Basin Inflow is an implementation of a deep neural network for forecasting reservoir inflow in the American River Basin located in the Sacramento, California region. The proposal model is composed of stacked LSTM layers, with regularization applied to both (L2, dropout, and recurrent dropout), followed by a densely connected layer. Model application and evaluation uses river basin data with temporal coverage from 2008-2022. Across the basin and along forks of the river, daily precipitation, temperature, snow water content and depth, and river discharge and stage are employed to predict local reservoir inflow. Data was pre-processed with a 30-day exponential moving average to give recent weather events more weight in the forecast, normalized, and made stationary for training. 14 years of data were separated into three sets: training set (2008-2017), validation set (2018–2020), and test set (2020-2022). The model achieves a lower MAE score (0.036) in inflow prediction than the baseline model.
The land currently occupied by the Folsom Reservoir is part of the unceded territory and traditional home of the Nisenan people. In spite of centuries of genocide and occupation, the sovereign Nisenan people persist as caretakers of the American River Basin.
The basin’s Nisenan Tribal entities include the Nevada City Rancheria, the Colfax-Todds Valley Consolidated Tribe, and the United Auburn Indian Community. The Nevada City Rancheria and the Colfax Rancheria were once both federally recognized, but Congress passed the California Rancheria Termination Act (1958) and later an amendment (1964) which ceased their federal recognition. Most rancherias have been restored, but Nevada City and Colfax are still trying to restore their federal status.
Figure 1
Yo’ Dok’im Pakan (Gerjuoy North Fork Preserve), 2022
Note. From left: Colfax-Todds Valley Consolidated Tribe chairman Clyde Prout III and Placer Land Trust executive director Jeff Darlington at Yo’ Dok’im Pakan. Placer Land Trust transferred ownership of the preserve to the tribe in 2022. From “California Ancestral Homelands Returned to Colfax-Todds Valley Consolidated Tribe,” by K. Ferguson, 2022, https://landtrustalliance.org/blog/california-ancestral-homelands-returned-to-colfax-todds-valley-consolidated-tribe. Copyright 2024 by Land Trust Alliance.
The Department of Interior’s Bureau of Reclamation (BOR) employs river basin observations including streamflow, snowpack, temperature, and precipitation in addition to projected water demand to operate reservoirs in California’s Central Valley Project. Water managers must optimize storage during dry periods while allocating space for flood control. In 2019, BOR approved a water control manual for the Folsom Reservoir north of Sacramento that relies on weather forecasts to make more accurate release decisions and engage the auxiliary spillway for flood management (BOR, 2021).
Sacramento and surrounding municipalities exist on a floodplain. The area receives most of its water from precipitation in the Sierra Nevada during a short wet period consisting of five to six Pacific storms on average, with high year-to-year variability (Ingram & Malamud-Roam, 2015). A difference of one to two major storms can ensure a normal versus a dry water year. Water management in the state has proven challenging since its founding. This challenge was evident in the early years of the state, when in late 1861 and the beginning of 1862 unprecedented snowfall followed by a series of warm storms drenched the western Sierra Nevada with four times its annual average rainfall, swelling the American River Basin, eliminating Gold Rush mining settlements (see Figure 2), displacing communities, and submerging Sacramento under ten feet of water (Ingram & Malamud-Roam, 2015). Notably, on January 11, 1862 the Nevada City Democrat reported Indigenous residents left the area a week before the floods, recognizing the weather pattern of atmospheric river storms.
Figure 2
Gold Rush Mining Camps on the American River, 1849
Note. Many of the mining camps above Beal's Bar on the North Fork are beneath the Folsom Reservoir. Adapted from "The Early Years", by Sacramento Public Library Authority, Images of America: Lower American River, (pp. 11-38), 2021, Arcadia Publishing.
