Page images
PDF
EPUB

engraving department, and the extension of the jurisdiction of the Lake Survey to include the New York canals will involve additional expense. To provide for these and to continue the profitable use of the equipment and floating plant in prosecuting the field work on the lakes with the usual vigor, it is estimated that $150,000 may be profitably expended during the year ending June 30, 1913, and it is recommended that this amount be appropriated and that the appropriation be formulated as follows:

For survey of northern and northwestern lakes, and of the lakes and other natural navigable waters embraced in the navigation system of the "New York canals," including all necessary expenses for preparing, correcting, extending, printing, and issuing charts and bulletins, and of investigating lake levels with a view to their regulation, to be immediately available, one hundred and fifty thousand dollars.

Dates and amounts of appropriations for surveys of Northern and Northwestern Lakes.

[blocks in formation]

Printing and issue of charts for use of navigators and electrotyping copperplates for chart

[blocks in formation]

Surveys, including investigations of lake levels, correcting, printing, and issuing charts

and bulletins.

[blocks in formation]

PRESERVATION OF NIAGARA FALLS.

During the fiscal year just ended, operations under allotments to the Lake Survey from the appropriation of the act of June 29, 1906, were confined to a continuation of water level and slope observations on the Niagara River, tests of turbines in the plant of the Niagara Falls Power Co., and the supervision of power and transmission companies operating under permits from the Secretary of War.

Slopes in the Niagara River.-Automatic gauges established in the spring of 1910 at Chippawa, International Railroad Co.'s intake, Suspension Bridge, and Whirlpool, were maintained until ice conditions in the fall made their removal necessary. During the past winter the records of these gauges for 1909 and 1910 were reduced in the office, and an elaborate study was made of all Niagara River water level data obtained since 1906. It was found that the increase of diversions by the power companies at Niagara Falls and natural and artificial changes in the regimen of the river have disturbed the slope relations to some extent since previously determined. From the records of the gauges maintained in 1908, which year represents about the average conditions since 1906, relations have been established between the water levels at these stations and Lake Erie stages at Buffalo breakwater gauge. The formulas for other gauges previously maintained were reduced to 1908 conditions by known relations of fluctuations with the permanent gauges. The seasonal cycle of slope caused by the subaqueous growth of vegetation in the Chippawa-Grass Island pool during the midsummer was eliminated so far as possible. The resulting formulas for river heights at the several gauges in terms of Lake Erie stage at Buffalo for the mean conditions between July 1 and November 1, 1908, are as follows:

[blocks in formation]

The locations of these several gauges and the periods covered by the records of each are as follows:

Austin Street gauge, on the south side of the slip of the Buffalo Smelting Works at the foot of Austin Street, Black Rock, Buffalo, N. Y., was maintained during the Niagara River discharge measurements in 1899-1901, and also during the summers of 1903 and 1907, and for a few months in the early part of 1908. Elevations depend on P. B. M. Guard Lock as 576.454 feet.

Black Creek gauge, self-registering, at Black Creek, Ontario, was maintained during the summer of 1906 only. Elevations depend on a wye level line run from Niagara Falls in 1906, and correspond to P. B. M. Niagara No. 2 as 571.827 feet.

The gauge near the northern end of Schlossers Dock, at the foot of Sugar Street, Echota, Niagara Falls, N. Y., was maintained only during June, July, and a part of August in 1908. The fractional season's record made it impossible to eliminate the effect of seasonal cycle in the above formula for this gauge. It is probable that more extended observations would have shown the coefficient and the absolute term of the formula slightly smaller. The elevations depend on P. B. M. Echota as 572.922 feet.

The self-registering gauge at Willow Island on the New York State Reservation, about 50 feet above the head of the wing dam opposite the head of Goat Island, was maintained during the latter part of the season of 1906. As the record began in August, it was not possible to fully eliminate the effect of the seasonal cycle. Elevations at this point depend on local bench marks established by a wye level line from P. B. M. Niagara No. 2.

Wing Dam gauge, located on the outside of the wing dam opposite the head of Goat Island, 170 feet from the spillway at the lower end of the dam, was maintained during the summer of 1907 and during the early part of the summer of 1908. Elevations depend on local bench marks established by wye level lines from P. B. M. Niagara No. 2.

The Chippawa self-registering gauge, located on the southeast corner of the old dock on the north side of Welland River (Chippawa Creek) near its mouth, was maintained during the summers of 1906, 1907, 1908, and 1910. Elevations depend on local bench marks set by a wye level line run in 1906 from P. B. M. Niagara No. 2.

Grass Island self-registering gauge, located on the northern end of the river face of the crib work on the northern end of Grass Island, was maintained during the summers of 1903, 1907, 1908, and 1909. The observations during 1903 were abnormal, due to the presence in the river of the Ontario Power Co. diverters, and have not been used in the deduction of the formula. The elevations here also depend on P. B. M. Niagara No. 2.

A self-registering gauge was maintained on Prospect Point, about 10 feet back from the crest of the American Falls, during parts of November and December, 1908. This short period of observations did not allow of eliminating the seasonal cycle, but owing to the small relative fluctuations at this point the effect would very likely be inappreciable. Elevations depend on local bench marks set by wye levels from P. B. M. Niagara No. 2.

In the fall of 1906 a self-registering gauge was maintained for a few weeks at Terrapin Point, on the American end of Horseshoe Falls. The gauge was fastened to the south side of the iron railing around Terrapin Rock and was in very shallow water. The relative fluctuation determined probably applies only to the single point at which the gauge was located.

The so-called Horseshoe gauge, located about 100 feet above the crest of the Horseshoe Falls on the Canadian side, was maintained during the summer of 1908. Owing to the shallow water at this point, the gauge was reestablished in 1909 at the entrance to the International Railroad Co. intake canal, it being secured to the downstream side of a square concrete post at the end of the retaining wall on the lower side of the canal. The gauge was maintained in the new position during the seasons of 1909 and 1910 and is known as the International Railroad intake gauge. Elevations depend on local bench marks established by wye levels from P. B. M. Niagara No. 2.

Suspension Bridge gauge was located on the northern face of a large flat-topped bowlder on the United States side of the Niagara River, about 415 feet above the Michigan Central cantilever bridge at Suspension Bridge, N. Y. A self-registering gauge was maintained during the summer seasons in the years 1906 to 1910, inclusive. Elevations were determined by wye levels from P. B. M. Suspension Bridge (584.377 feet) and a vertical measurement with standardized base wires.

A self-registering gauge has been maintained at the Whirlpool during the summers of 1906 to 1910, inclusive. This gauge was located on the Canadian side of the Whirlpool, on the river side of an outcropping ledge of limestone, with its top ordinarily some 3 or 4 feet above the water surface. Elevations depend on local bench marks established by means of a wye level line from the local bench marks at Suspension Bridge down the tracks of the Gorge Route on the United States side, and a careful river crossing.

Discharge formulas for 1908.-The discharge of the Niagara River may be expressed in terms of the heights on the crests of any of the several distinct weirs over which the river flows. The discharge over the initial weir-the rapids in the upper river was measured in 1908 and an equation of discharge derived in terms of Lake Erie stages at Buffalo. The equation is,

Q=3904 (Buffalo -558.37).

While this weir is not a free overfall, the elevation of the water in the lower pool is proportional to Lake Erie elevations over an extended period and need not be considered in the equation. From this equation and the relation of river gauges in 1908, the discharge equations of other weirs were derived.

The flow over the weir formed by the first cascade is expressed in either of the two formulas,

or

Q=9194 (Chippawa-554.68)

Q=9194 (Grass Island-554.03).

« PreviousContinue »