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In the foregoing computation the Sacandaga yield is taken strictly proportional to the Hudson yield measured at Mechanicville it is probable that the Sacandaga drainage yields 15 per cent. more than this.

INCREASE OF HUDSON RIVER POWER FROM SACANDAGA STORAGE, FIRST STAGE. Increased Power at Present Hudson Plants if Sacandaga be Used Solely for Benefit of Hudson River.

Twenty-four hour, 7 day horse power with 75 per cent. efficiency of turbine. Computation of Increased Power at the Several Sites.

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Or the Sacandaga storage as thus used in First Stage can be made to add 67,000 horsepower of 24 hour, 7-day power throughout the dryest six months of the average year at the sites already developed on the Hudson.

Granting that the Sacandaga yields 15 per cent. more runoff per square mile, the increased power will be correspondingly larger than is here computed. There is said to be a total undeveloped fall of about 70 feet between Spier's falls and the feeder dam at Glens Falls. The additional power upon this. would be substantially the same as figured above for Sandy Hill and Baker's Falls, and would therefore add 70/380 or 18.4 per cent. to the totals figured above, making the total average addition in the dryest month about 146,500 horse power, and in the dryest six months about 79,500 horse power.

POWER FROM SACANDAGA STORAGE, SECOND STAGE.

Increased power on present Hudson river plants if constant draft of 1,700 c. f. s. be drawn from Sacandaga reservoir for new power plant near Hadley. Computation of Power from the Stored Water, Per Foot of Fall.

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* Average six months, 56.81. † Average seven months, 49.91.

POWER FROM SACANDAGA STORAGE, SECOND STAGE.

Increased power on present Hudson river plants if constant draft of 1,700 c. f. s. be drawn from Sacandaga reservoir for new power plant near Hadley. Computation of Increased power at the Several Sites.

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Or the storage as thus used in second stage, can be made to add an average of 18,970 net 24 hour, 7 day horse power for dryest seven months and 21,590 for dryest six months at the several sites already developed.

At the undeveloped fall of about seventy feet below Spier's falls the additional power would be about the same, month by month as is reckoned above for Sandy Hill.

SCOPE OF THE SACANDAGA SURVEYS.

This has already been outlined on page 35 and the series of 25 maps there presented in small scale photographic reduction from the original sheets tell the story of scope and completeness of the survey so fully that little description needs to be added.

The whole area to be covered somewhat exceeds 60 square miles of which it is proposed to flood 42 by the reservoir.

A large part of the bottom of the proposed reservoir consists of flat meadow and wooded swamp lands, but the shores are mostly rather steep irregular slopes which in many cases are covered with brush making progress of survey slow and difficult.

Obviously the work of first importance was the obtaining of data for locating the elevation of the flow line, the position of the future shore line in relation to existing structures and therefore a strip varying from % to 14 mile in width aggregating nearly 16 square miles in area, was first surveyed for almost the entire circumference of the basin. Traverses were run and sufficient levels taken to obtain in a general way the lay and general elevation of the bottom land to the extent of about 25 square miles more. In addition about 2 square miles of area down stream from the dam was surveyed in connection with the power-house studies.

Beside this a rough survey was nearly completed around the Hadley Reservoir on the Hudson which will serve as a basis for future extension and which serves to locate the Hadley dam and to show the property in Luzerne and Hadley that would be affected. About 197 miles of traverses were run on the Sacandaga surveys and about 24 miles on the Hadley surveys. One hundred and fifty-five miles of check levels were very carefully run for establishing benches and 214 permanent bench marks established. During the course of the survey the elevations and positions of about 60,000 points were determined for use in mapping.

Twenty-six test borings, aggregating 1,304 feet in depth, were put down by the force under Mr. Ropes and 122 samples of the substrata preserved in glass bottles for future reference. Severe winter weather and snow caused a suspension of field work on December 10, after which the efforts of the force were concentrated on map making, designing and estimating.

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PROPOSED PLAN OF SACANDAGA WORKS.

The main features are:

1. A dam at Conklingville raising the water about 55 feet above its present level.

2. A lake of about forty square miles at high water formed by the flooding of the valley, due to this dam.

3. A spillway over solid rock off to one side of the dam and sufficient for carrying the greatest conceivable flood.

4. Sluiceways through which as high as 6,000 cubic feet per second may be discharged, these sluices and their intake forming the head works of a future power tunnel in the ledge.

The above comprise the first instalment, sufficient for giving the Hudson at Mechanicville a uniform flow during the dry six months of the year, never less than 6,500 cubic feet per second.

5. At some later date, a power tunnel under the mountain toward the power house near Hadley, about two miles in length and about twenty feet in diameter.

6. A power house equipped with four or five units for regular use, each of 10,000 kilowatts capacity and one spare unit of same size, the whole being designed to supply about 60,000 electrical horse power to consumers during ordinary working hours, every working day in the year, as per com putation on page 147.

7. A tail race about a mile and a quarter in length and formed mainly by deepening the present channel of the Sacandaga river from its mouth upwards, by means of dredging. Borings show that beneath the river bed the material for about fifty feet or more in depth is sand, shingled over with a layer of boulders and cobble stones.

Borings and test pits and studies of land values are not yet complete enough to show precisely the economic limits, but what I have aimed at is the maximum utilization that this site will afford, and subject to revision, it is now proposed that the flow line in extreme floods should seldom or never rise above contour 773 above sea level, this being with a depth of three feet over a spillway with crest at elevation 770. It is proposed that the lake should never be drawn more than thirty feet below the spillway level. It is possible that the further studies may lower the height of flow line five feet, and perhaps more.

In the early years before the power house is built, while the reservoir is used solely for the benefit of the power sites along the Hudson, all the way from Palmers Falls to Troy, the equivalent of a yearly average discharge of 1,700 feet per second (or more probably 1,900 c. f. s.) every hour in the year which such a reservoir is found capable of supplying, would be nearly all discharged within the six dry months, thus averaging about 3,100 cubic feet per second for these months, but in the dryest week of a dry year, averaging as high as 5,000 cubic feet per second, and varying month by month as needed to supplement the flow of the main Hudson, as shown in table on page 152.

In the later years after the power house is built, it is proposed to draw the reservoir at substantially a uniform rate throughout the year, regulating the rate of draft from hour to hour mainly for the benefit of this Sacandaga

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