, and will necessitate the close cooperation of the Soil Conservation Service Division of the United States Agriculture Department to coordinate their survey with the United States engineers in a resurvey of the Sandusky watershed for flood control and water conservation.

This subject of improved farming practices for upstream engineering, that Congress has assigned to the United States Soil Conservation Service, involves and necessitates the close cooperation of the soil-conservation districts in all of the counties of the Scioto-Sandusky Conservancy District, so as to retain the maximum amount of soil and water on the farms, where most needed, instead of augmenting the flood damages.

Every little bit helps, either for or against flood control throughout the whole watershed.

The necessity of keeping these wasting soils and water on the farms, where they originate and are so valuable, can be illustrated by an outrageous example of the Columbus water famine of February 1945, when it was reported that O'Shaughnessy Reservoir had lost 18 percent of its capacity from silting.

This 18 percent of displaced water storage represents 6,500,000 tons of silt, sand, and gravel that has lodged behind the dam as a result of flood erosion from the 640,000 acres of the watershed of the fine central Ohio farms above O'Shaughnessy Dam. In other words, these 640,000 acres have contributed more than 10 tons per acre of topsoil during the 20 years of the existence of this reservoir; besides that unknown amount that flowed over the top and down to the Gulf of Mexico in the yellow floodwaters during those 20 years.

The prevention of this erosion is a very important part of the Scioto-Sandusky flood-control plan that must be considered as a part of the engineering development.

This farm-land erosion menace has been recognized by the United States Congress and since 1936 has been included in all of the Federal flood-control laws with appropriations to the Soil Conservation Service for cooperation with the United States engineers' flood-control projects.

This soil-conservation service has been mentioned in connection with Wolf Creek, because that is the main type of flood control that can be used on that agricultural watershed, but every tributary of both rivers has the same problems to be solved in their own peculiar manner for improved farming practices, even to the reforestation of the shore line of each storage reservoir, down to the conservation-pool water line, with those trees that can resist flooding for short periods, when the top-flood pool is storing the necessary amount of detained waters away from the dangerous crests that would damage the valley below. The flood-resisting trees for planting the flooded shore areas that are above the conservation pool are very useful as pulpwood, such as the poplar, willow, and birch families.

The Summit Reservoir will control about 25 percent, or 350 square miles out of 1,421 square miles, and these summit floodwaters can be regulated so as to deliver a very small addition to the oncoming flood crest as it proceeds down. stream toward Tiffin and Fremont or with the proper timing and regulation the effects of these headwaters can be reduced to zero, by retaining them or holding them in storage until the streams below have run out or spent their crest.

A smaller reservoir at upper Sandusky to act as a detaining storage on top of a conservation pool that could be used by the city for industrial and domestic water supply will help to slow up the crest that would pass into the next basin to be slowed up still more before the river receives several small tributaries near the village of Mexico. This retarding dam should be located in the Sandusky River just above the confluence of Tymochtee Creek.

There are two good locations in Tymochtee Creek where retarding dams can be built with small conservation pools in the stream bed for recreation and local farm water during drought periods.

The Sycamore Creek joins the river near the village of Mexico with 68 square miles of drainage area, that should have some small reservoirs for regulation of a retarded flowage with conservation pools for local low-water benefits.

Downstream near the corporation line of Tiffin could be located a dam in the Sandusky River that would set the water back upstream to upper Sandusky and also up Honey Creek for retardation above Tiffin. Then in the flood storage backwaters of Honey Creek is a good location for another retarding basin with an excellent opportunity for a conservation pool that would be very convenient as a feeder to an augmented water supply in the Tiffin Reservoir and an excellent recreation lake for that community.

All of these conservation pools could be feeding an augmented low-water flowage down through Tiffin and Fremont for industrial water supply and pollution dilution so that better industrial development for these communities can be anticipated.

The foregoing suggestions are made to the conservancy district with the suggestion that detailed engineering studies should be made by a district chief engineer to determine all the values, costs, and benefits that, according to the latest Federal flood-control law, will become a part of a resurvey of the SciotoSandusky Watershed Conservancy District report to the Flood Control Committee of Congress by the United States Army engineers.

Respectfully submitted.

To the DIRECTOR OF PUBLIC WORKS.

DAVID C. WARNER,

Water Conservation Consultant, Department of Public Works of Ohio.

FEBRUARY 11, 1946.

