of much attention and comment, and the City Engineer and his assistant, from a crude gaging made at the dams above, estimated that about 100 cubic feet per second was then passing over the falls.

Some of those present called attention to the traditions that beds of quick sand had been found in early days when attempting to tunnel for a railroad through a portion of the rim of the proposed basin and the site of this supposed weakness was carefully noted for future investigation.

The object to which attention was primarily directed by the city officials was that of relief from floods, but investigation of the extent to which the water power of Rochester could be augmented by the release of this stored water was also requested.

Attention was also directed to the reputed suggestion of the late Lord Kevlin, the eminent physicist, on the occasion of his visit to Rochester some years ago, in course of which he is reputed to have suggested that the desired storage and flood control could perhaps best be developed by a series of small reservoirs on the tributaries of the Genesee river, rather than by the construction of a large reservoir either at Portage or Mount Morris.

Although it had at first been considered that the investigations desired on the upper Hudson would consume all the time and all of the appropriation available, it appeared eminently proper that some portion of the time and funds be devoted to the study requested by Rochester, especially so since two widely separated portions of the State would thus each have a local interest in the question of the development of great water powers under State control.

All previous records relating to this matter in the reports of the State Engineer, the State Water Storage Commission, the Rochester Flood Commission, together with the data in the volume published by the Board of Regents concerning the Hydrology of New York and the publications of the U. S. Geological Survey, were searched for data, in order that the smallest possible expenditure in surveys and borings might serve the present purpose.

It is of interest in passing to note that no specific plan of power development at the Genesee Falls near Portage was made in the Rafter report of 1896 or in his N. Y. Hydrology. The estimates

of power there presented refer only to the increase at the present power sites within the city of Rochester.

USE OF RESERVOIR FOR FLOOD CONTROL.

Advantages of State Supervision.

On the Genesee river, the construction of a great storage reservoir has been repeatedly urged during the past ten years. The reason which has appealed most strongly to the public is that this would lessen the flood dangers at Rochester and lessen the overflow all along the remarkably level, broad valley through which the river winds for forty miles between Mount Morris and Rochester. It has also been made plain that this reservoir could be made to add largely to the water power of the present factories and power stations at Rochester.

In the final analysis, it now appears that the greatest good to the State at large and to the city of Rochester in particular, from storage reservoir construction, will be found in power development rather than in flood control, for the two purposes are to some extent antagonistic. The full reservoir is best for power. The empty reservoir is best for holding back a flood, but both purposes can be combined to some extent and to do this has been one object of the present study.

The Portage reservoir project is a large one and involves invoking largely the use of the State's right of eminent domain, in the taking of farms and in the moving of homes, although as such matters of reservoir building go, the conditions found above Portage would work no unprecedented hardship. It also involves the changing of the railroad location for several miles along the river and the proposed regulation of the river will change the rate of flow of water over the Genesee Falls, which are the chief feature in one of the State's most beautiful pleasure grounds, a heritage from a distinguished citizen who is a lover of nature and of his fellowmen, and whose wishes are entitled to profound respect.

For these reasons and many others, if this reservoir is to be built, the regulation of the reservoir and the use of the power derived should certainly be retained within the control of the State.

A careful study of the ground and some fairly complete surveys made during the past few months, have caused me to believe that by perhaps changing the location of the dam and by conveying the water for power underground through a deep tunnel to a power house located at least one-half mile or more, probably two miles down stream from the lowest fall, all of this construction could be done without marring the beauty of Glen Iris in the slightest degree. Indeed by means of this storage a greater flow could be provided for the falls at those times when they will be most visited, than is now possible and very much greater than now comes to them under natural conditions in a severe midsummer drought.

By the construction of the proposed Portage reservoir and the development of this very remarkable power site, Rochester and the broad valley above it could be in a large measure, although not entirely, relieved from dangerous floods, and in addition there could be provided the equivalent of 35,000 horse power, twentyfour hours in the day, seven days per week from a new power house to be built a few miles north of Portage.

This amount of power if concentrated largely into ordinary working hours under a forty per cent. load factor, would supply about 60,000 horse power for industrial and municipal uses in the Genesee valley and its neighborhood, exclusive of the mill sites at Rochester and beyond this would add 20,000 horse power to that now furnished by the Genesee within the city limits of Rochester.

Surely when the time comes that the large expenditure involved may be prudently made, the gain to the city and to the State from this reservoir, in flood relief and in new power development, will be far greater than any possible injury.

The power rentals at ordinary prices for steam power would show a good profit, but the marketing of such large amounts of power would be slower under the conditions of to-day, and since the capital involved in the entire development for both dam and power house would be very large, it is to be kept in mind that the dam could be built and used for flood control and for reinforcing the summer flow of the river at Rochester and adding to the Rochester water powers for a term of years before building

any power plant at Portage and before building anything connected with the tunnel except its head gates and a hundred feet or so of its upper end.

Much more study is needed for obtaining proper data on many of the important considerations affecting this project, but the main features have been provisionally worked out with a very fair degree of completeness, as will be made plain in the following pages.

