The Passaic Flood of 1903 | Page 5

flood of 1903 it is probable that data referred to can not be safely applied.
The flood of 1902 was the result of abundant rains following upon and melting a heavy snow. Weather Bureau records show that neither the depth of the snow nor the amount of subsequent rainfall was uniform, or even approximately so, over the Passaic drainage area. Indeed, so marked was the variation that it was believed that the mean rainfall for all the observation stations on the basin did not bear sufficient relation to observed run-off to allow of any reliable deductions. In the case of the October storm, however, the distribution of rainfall was more nearly uniform, and the run-off from the highland tributaries into the Central Basin must have been proportionately different in amount from that indicated in the upland tributary tables in the report of the previous flood. The data given for the 1902 flood can not, therefore, in the case of the highland tributaries, be applied to the conditions which obtained in the flood of 1903.
FLOOD AT MACOPIN DAM.
Mr. Morris R. Sherrerd, engineer of the Newark city water board, has furnished flow computations over Macopin intake dam, which is the head of the Newark pipe line. As about 73 per cent of the Pequanac drainage area lies above this intake, the table on page 16 shows roughly an equivalent percentage of the flow contributed by Pequanac River to the Central Basin of the Passaic. In consulting this table it should be borne in mind that the entire run-off of the drainage area above Macopin is about 25,000,000 gallons per day more than the amounts presented in this table. All reservoirs and ponds connected with the conservancy system of the Newark water supply were filled except that at Oakridge, which was about 1.5 feet below the crest of the spillway.
Flow of Pequanac River over Macopin dam, October 7-24, 1903.
[From Newark water department.]
Cubic feet. Oct. 8, 6 a. m. to 12 m. 240,600 12m. to 4 p. m. 347,600 4 to 6 p. m. 842,200
8-9, 6 p. m. to 6 a. m. 40,110,000
9, 6 a. m. to 12 m. 51,870,000 12m. to 1 p. m. 15,100,000 1 to 5 p. m. 62,430,000 5 to 10 p. m. 89,040,000 10 to 11 p. m. 19,520,000
9-10, 10 p. m. to 8 a. m. 201,350,000
10, 8 a. m. to 12 m. 75,670,000 12 m. to 6 p. m. 103,650,000 6 to 12 p. m. 73,530,000
11, 12 to 6 a. m. 56,820,000 6 a. m. to 12m. 41,440,000 12 m. to 6 p. m. 32,755,000 6 to 12 p. m. 25,665,000
12, 12 to 6 a. m. 23,800,000 6 a. m. to 12m. 20,725,000 12 m. to 6 p. m. 18,450,000 6 to 12 p. m. 15,105,000 13, 12 to 6 a. m. 13,370,000 6 a. m. to 12 m. 11,890,000 12 m. to 6 p. m. 11,230,000 6 to 12 p. m. 11,230,000
14, 12 to 6 a. m. 9,626,000 6 a. m. to 12 m. 8,690,000 12 m. to 6 p. m. 8,022,000 6 to 12 p. m. 7,353,000
15, 12 to 6 a. m. 6,952,000 6 a. m. to 6 p. m. 12,700,000 15-16, 6 p. m. to 6 a. m. 10,965,000
16, 6 a. m. to 6 p. m. 10,025,000 16-17, 6 p. m. to 6 a. m. 9,091,000
17, 6 a. m. to 6 p. m. 8,690,000 17-18, 6 p. m. to 6 a. m. 9,893,000
18, 6 a. m. to 6 p. m. 10,565,000 18-19, 6 p. m. to 6 a. m. 8,690,000
19, 6 a. m. to 6 p. m. 6,952,000 19-20, 6 p. m. to 6 a. m. 6,150,000
20, 6 a. m. to 6 p. m. 5,882,000 20-21, 6 p. m. to 6 a. m. 5,749,000
21, 6 a. m. to 6 p. m. 5,481,000 21-22, 6 p. m. to 6 a. m. 5,214,000
22, 6 a. m. to 6 p. m. 4,144,000 22-23, 6 p. m. to 6 a. m. 3,677,000
23, 6 a. m. to 6 p. m. 3,877,000 23-24, 6 p. m. to 6 a. m. 5,749,000
24, 6 a. m. to 6 p. m. 5,615,000
FLOOD AT BEATTIE'S DAM, LITTLE FALLS.
The flow over Beattie's dam at Little Falls, has been calculated according to coefficients used for the same dam in Water-Supply Paper No. 88. Recorded gage heights show that over the main dam there was a maximum depth of 11.12 feet, which continued from 2 to 8 p. m., on October 10, representing a maximum flow of 31,675 cubic feet per second. (See Pl. I, A.) In the following table is set forth the flow of the river over Beattie's dam during the flood, and for purposes of comparison, the figures for the flood period of March, 1902. It should be borne in mind in consulting this table, that in the case of the flood of 1903 exact dates