May 11, 2017 – Sometime following the Pliocene Epoch two distinct drainage/watershed areas in our region were developing – the South Yuba River and the Bear River. About 50,000 years ago, these two were creating separate and eastward trending “heading cuts” towards the area of what is now Spaulding Reservoir. Over time, the individual canyons deepened and became distinct in their own way. As these heading cuts progressed, they moved closer to their intersecting destination.
During this period, at least two and possibly three glacial events occurred. The most recent, about 10,000 years ago, resulted in very significant changes to the respective watersheds. As these massive and influential bodies of ice slid down the hill, they gouged out extensive areas of rock and less resistant material that separated the South Yuba Watershed from the Bear River Watershed. As the glacier retreated, most of the upper Bear River Watershed was captured by the South Yuba River Watershed. At that point, the Bear River retained only a small fraction of its original flow. The hydrologic term for this dynamic is called “underfit”, a more conventional term would be an “ephemeral stream”. In essence, it is flowing during periods of rain or melting snow, but for the late summer and early fall or during drought is often “dry”.
About 1850, folks showed up with gold pans. The rich auriferous deposits of the Dutch Flat, Gold Run, You Bet, Red Dog, Steep Hollow, Scotts Flat and others needed vast amounts of water for hydraulic mining. Extensive and complex systems of canals, flumes, pipelines and reservoirs were created to address the needs of that time. The Sawyer Decision of 1884 put a stop to all hydraulic mining. During the mining period, many high country reservoirs were constructed to supply not only the needs of the miners’ activities, but also a growing population and the need for agricultural water, all of which brings us to today.
The existing water infrastructure in place at that time was eventually taken over by PG&E and Nevada Irrigation District (NID). The Bear River was reborn during this period, and for the most part, exists today because of the NID & PG&E water storage and conveyance systems.
In addition to the Centennial Reservoir, the District has been actively involved in sediment and Hg (mercury) removal at Combie, sediment removal at Rollins in the Greenhorn area (removing 27,000 cubic yards in 2015), and proceeding this year with sediment removal on the Steep Hollow, Bear River areas. The project at Combie is the first of its kind in the State and the District is the leader in the development and use of this new technology.
The District’s Meadow Restoration Project at English Meadows is already in motion, with participation from some of the leading scientists in this expanding field of study. On top of all of this, the District is actively funding Watershed Management programs, forest protection, water conservation measures and water quality issues as well as wildlife protection and enhancement measures.
Six miles of the river will be replaced with six miles of reservoir, which will include 32 miles of shoreline. The increase in fish habitat and other water dependent wildlife will increase dramatically, and will also provide world class trails, fishing, recreation, and increases in populations for some of our most precious species of waterfowl, frogs, turtles, and many, many other wildlife species.
An extremely important aspect of the six mile stretch is the unparalleled fire break afforded in a canyon and a region with extreme fire danger. There will still be 2 ½ miles of open river habitat between Rollins and Centennial Reservoir. There will remain approximately 13 miles of open river habitat between Combie Reservoir and Camp Far West Reservoir.
The recreational opportunities of Centennial Reservoir will be much greater than the existing conditions with virtually unlimited access and a full pallet of recreation types; hiking, sailing, canoeing, biking, kayaking, swimming, shelling craft, boating (speeds will be limited to 5mph) and just enjoying nature. The existing campground will be replaced with a modern, safe and beautiful site adjacent to the reservoir. The importance of safe, peaceful and fulfilling recreational opportunities for people of all ages is a focal point of Centennial Reservoir. Tourism will increase dramatically as folks are drawn into the beauty, benefits, and recreation opportunities of Centennial Reservoir
The new Dog Bar Road Bridge will have bike and pedestrian lanes, and at each end of the new bridge there will be parking and observation areas. Within these areas will be zones for fire, safety and rescue vehicles and equipment. This includes helicopter rescue landing locations. Recently a new type of fire attack aircraft (Bombardier Aircraft), able to scoop water while in flight, has been assigned to our area. This new aircraft, as well as the helicopters, will provide new levels of fire protection for not only the immediate area, but also the region.