STREAM FLOW MEASUREMENTS ON UPPER GENESEE.

The object of first importance in studies of water power, storage and flood control is to learn the volume of flow of the river from day to day.

That portion of the Genesee drainage area lying upstream from the proposed storage dam at Portage is of much greater average altitude than the portion of the drainage area lying down stream from Portage and Mount Morris, and is enough different in character of surface and forest cover, so that it is important to base estimates of yield upon gagings near the site of the storage dam rather than to rely upon the measurements at Rochester, which moreover are understood to lack precision.

The flow of the Genesee, like that of most other rivers, varies so much from month to month that any few scattered gagings however useful for marking the extremes of flood and drought, are without value for estimating power or the requirements of flood control.

Mr. A. S. Kibbe, p. 447, N. Y. State Engineer's Report of 1890, says concerning measurements of the flow of Genesee river prior to his own gagings: "No systematic gaging of its flow has ever been made at one point continuously or for any length of time.”

Mr. Kibbe made gagings from June 17th to December 2d, 1890, see p. 716, N. Y. State Eng. Rep. 1896.

The only other continuous gagings of the upper river, of which record can be found prior to 1903, were made at Mount Morris, at the Hydraulic Power Company's dam, where the drainage area is about 1,070 square miles, from September, 1893, to February, 1907, thus covering a period of three years and four months. These were made over a dam with a very irregular crest. (See State Eng. Report 1896, p. 636; also Rafter Hydrology of N. Y., p. 333), which dam was washed away by a flood in February, 1897.

A gaging weir for accurately calibrating the measurements over the old Hydraulic Power Company's dam was built at Mount Morris, 21⁄2 miles upstream therefrom, about August, 1896. (See Rafter Hydrology, N. Y., p. 308, 333, 602.) Unfortunately, it was washed out by a flood about the middle of October, after having been in use only about 22 months.

Another gaging station on the Genesee also called the Mount Morris station was established by the U. S. Geol. Survey in 1903, and the results have been published without making it plain that this third Mount Morris station was at Jones' Bridge below the mouth of the Canaseraga creek, where the drainage area is about 340 square miles, or 33 per cent. greater than at the old station of the same name. In fact, the State Engineer's reports of 1905, p. 649, gives erroneously for the drainage area of this new station the old area of 1,070 square miles, whereas actually it is about 1,410 square miles.

A fourth gaging station near Mount Morris over the new stone dam called the "High Dam was established by the U. S. Geol. Survey in 1905.

At Rochester, the Genesee had been somewhat roughly gaged for many years. Mr. Rafter made use of these gagings from February, 1897, to November, 1898, in piecing out his table of flow for the Genesee at Mount Morris. The only records of this series that we find published in the State reports or the United States reports are those from December, 1894, to November, 1896, inclusive, given in the State Engrs. Rept. of 1896, pages 639 and 718-9.

At Elmwood avenue bridge, Rochester, in February 9, 1904, a station was established, as described in State Engineer's report of 1905, p. 650.

In 1903 and 1904, during low water, measurements were made under direction of City Engineer of Rochester at the Johnson and Seymour raceway and on the Carroll and Fitzhugh raceways.

The topographical maps of the U. S. Geol. Survey are as yet incomplete for a large part of the Genesee drainage area. For the drainage area above Rochester, the figure of 2,365 square miles, given in the city engineer's report, has been adopted.

ACCURACY OF MOUNT MORRIS GAGINGS.

Regarding the quality of these gagings, they are not of as high precision as desirable, but doubtless average within, say, five per cent. to ten per cent. of the exact figure, and from a study of description of the form of crest used in September, 1906, to calibrate the Hydraulic Power Company's dam, the actual flow is, say, probably five per cent. greater than the computed flow.

Opposite page 602 of Hydrology of N. Y. are shown photographs of the timber dam and of the measuring weir and on p. 308, Hydrology, is shown the cross section of the measuring weir.

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I find no good reason for the adoption by Mr. Rafter (see p. 718, State Engrs. Rept. 1896) of the Francis formula Q-3.33 LH for computing the flow over this standard weir, which had a queer form of crest, very different from that prescribed by Mr. Francis, giving less contraction at the underside of the jet, and which form would therefore give a somewhat larger discharge than the standard Francis weir.

The comparisons of discharge between this calibrated weir and the dam crest presented on p. 334 of the Hydrology, lack satisfactory agreement, but while more precise gagings covering a much longer term are desirable, we have here already measurements of actual flow longer and more accurate than those on which the preliminary plans of the great majority of water power installations have had to be based, and since these Rafter gagings probably slightly underestimate the flow and embrace the remarkably severe drought of 1895, they are on the safe side.

In addition to the period from September, 1893, to November, 1897, covered by the actual gagings at Mount Morris, Mr. Rafter in Hydrology of N. Y., p. 333, estimated the probable flow at the storage site from April, 1890 to November, 1892, from some actual gagings that had happened to be maintained during that period for other purposes on Oatka creek, a lower tributary, of only about one-fortieth of the area above Portage, which probably, because of