The extensive destruction of the 1861-1862 floods in Sacramento and across the state (see Figure 3), led the city to pursue a project of raising the district by ten to fifteen feet shortly after the flooding. During the decade that followed, the American River’s confluence with the Sacramento River was located upstream. The Natoma Water and Mining Company carried out the construction of a dual-purpose dam about a mile and a half above Folsom on the American to generate hydroelectric power and capture logs drifting downstream from the Sierra (Sacramento Public Library Authority, 2021, pp. 11-38). In 1868, California agreed to grant the company with the labor of imprisoned people in exchange for acreage for what would become the state’s second-oldest prison. By 1893 Folsom Dam was finished, and in 1895 the newly built Folsom Powerhouse allowed Sacramento to emerge as one of the leading cities in the country using commercial hydroelectric power.
Figure 3
Sacramento, December 1861
Note. From "The Untamed River", by Sacramento Public Library Authority, Images of America: Lower American River, (pp. 109-127), 2021, Arcadia Publishing.
Before the discovery of gold (1848) by American and Indigenous workers in the American River and the relocation of the state capital to Sacramento (1854), approximately 15 Nisenan towns existed in contemporary Sacramento boundaries (Akins & Bauer Jr., 2021). To guard against seasonal flooding Nisenan founded towns on knolls or constructed dirt mounds. On the river banks shaded by oak and black walnut trees, roots and seeds were harvested, and waterfowl and mussels were consumed from the river (Roseville Historical Society, n.d.). Aquatic resources were well managed to secure runs of anadromous fish, including King salmon in the spring and fall, allowing fresh fish to be eaten or stored for trade. The American provided an ideal habitat for salmon (see Figure 4), with coarse gravel for burying eggs and clean, cold water for hatching (Isenberg, 2006).
Figure 4
Watershed Spawning Range
Note. Snapshot of the American River Watershed. Current salmon spawning range (23 miles) is highlighted in orange and the historical range (125 miles) is shown in the stripe overlay. From “Salmon Rivers,” by State of Salmon in California, n.d., https://casalmon.org/salmon-rivers/#american-river. Copyright 2024 by The Nature Conservancy.
In 1839, John Sutter established the New Helvetia colony in the Mexican Alta California province near the confluence of the American and the Sacramento (Akins & Bauer Jr., 2021). Sutter invited Nisenan people to work for him, exchanging food, clothing, and Hawaiian sugar. In January 1848, gold was found 50 miles upstream of Sutter’s Fort, and the siege that followed endangered both the Nisenan people and the basin. Between 1850 and 1873 California and the federal government legalized and funded the disenfranchisement, enslavement, ethnic cleansing, and genocide of Indigenous people throughout the violent colonization of the Gold Rush era, declining the state population of Indigenous people from 150,000 to 30,000 people (Akins & Bauer Jr., 2021). Nisenan were unsettled with some returning to the area after the start of the Gold Rush, relying on wage labor and traditional subsistence. In 2019, California Governor Gavin Newsom issued an apology on behalf of the state for its historical mistreatment, violence, and neglect, and established the Truth and Healing Council to provide Indigenous people a platform to correct the historical record and begin the collaborative healing process.
Figure 5
For All the Gold in the World
Note. Brianna French. (2022). For All the Gold in the World. [Watercolor and gold leaf on clay board]. Uba Seo Gallery. Nevada City, California. Exhibited at Visibility Through Art (October 8 2022–April 15 2023).
Ecological destruction coincided with the prospector invasion. Mining practices would corrode river quality, with silt clogging streams and halting annual salmon runs (Akins & Bauer Jr., 2021). Debris coated the riverbed decimating spawning grounds for millions of salmon (Isenberg, 2006). Pervasive efforts to transform the river through the shoring of levees, dredging, the separation of the river from sloughs, and years of damming, resulted in the decrease of sediment-induced turbidity that sheltered salmon from predators along with the aquatic bugs, phytoplankton, and zooplankton supporting them (Arax, 2020). By the 1870s, the California Commissioners of Fisheries reported salmon were absent from the American and debris from hydraulic mining had vanished half of the state’s salmon habitat (Isenberg, 2006). Moreover, by that time silt from the mines upstream made the water from the river unhealthy to drink. Hydraulic mines (see Figure 6) utilized great quantities of mercury as an amalgam in their sluices and much of it entered the river. Prior to the 1880s, the state’s legal environment gave protection to industry’s right to dispose of waste in public waterways while sanctioning easy and inexpensive access to natural resources. The technology that enabled miners to carve into the Sierra foothills destroyed its timber. The mines required wood for artificial channels and gates to regularize the flow of water, thereby ensuring the stability of gold production. Mountain reservoirs which delivered water to the mines also submerged entire forests. Of course, flooding was not restricted to the reservoirs. By clearing dense tree roots anchoring the natural levees of the river, the industry indeliberately released currents from their channels during spring floods. Lastly, the industrial control of water that emerged in the American River Basin expanded across western states going into the twentieth century.