The Yuba River will actually be afforded new levels of protection. All of the water rights and California Water Law for the Centennial Reservoir are for Bear River water only. All aspects of the area of origin law are fully consistent with proposed uses of water from the Centennial Reservoir.
The acquisition of the BLM parcels will likely be handled as a legislative process (and will not require significant funds). As protection of lands in our watershed, especially those adjacent to NID facilities, it is critically important these parcels will never be developed and are likely to be preserved with a conservation easement.
The site for the Centennial Reservoir was first identified in 1926. The District bought the Parker Ranch and site in 1927. The construction technology to be used for the dam is 21st century. The dam and spillway will be pinned and keyed into solid rock and will be constructed entirely of roller compacted concrete. Special energy dissipating features are included in both the spillway and dam. The site is recognized as seismically secure. The reservoir will have a surface area of 1,254 acres, and will hold approximately 110,000 acre feet of water, producing a storage efficiency greater than any other proposed storage projects in the State.
The unique combination of Dutch Flat, Chicago Park, Rollins, Centennial and Combie, allow for electricity to be generated four times with the same drop of water. After providing for our regional electrical supply security and rate stability, the water is still available for the environment, the people and for our local food supply production. The Centennial Reservoir has the potential to serve as a storage modulator between Rollins Powerhouse and Combie Powerhouses, this could help NID capture peak power production opportunities and increase operational flexibility, all in an effort to enhance rate optimization.
A dedicated and protected bird and wildlife sanctuary of 17 acres is another benefit of the Centennial Reservoir. This large, relatively shallow area will be perfect for all species of water birds and raptors, as well as trout, turtles and frogs. There will be dedicated parking, observation and study areas for school children and bird watchers.
Our wildlife friends will flourish in, on and around Centennial, just as they do around all of the reservoirs of the District. Do not forget one of our most important, but often overlooked species, the honey bee. Happy bees, happy life. Wild colonies and farmed colonies will thrive with the increased availability of water, not only from the reservoir, but also from water being applied to farms, gardens and yards in our region. A great deal of our food supply essential for life is made possible by pollination from bees.
In the final analysis, the Centennial Reservoir will become another blue jewel on the chain of incredible reservoirs that dot the Western slope of the Great Sierra Nevada Mountains. These reservoirs have provided unparalleled beauty, recreation, peace, tranquility and water for people, the environment, wildlife and our food supply. Over the last ninety years, millions of people have benefitted by having NID/PG&E reservoirs in their backyards and accessible to folks of all ages. I know that the vast majority of people in our region understand the need for the Centennial Reservoir, and are supportive in this matter. The protection of the integrity and the availability of our water supply is our responsibility, and we take that responsibility very seriously.
Climate variation is real and must be addressed. The Centennial Reservoir provides a buffer to all of the weather scenarios we have seen and still others that are possible.
It is these very reservoirs that keep most of the streams and rivers of the western slope alive and teaming with fish and wildlife. These water courses are also supported by the hundreds of small ponds on farms and ranches that are fed by NID water. Without this water infrastructure, many of these foothill and mid-elevation streams would dry up during late summer and early fall.
A few final points: The woodlands that will be cleared within the reservoir envelope will have a greater amount of area set aside in a dedicated woodlands protection area. The health of the woodlands surrounding the reservoir will be enhanced by localized cooling and beneficial humidity. Significant amounts of Hg (mercury) will be removed from the streambed during the site cleaning process.
My remaining concern at this point is recognizing and respecting Native American Peoples’ historical presence in this area, and we are actively engaged with the only tribal community that asked to be at the table through the AB52 process.
Thank you for your interest in these matters of great importance. We are now in the fact gathering phase of the project and the District will circulate to the public a full Environmental Impact Report later in 2017. I hope this letter serves to provide greater understanding of our regional water supply for not only the environment, but also our families, farms and our food supply security. Water is life. “Stored water is life in the bank.”
John H. Drew
Division II Director