What is the Centennial Dam proposal?

Dam Watchdog FAQ (download the PDF)

The Nevada Irrigation District (NID) proposes to build a new 110,000 acre-foot reservoir with a 275 foot-tall dam on the Bear River.[i] This would inundate the last six miles of publicly accessible, free-flowing river on the Bear, completely flooding the Bear Campground, more than 25 homes and 120 parcels, 140 Native American cultural sites, and Dog Bar Bridge, the only crossing of the Bear River between Highway 49 and Highway 174.


How does a dam on the Bear River affect the Yuba River?

More than half of the water in the upper Middle and South Yuba River watersheds is diverted to the Bear River. Upon entering the Bear watershed, Yuba water moves through canals and hydropower facilities, only flowing in the Bear River for short sections. SYRCL is concerned that Centennial Dam, if built, could demand even more Yuba River water, especially when dry years leave the new reservoir low.


Would Centennial Dam induce more growth?

Rather than provide for current NID residential customers, most of whom live at an elevation higher than the dam site and won’t be served by it, the new water storage may instead facilitate more residential sprawl, including as many as 20,000 homes that’ll be constructed in Lincoln within NID’s service area.[ii]


What would Centennial Dam cost?

NID has yet to release complete funding details for the dam, but their initial cost estimates have ranged from $160[iii] million in 2014 to $200-300 million[iv] as noted on the NID website. Recently, an NID director was quoted as saying “the project is likely to cost close to $500 million, which includes the new bridge as well as a possible new hydroelectric unit at Rollins Reservoir.[v]

Going from $160 to $500 million is a big increase in only two years.  And if NID borrows money for the dam, the interest payments alone could add several hundred million dollars more over time.


How would the dam be paid for?

Again, NID has yet to release a comprehensive financial plan for this proposal. NID has gone back and forth on whether future hydropower revenue will pay for the project. NID has said that a private investor, likely a major real estate developer, might be interested too. This financially risky project could leave NID’s customers severely burdened with debt.


What are the alternatives to building the dam?

NID should be looking for alternative ways to manage limited water resources that are environmentally sustainable such as restoring meadows, wetlands, and floodplains.  NID should consider a range of alternative actions such as repairing or modifying its aging facilities, improving canal efficiency, incentivizing water conservation, stopping leaks, and metering water. A new dam should be the last alternative considered, not the first.


What would happen to public access on the Bear River?

Many area residents now enjoy free access to the Bear for fly fishing, rafting, gold panning, swimming and hiking.  Centennial will inundate the Bear River Campground, resulting in a loss of 250 acres of public land that currently provides public hiking trails, river access, and camping. The Bear River is an affordable recreational site in the greater Colfax area, an economically disadvantaged community, to go on hot summer days.


What would happen to public land on the Bear River?   

NID is seeking to buy up all the federal property managed by BLM in the Centennial project area. By doing this, they seek to bypass the hydropower licensing process, potentially unraveling the benefits of minimum instream flows below Rollins Dam that the Foothills Water Network (FWN) has negotiated with NID over the past seven years.


What would happen to Native American sites on the Bear River?

The proposed dam site would completely inundate 140 Native American sites[vi], including 20 village sites and 3-4 burial sites. The Bear River serves as a territorial divide for three different Nisenan Tribal entities who still use this cultural landscape for spiritual and ceremonial purposes.


Would the dam threaten endangered and sensitive species?

NID has indicated that several species could be endangered by Centennial Dam. These include two federally listed species (the valley elderberry longhorn beetle and California red-legged frog), four state species of special concern (the foothill yellow-legged frog, western pond turtle, coast horned lizard, and tri-colored blackbird), and four sensitive plant species (Brandegee’s clarkia, inundated bog-clubmoss, Stebbin’s phacelia, and Nisenan manzanita).


If built, would Centennial fill up?

There is no guarantee that Centennial Reservoir, if built, will ever actually fully fill. The amount of surplus water needed to fill Centennial has only happened twice since 2002[vii].  Predictions about future rainfall are very uncertain. Inserting another dam on the Bear River, especially one unlikely to spill, could jeopardize water supply reliability for downstream farmers that depend on Camp Far West Reservoir—that’s a case of robbing Peter to pay Paul with serious potential consequences.


Who is challenging the project?

The Foothills Water Network (FWN), a broad coalition of more than a dozen local, state and national conservation groups, including SYRCL, is challenging this project. FWN is on top of the formal regulatory process, commenting on what NID should study in its environmental review. FWN also filed a protest of the water rights application as did more than a dozen other agencies including the California Department of Fish and Wildlife, US Bureau of Reclamation, and South Sutter Water District.

The Centennial Dam proposal has alarmed community members throughout the Bear and Yuba watersheds. Nearly 400 people attended two public meetings about the proposal in early March 2016 to express their concerns about the project’s potential impacts on the environment.


How can I get involved?

Public scrutiny of this proposal is vital, so please become a “Dam Watchdog” today. SYRCL will keep you informed of the project and how best to make your voice heard. There will be public hearings on the dam’s environmental impacts this winter and summer, where we will need the community to attend, write letters and speak out. There will be many volunteer opportunities for grassroots activists, and funds are needed for outreach and legal defense.

[i] Nevada Irrigation District. NOP: Environmental Impact for the Centennial Reservoir Project. 16 Feb 2016. https://d2xcq4qphg1ge9.cloudfront.net/assets/9324/3169978/original_Environmental_Impact_Report_for_the_Centennial_Reservoir_Project.pdf

[ii] “NID Regional Water Supply Project.” Nevada Irrigation District » NID Regional Water Supply Project. Nevada Irrigation District, Web. 20 Dec. 2016. <http://nidwater.com/nid-regional-water-supply-project/>.

[iii] Scherzinger, Rem. “NID Begins Planning for a New Reservoir.” Nevada Irrigation District » NID Begins Planning for a New Reservoir. Nevada Irrigation District, 22 Aug. 2014. Web. 05 Jan. 2017. <http://nidwater.com/2014/08/nid-begins-planning-for-a-new-reservoir/>.

[iv] “FAQ.” Centennial Reservoir. Nevada Irrigation District, Web. 09 Jan. 2017. <http://www.centennialreservoir.org/faq/#>.

[v] Weiser, Matt. “New California Dam Proposed to Combat Climate Change Concerns.” Water Deeply. Water Deeply, 06 Jan. 2017. Web. 09 Jan. 2017. <https://www.newsdeeply.com/water/articles/2017/01/09/new-california-dam-proposed-to-combat-climate-change-concerns>.

[vi] “Centennial Reservoir Project.” Board Meeting. Grass Valley. 14 Dec. 2016. Speech.

[vii] Wollan, Otis. “Case Study: Camp Far West Reservoir Spill as an Indicator of Water Supply Availability in the Bear River System for Centennial Reservoir.” Bear River Awakening Project (2016): Web. <http://www.savebearriver.com/uploads/4/7/3/8/47384675/otiswollan-parkerdam_campfarwestspills.pdf>.