Debris-Restraining Barriers of the Yuba River

In the years following the discovery of gold in California, the processes of mining for this precious metal caused the removal of vast quantities of detritus from the western slopes of the Sierra Mountains into the streams and rivers of the valleys below. Gold was found in the beginning in gravel beds, where it had probably been deposited by rivers flowing in prehistoric times. These gravel beds exist in great numbers in a comparatively small area along the western slopes of the Sierra Mountains near the headwaters of streams draining into the Sacramento and San Joaquin valleys.

In securing gold from these mountains the sorting action of water was necessary, and in order to facilitate mining operations. ditches of great length and size were built, frequently at great expense, to carry water to the localities where gold had been discovered. Streams of water under great pressures were directed at these gravel banks through nozzles sometimes as large as nine inches in diameter, to break down the gravel banks and wash the detritus through sluice ways where the gold could be caught. Streams carry ing as much as 3,500 miner’s inches were not uncommon. It is thus easily seen that such powerful agencies would rapidly wash down whole hillsides, which would naturally be carried into the canyons and small streams in the vicinity of the mines, to be washed farther and farther down stream with each succeeding rainy season.

These mining operations were carried on for a number of years without interruption until the valley country below became more thickly populated, when the injuries caused to the rivers and the neighboring farm lands became important enough to cause those damaged to seek legal redress.