More than a quarter of a million dollars worth of damage was done and but three houses left standing in the town of Edgewick at 2 o'clock yesterday morning, when the impounded waters of the Cedar river reservoir burst through the porous north bank of the basin and roared down the Snoqualmie valley.
But for the courage and forethought of Charles Moore, night watchman at the North Bend Lumber Company's plant at Edgewick, who, in the face of the threatening waters, tied down the lever of the mill whistle and then hurried from door to door arousing the sleeping residents, scores of persons might have lost their lives. As it is a dozen families are homeless while the costly main plant of the North Bend Lumber Company is a total wreck, the planing mill badly damaged and the Innovation Shingle Company's mill was whirled down stream for a quarter of a mile.
Equally important, however, is the fact that the great spring of water boiling from the side of the bank is rapidly cutting its way back toward the reservoir which contains Seattle's water supply and likewise feeds the municipal power plant. If, under the tremendous pressure of the impounded waters, this stream, already flowing with such volume as to form a river 150 feet wide, cuts back to its source, the entire contents of the reservoir may go out.
To guard against this contingency it may be necessary to reopen the big draining hole in the masonry dam and relieve the pressure in the reservoir. City Engineer A. H. Dimock said last night that he would take this step if necessary to save the north bank, but that until he received a report from one of his men who is now at the scene of the break, he could not say it would be done.
The direct cause of the break is believed to be the test recently made by flooding the reservoir in order to determine if the sealing which the city has done on the north bank, was effective.
Under the unusual pressure, the north bank, which is no more than a huge glacial dike a mile wide, formed of loose gravel and debris from some prehistoric age, and through which water seeps readily, permitted the water to break through in an unusual volume.
The Snoqualmie valley, which lies on the south [north!] side of the glacial dike, is approximately a thousand feet lower than the reservoir. At a point 400 feet up on the side of the bank, and about half way between the new masonry dam and the old Cedar lake dam, the break occurred.
According to W. C. Weeks, president of the North Bend Lumber Company, he notified the city engineer's office of the threatening condition of the waters, and two men were sent there Sunday. At that time the waters seemed to be subsiding. A few hours later, however, the break occurred.
At approximately right angles to the point where the water was bubbling forth from the principal spring--there are several leaks through the bank--is located the village of Edgewick, which is likewise at the junction of Boxell creek and the south fork of the Snoqualmie River.
Without warning, the spring suddenly began to gush forth faster, and Boxley Creek, which is fed by the leaks from the reservoir, began to rise rapidly.
At the rate of a foot every two minutes the water rose. Moore, who was destined to play a Paul Revere part, had been keeping close watch. As the threatening flood mounted higher and higher he saw the dam, which formed the log pond for the mill, would go. Dashing inside the mill, he reached for the whistle cord and, a second later, the deep, sonorous roar of the signal drowned the muttering of the waters. Lashing the cord down tight, he hurried out of the mill and began making the rounds of the fifteen little cottages that clustered just below the mill and the dam.
"Out of your beds, the dam is going to go!" he would shout, after hammering on the doors, and the he would be gone.
Startled, the sleepy residents sprang from their beds. Most of them grabbed their clothes in their arms and fled. A few, however, paused to dress.
And then, with a splintering crash, the dam gave way.
All that saved the few who had hesitated was the main mill of the North Bend Lumber Company. For a few seconds the flood broke against it, the force of the waters checked. This gave the belated ones a fighting chance.
Through swirling, yellow waters that clutched at their feet, then their knees, they dashed for the nearest high bit of land. And before they reached it the water was at their armpits. Yet they made safety.
A quarter of a mile above, the Innovation Shingle Company's mill was being undermined. Weaker and weaker grew its supports, and finally the flood took a last fling at it, worked it loose, and the entire structure revolved slowly like a gigantic top, as it moved down the stream. At a point close to the planing mill of the North Bend Lumber Company, it lodged, and as the waters began to recede slowly it stuck fast.
From a near-by knoll the sixty odd survivors looked down on what had been the location of their homes. The only structures in sight which had not felt the test of the waters were three houses which had been built on a higher point of land. The occupants of these immediately gave what succor the could. But three houses would not shelter them all.
Someone started a fire on the knoll, for the damp chill of the air was penetrating. Soon a great bonfire blazed up, and around it huddled men, women and children, some joking, others silent as if dazed by the nearness with which death had passed. And thus they stayed until through the foggy mists of the eastward hills the sun sent a few half-hearted rays.
Soon after daylight a special Milwaukee train was sent out from North Bend to Edgewick. It brought four families to North Bend. The others preferred to remain behind.
While more than a thousand feet of Milwauke trackage above Edgewick is submerged, some of it as deep as fifteen feet, the line between North Bend and Edgewick was still open. Milwauke trains are now being routed over the Northern Pacific from Easton.
With the coming of daylight the wreckage presented many odd sights. Eleven automobiles were lost in the flood. One of these, badly battered, was jammed into what had been the kitchen of one home. Another perched on the broken roof of a garage.
