Reports reaching city hall Thursday stated that the water is still pouring in undiminished quantity from springs at the point in Boxley canyon where the flood occurred Monday morning. Measurements taken by J. D. Blackwell, hydraulic engineer employed by the city on the Cedar basin sealing job, show that the flow of water is sixty cubic feet per second.
While no immediate danger of further damage by the overflowing water is anticipated, city hall officials are fearful as to what might result in case there should be heavy rains or sudden melting of snow from a Chinook in the mountains.
Nothwithstanding the fact that J. D. Ross, superintendent of the lighting department, and other officials have urged that the plug in the masonry dam be removed, in this way lowering the water in the reservoir, no steps have been taken to exercise this precautionary measure.
J. J. Youngs, superintendent of the water department, who is in charge of operations at the Cedar river project, believes that all danger is past, and says he sees no necessity for partially emptying the reservoir. He believes the water should be allowed to remain in the basin so that the earth it carries will settle and help build a foundation for the sealing process. The water is within two feet of the spillway, having been lowered but little since Monday. City officials are awaiting a report from City Engineer A. H. Dimock, who spent Thursday in an investigation of conditions at the reservoir.
A party of councilmen, consisting of William Hickman Moore, Oliver T. Erickson and W. D. Lane, will go to Cedar lake Saturday to remain over Sunday for the purpose of informing themselves as to the situation.
Severe freezing weather, heavy rainfall or sudden melting of snow might cause further disaster, in the view of several city officials. Should the water in the impounding basin rise to a much greater height there is a danger that the old wooden dam might be washed out. In that event the city would be deprived of one-third of its electric supply.
Freezing of the walls of the reservoir on the north bank, where seepage from the impounding has basin has collected, might cause the water to collect in such quantities as finally to burst the walls and break out in another disasterous flood. It is possible also that there may be other locations in the big moraine where seepage has been collecting that may burst through at any moment. Some of the city officials that have studied the situation believe that the whole moraine is underlaid with a big reservoir whose base is the mountain on which the moraine was deposited. The filling of this subterranian reservoir to the limit of its capacity with seepage from the Cedar lake impoundng basin is believed by these officials to have caused the outbreak of water at the north bank. The seepage had been collecting for weeks in this reservoir, which was finally filled to overflowing. The flow of water from this reservoir will from now on equal the amount of seepage from the impounding reservoir, they claim.
Difference of opinion exists among city officials as to whether or not the sealing operation will prove a success. Superintendent Youngs believes that when the bottom of the basin is given the primary treatment of earth sluiced from the banks and a top dressing a foot thick of clay from the deposit owned by the city 6,000 feet up the mountain side the reservoir will hold water as well as any reservoir, even those lined with concrete or asphalt base.
"Every reservoir, even those lined with asphalt or concrete, leaks to some extent," Mr. Youngs says. "This is true of all our city's reservoirs. While it cannot be known definitely until the job is completed, I believe that the Cedar lake basin will be made to hold water to an extent that will make it worth while to have undertaken the work. We are already getting 1,000 kilowatts of power from the water stored in the impounding basin. Only one-fifth of the reservoir from the masonry dam up the Cedar river basin, a thousand feet, has beeen given the primary treatment. We have more than a mile to go with the sealing operation before the old wooden dam is reached. After that we expect to give the entire basin a top dressing of clay a foot thick. It is my belief that we will then have a basin that can be used for the purpose for which it was planned."
Mr. Young's theory as to the causes leading up to the break in the north bank is that water seeping from the upper part of the impounding basin which had not been given the primary treatment soaked through the glacial moraine and collected in some underground reservoir near the north bank. There it gradually accumulated until the subteranean reservoir was filled to the bursting point, when the earth gave way and the water poured out, tearing away huge sections of the hillside. The gap in the mountain side caused by the flood is 1,000 feet long, 500 feet wide and 100 feet deep.