1. Mr. Philip Burgess, consulting engineer, Columbus, Ohio, in a letter to Mr. Del Starkey, secretary, Columbus Chamber of Commerce, desires clarification of some of his understandings of the problems of the Summit multiple-purpose reservoir to control the headwaters of the Scioto and Sandusky Rivers for flood control and water supplies both ways on these two rivers through central Ohio. 2. The drainage area above the reservoir from both watersheds is 770 square miles from the Scioto and 350 square miles from the Sandusky. The reservoir will be located on the Sandusky side of the divide, but the Scioto floodwaters will be diverted across the summit by a channel with a bottom width of 300 feet and excavated to a depth on at least 885 feet, mean sea level, which would be 5 feet below the conservation-pool surface of 890 feet, mean sea level. The total capacity of the top 5 feet between 890- and 885-foot levels would be 105,000 acre-feet of storage with a full conservation pool at 890 feet, mean sea level, at the beginning of a supposed 8-month drought period.

3. Assuming that a drought year of only 24 inches of rainfall is precipitated on the headwaters of these two rivers of 1,120 square miles and that two-thirds of 24 inches equals 16 inches, represents the rainfall for the 8 months of drought, and that only one-eighth of 16 inches, or 2 inches, would represent the run-off into the storage reservoir, and since 30,000 acres is 47 square miles, or the area of the lake, and that the rainfall on the lake is a part of the evaporation in the full amount of the 16 inches, or 1% feet, off from a surface of 30,000 acres, it would equal 40,000 acre-feet evaporation.

4. Since the annual evaporation of this central part of Ohio is assumed to be 30 inches instead of 26 inches as is recorded by the USGS at Columbus for the an30" nual evaporation from the surface of a lake or pond; thence

365 days

-0.0822''

per day average, then assuming that a drought evaporation would be 0.1 inch average per day and during the 240 days, or 8 months, three would be 24 inches total from which we must subtract the 16 inches of rainfall that falls directly onto the surface of the lake, which leaves 8 inches or two-thirds of a foot from surface, or 20,000 acre-feet for evaporation out of the total storage of the top 5 feet of the reservoir, or 105,000 acre-feet of draw-down for water supply.

5. During low-water flow in these two rivers, it is desired that their flowage should have a minimum of 200 cubic feet per second down the Scioto and 50 cubic feet per second down the Sandusky, or a total of 250 cubic feet per second per day during the 240 days of drought, or 500 acre-feet per day, that would represent a demand of 500X240=120,000 acre-feet plus the 20,000 acre-feet of

evaporation of direct loss, or a total of 140,000 acre-feet demand from the conservation pool. But it has been calculated that the lake would receive 2 inches of run-off from the watershed outside of the reservoir surface area, which 686,720 acres X 2" would be 1,073 square miles, or -=114,453 acre-feet of run12 off into the reservoir that must be added to the 105,000 acre-feet, or a total of 219,000 acre-feet, from which must be subtracted the 140,000 acre-feet, leaving a surplus of 79,453 acre feet that would have to be regulated for a fair disposition down the Sandusky River, that would more than take care of any riparian rights of diversion of water from the Sandusky watershed, where the Scioto excess waters had been stored in the Summit (Sherman) Reservoir for headwater flood control and multiple purposes.

6. But in case the flowage in the Scioto River, the Sandusky River, and the Tymochtee Creek stopped altogether, as they did in the months of January and February 1945, when Columbus had the water famine, and the Sherman Reservoir would be drawn down to 885 feet, mean sea level, so that no water could flow down the Scioto diversion channel; then at that point there would still be 40 feet of water behind the Bellepoint Dam, or about 16,000 acre-feet of storage with the O'Shaughnessy and Grigg Reservoirs full to the lip of the spillways, because they had been kept full by the draw-down of Sherman Reservoir.

7. Supposing that this happened and that Columbus had grown to that population where it was using 120 cubic feet per second, instead of 60 cubic feet per second, then Bellepoint alone to be drawn down to the bottom, could supply that amount for 66 days and still have the other two reservoirs full of water to be drawn from for another 100 days or until the rains came.

8. The Sandusky would at the same time be getting the normal supply of water from the Sherman Reservoir, because that dam would still have 65 feet of water behind it in the lake, not calculating any influent from the surrounding water table.

9. The seepage into the water table here on the summit of the State is one of the benefits that heretofore has not been evaluated in the ratio of benefits against costs per annum and as yet without any ground-water survey data from this part of the State, there are no criteria for accurate calculation of annual seepage or infiltration to the water table. It is a known fact that a flood will thoroughly saturate its flood plain and cause a considerable rise in the surrounding water table. Thus as the floodwater of the Sherman Reservoir would spread out toward the 900-foot mean-sea-level contour, the shores of the conservation pool would become saturated for great distances from the lake and the surrounding water table would be replenished to an extent that can be calculated only after a survey of the existing water table, as it will be before the lake starts filling, and then by a gaging of the rise and fall of the water table after the lake has been filled and flood and drought periods come and go, to be recorded on the automatic gages that are now being installed by the Ohio Water Resources Board.

