The California Gold Rush of 1849 lured many immigrants with dreams of finding wealth to Nevada County. Camps sprang up along Deer Creek where the bed was rich with gold. Communities grew rapidly with brush houses and log cabins replacing the tents. A group of Scottish immigrants, bound by a common language, settled in a flat valley about 6 miles upstream from Nevada City. The area is now known as Scotts Flat.
By the time they arrived, prospecting for gold had evolved from sifting through the creek bed by hand to the earliest form of placer mining, using a pan to help separate the gold from the sediment. Word spread of a sluice box being developed in nearby Buckeye Hill. It used the same principle as panning, but was a box with barriers along the bottom to trap the gold as water and gravel washed over them. By 1855, a local entrepreuner named Amos Laird was employing 200 pick-and-shovel miners in the area to work his network of sluices with water provided by a network of canals.
Technology would soon take a huge leap that would change life forever in Scotts Flat. Hydraulic mining, using jets of high-pressure water to wash away gravel and bolders, was developed in Nevada City in 1853. Creeks were damed to collect water and ditches built to deliver the large quantities of water needed to excavate the hillsides. Providing water for hydraulic mining became a very profitable business resulting in countless lawsuits over water rights. In 1854, the small ditches were consolidated into powerful water companies, one being the Rock Creek, Deer Creek, and South Yuba Canal Company (later shortened to South Yuba Canal Co. in 1870) controlling the canals and ditches in the Scotts Flat area.
Amos Laird, having become the largest hydraulic miner of the area, and wanting to save money purchasing water from the water companies, began building a dam in Scotch Flat (note different spelling) in 1856. This would mark the end of the Scottish mining camp. In February 1857, as the dam was rapidly filling as the result of heavy rains, it suddenly gave way sending water cascading down Deer Creek and into Nevada City where it wiped out all the bridges and several businesses.
The people of area watched in dismay as engineering resources and power replaced the solitary miner. Hydraulic mining required a company approach, employing men to wash away the hillside with high-powered nozzles. One worker with a hose could do the work of 20 shovelers. The single miner was obsolete. The mining propulation along the creek dwindled leaving a small lake behind the collapse of Laird's Dam.
Tilton, Mulloy, Cunningham, and Snell made a hydraulic mining clam in the Scotts Flat in 1865 and powerful monitors supplied by the local water systems began blasting away the hillsides in the search for gold. The gravel was washed through sluices where workers would extract the gold that settled behind the baffles. Any gold that remained in the washed gravel was picked out by Chinese workers, and the final gold spearated out by the use of mercury.
Hydraulic mining operations continued to multiply and dominate gold mining. Companies formed at Sailor Flat, just south of Scotts Flat, and at nearby Quaker Hill. The water stripped enormous amounts of dirt and gravel from the hillsides, depositing it into the streams and creeks, and carrying it downstream where it raised the level of the Central Valley and formed huge bars in San Francisco Bay. The farmland became useless and wildlife destroyed. Opposition rose and hydraulic mining was outlawed in 1884.
Fortunately for the water companies that had built their businesses providing water for hydraulic mining, the Pelton Wheel was being developed in Nevada City and would soon revolutionize power generation. Generators provided the power to move mining underground and power companies would become a new business force. The first project for PG&E was the Deer Creek Powerhouse just upstream from Scotts Flat.
Water companies were also expanding to provide more irrigation water to the farms of the Central Valley. The 1920s brought a campaign to form a water district in Nevada County. Many of the old canals and reservoirs had fallen into disrepair or were unused. Recognizing the value of a constant water supply, the Nevada Irrigation District was formed by a popular vote. NID began working on a plan to capture, store, and deliver water to the people of Nevada County.
NID built the first dam at Scotts Flat in 1928. It's now known as Lower Scotts Flat Diversion Dam and provides water to the D-S Canal. A second dam was build a bit upstream in 1948 and enlarged to its current size in 1964.
Today, the mining camp of Scotts Flat is under water, trees are growing up to cover the hydraulic mining scars, and Scotts Flat Lake is a recreation area...but the water still provides for irrigation and power generation needs downstream. Snow Mountain Ditch runs along the north side of the lake and, although no longer in use, is still clearly visible. Cascade Canal on the south side of the lake is currently being changed to a concrete pipe to continue delivering water into the future.