The houses were owned by the North Bend Lumber Company. All that the residents of Edgwick lost was their personal belongings. But for many of them, it meant practically a clean sweep.
Edgewick is located about five miles east of North Bend. In the latter town the waters of the Snoqualmie, while risen abnormally by the flood, had not caused any damage.
While the full force of the flood has spent itself, the water cutting through its subterranean passage had given no hint of receeding at Edgewick. But little more damage remains to be done there, unless the full head of water in the Cedar river reservoir should be loosed.
Whether the new break can be effectively sealed from the reservoir side was not known last night. Apparently the great spring boiling out of the side of the hill is fed by scores of smaller veins in the heart of the hill. The task will be to effectively stop each one of these outlets by sluicing earth over the face of the north bank on the reservoir side, assuming this loose earth will sift into the outlets and eventually choke them.
The reservoir is cradled between a wall of solid rock and the glacial dike. At the mouth of this valley is located the city's masonry dam, which cost approximately $1,900,000.
The porous nature of the north bank was discovered in 1914, when the reservoir was filled. Immediately the south side of the bank became dotted with springs.
Sealing operations were ordered by the city. During the four years that followed, $135,129.27 has been spent in sealing the north bank. Recently, after an inspection, city officials announced that the sealing process had been a success
The history of the Cedar River project is an interesting one, dating from the time the city aquired a watershed of 137 square miles in 1897. Fourteen years later, at a cost of practically $2,960.00, the project was completed and the permanent masonry dam accepted by the city.
Seattle acquired and owns 37,982 acres, 59.35 square miles, in such a position as to have the flow of water from surrounding territory equivalent to 137 square miles. Following the purchase of the land much discussion as to the development of a light and power plant took place in the city council, and the matter was finally made a question for popular vote. Preliminary work and preparation occupied years of investigation and discussion. Before a vote was taken on the issuance of bonds for the cnsruction of the dam, $300,00 was spent by the city engineer's office in going over the watershed studying the geological stratum of various sites suggested for a dam.
In 1910 bonds in the sum of $1,400,000 were voted by the people for the erection of a permanent masonry dam by day labor. The bonds were for twenty years at 4 1/2 percent, a matter of $1,260,000 interest bringing the total cost, with the $300,000 spent in preliminary work and preparation, to $2,960,000. In January, 1911, the first construction work was done. By April, 1913, $700,000 had been expended and the work was far from done. At that time the failure to get results caused the city council to advertise for bids, and on July 7, 1913, the work of finishing the dam was awarded to a private contracting company. In November, 1914, the work was completed and early in the following month was formally accepted by the city.
The dam, inspected by many local and visiting engineers was pronounced a good dam thoroughly constructed and equal to any test that it would be called upon to perform at that location.
The location of the dam site was a moot one for years prior to its being built and following its construction the prophesies of many were found to be correct. While the dam was strong enough to impound all water that might be piled up behind it, it developed that the ground on the north side was of a porous formation and as the water raised it seeped through the north bank around the end of the dam.
The dam itself is 1,000 feet in length with a maximum heighth of 202 feet and a varying thickness at the base running up to 196 feet with fifteen feet thickness at the top across its entire length. At the south side of Cedar river the dam was anchored to the canon-like rock walls. The base of the dam rests on a rock ledge across the river bed and extends 300 feet beyond the edge of the north bank into gravelly, porous ground on that side and twenty feet above the soil for that length.
Following the completion of the dam it was pointed out by engineers that while the dam was on a rock foundation, that foundation was plainly but a spur of rock. From a point two miles east of the dam, on the north side, bedrock has not been touched, and in the explorations to locate its depth glacial deposits of more than 300 feet have been penetrated.
In 1915, a year after the city had accepted the dam the water turned in behind the dam from the temporary structure above the impounding basin was deflected and turned back by the dam itself and forced into and through the porous north bank. It ran through the sand and gravel as fast as it could be poured into the impounding basin, the rate of flow and seepage loss increasing tremendously with the increase of the volume of water behind the dam. An attempt was made to increase the raise in water by gradual stages, but as the water raised the seepage and outflow increased.
At about the same time the water began rising in Rattlesnake lake, some what lower than the impounding basin and across the Snoqualmie basin at the outskirts of the little town of Cedar Falls, near the Milwuakee railroad station at Moncton. Whether it was a seepage from the impounding basin that caused the rise in Rattlesnake lake has never been determined, but the rising of the water in Rattlesnake lake was coincident with the attempt to use the new basin behind the dam.
Rattlesnake lake kept rising until dozens of buildings in Cedar Falls were swept away from their foundations and carried away, many residents losing their homes. The Milwuakee railroad was compelled to cut a drainage ditch over toward the Snoqualmie river to save its tracks, which traversed the highest level of the depression. Many claims for damages were filed against the city as a result of the sudden devastation of the little town.