10. There will be a temporary loss of water from the reservoir by seepage or percolation into the summit water table while the lake is filling with floodwater, but when that water table or saturated zone rises to or above the level of the permanent conservation pool throughout the surrounding country, then whenever the lake starts to recede and drop below the surrounding shore-line water table, there will be a seepage or refiltration back into the lake in springs to replenish the surface drop or loss from either evaporation or withdrawal. This amount of refiltration is an unknown quantity from the 200 miles of shore line and is very hard to calculate without any exact data, just like the ground-water infiltration would be in the first place, when the water table was filled and would be kept full during floodtime saturation. Therefore, it would be wise to ignore both the losses and gains from infiltration and refiltration, from and to the reservoir. The one will about equal the other, though, over a long period of time, the restored ground-water reservoir will yield the greater values as an economic assets and the benefits of a rejuvenated water table to the surrounding country below the level of Sherman Lake on the summit of the State, will be beyond calculation.

11. Since Columbus uses an average of about 40 million gallons daily or 60 cubic feet per second, the city would not need to draw off the full amount of 200 cubic feet per second, but only enough to supply the water works and a limited amount, say 120 cubic feet per second to mix the surplus with the Olentangy

flowage to be released from the Delaware Reservoir, so as to create a proper dilution of the pollution of the Scioto River below the city sewage-disposal plant. 12. The United States Engineers, who will have control of the draw-down or regulation of the storage waters, would be able to calculate the amount of water needed for city water supply and sanitary flowage in these rivers at all times. They would thus be able to regulate their control gates according to the emergency and act accordingly for the community welfare and usage.

13. When these reservoirs are built, they will be operated by the United States Engineers as units in the regulation of the control of both floods and low-water flowage for navigation and other purposes on the Ohio and Mississippi Rivers.

14. When the conservation pool is drawn down to any great extent below the normal water line, then the gradient of the water table will be increased according to the depth of draw-down and the increasing gradient toward the new water line will multiply the velocity of the influent or refiltration toward the reservoir at all points around the shore line, so that there would be an incalculable replenishment of the reservoir, that will have an unknown influence, resulting from the amount of available stored ground water in the newly rejuvenated high water table.

15. The surrounding replenished water table is an integral part of the reservoir and is always available for replenishment when needed to flow back into the reservoir during drought. This is a law of nature that maintains the normal flowage of all streams during the drought periods until the available ground water is drawn down to a point where it will no longer seep into the stream or lake by gravity. This condition prevails clear up to the headwaters of every stream that is tributary to the reservoir throughout the entire watershed that is feeding the run-off into the lake even to the underflow that is flowing under the gravels in the bed of the stream.

16. These characteristics of ground-water flowage are the compensating conditions that keep our springs and streams flowing during drought periods. This law of nature makes it imperative that improved farming practices of contour farming and farm ponds must be developed throughout the headwaters, so as to replenish the ground water and retard the run-off long enough for the rainfall to have time to penetrate into the water table. This overflow of the ground waters down grade from the hill farms is the salvation of the constant flowage from the small streams that creates the constant normal low-water flowage of the great rivers.

17. The Soil Conservation Service, in the soil-conservation districts in the Scioto-Sandusky Conservancy District, will perform a valuable part in both the flood control and water supply development, by retardation and rapid percolation, with prevention of erosion and silting of the storage reservoirs.

18. For all of these reasons, it is very important that this part of the Federal flood-control laws be recognized and that soil conservation be given its proper credit as an integral factor in flood control for an estimated retardation of flood run-off and ground-water storage in the ground-water reservoir.

19. All of the counties in the conservancy district are not yet organized, but the counties that contain hill topography are rapidly being organized into soil conservation districts and should be given credit for their proportion of estimated benefits for proposed programs in the flood-control program for the watershed.

20. This development of upstream engineering will contribute many floodcontrol benefits that up to this time have not been a part of the United States Engineers calculations of benefits against costs of flood-control projects, such as flood run-off retardation, ground water reservoir replenishment by percolation, the prevention of erosion with excessive silting resulting in the loss of storage in the reservoirs caused by the overloaded flood waters that are burdened with the erosion debris from farms that do not practice soil conservation. 21. It is very encouraging that both of these Federal agencies have been coordinated in this new science and practical practice of water and soil conservation and flood control, so that these criteria are rapidly developing whereby both agencies can show benefits and known values.

22. The development of these criteria during the last two decades for both headwater flood control by reservoirs and upstream engineering by soil conservation methods of improved farming practices, have progressed by practical experiences in intensive studies and construction, so that today these two Federal agencies that have been coordinated by authorization of Congress are able to work together on the same watershed and combine their estimates of benefits into a much more accurate calculation of direct results.