Figure 6
Hydraulic Mining
Note. Mining on the American River. Adapted from "The Early Years", by Sacramento Public Library Authority, Images of America: Lower American River, (pp. 11-38), 2021, Arcadia Publishing.
Folsom Reservoir (1956) was constructed by the U.S. Army Corps of Engineers for the purpose of flood damage reduction with a timely completion. The winter of 1955-1956 brought Pacific and Arctic storms which displaced over fifty thousand Californians and flooded hundreds of thousands of acres of farmland; the Folsom Dam was credited with preventing the inundation of Sacramento (Arax, 2020). Another area within California State Parks’ American River District, the Auburn State Recreation Area, was also evaluated as a potential location for a dam that would have regulated downstream flow into the Folsom Reservoir. However, construction of the dam was frequently impeded for decades by concerns around the dam’s design, cost, and purpose. The fight over the proposed dam was acutely chronicled in Auburn State Recreation Area park ranger Jordan Fisher Smith’s (2006) memoir. In 1991, the district’s superintendent advocated for the concept of a “dry dam” which would have flooded the American River canyons after a storm. The following year the U.S. Army Corps of Engineers as well as a flood control agency formed by local governments supported a flood-control Auburn dam. Yet the quickly growing populations of nearby towns in the Fourth Congressional District exerted an opposing pressure on the district’s representative John Doolittle, and by 1995 he committed to sinking any proposal which did not generate power and store water for his district’s population. Finally, in 2008 the fights concluded when the State Water Resources Control Board revoked BOR’s federal water rights, ending the stalled project. Today decisions balancing flood events in the American River Basin, power generation, and local and state water demand must be handled by the Folsom Reservoir and Dam (see Figure 7).
Figure 7
Folsom Dam, 2023
Note. Picture of Folsom Dam as viewed from Beal’s Point in August 2023.
BOR operation in the American River Basin must withstand not only the region’s typical variability, but also shifts in timing and quantity of precipitation in a warming climate. The state’s water year now experiences earlier snowmelt with lower streamflows in the summer when demand is high (East & Grant, 2023). Positioning the reservoir to hold capacity for floods in the wet season while storing requisite supply for summer months will necessitate close observation of upstream flow variation (Naz et al., 2018) and strategic changes in operation policies downstream.
Over the past 80 years there has been a greater magnitude of wet extremes during the winter season (Zamora-Reyes et al., 2021). Atmospheric river storms are projected to be more extreme under climate change with a significant decrease in snow at higher elevations in the Sierra Nevada (Huang et al., 2020), generating sizable runoff and obstacles for flood management. In 2023, the Public Policy Institute of California released a nonpartisan report through its Water Policy Center regarding what should be the state’s water priorities (Mount et al., 2023). Recommendations for wet-year management were highlighted, and the institute identified five key areas for progress to be made:
- Proactive planning at the regional level before the onset of a wet year stipulates the integration of water supply and flood management.
- Flooding often occurs disproportionately in low-income and rural communities. Federal, state, and local agencies must consider equity in all aspects of wet-year planning. Additionally, recharge programs can be implemented to improve community drinking water quality.
- An infrastructure investment program should be created to adapt to climate change, with an emphasis on aquifer restoration, flood defenses, and nature-based solutions.
- Expanded floodways and seasonal wetlands can be leveraged to contend with ecosystem issues, flood events, and water supply concerns.
- Agencies, particularly the State Water Board, the California Department of Water Resources, and the California Department of Fish and Wildlife (CDFW) should produce a wet-year permit management plan that directs actions in high-flow events.
Preparation for annual variability of both wetter and drier years should be thoughtfully implemented from the perspective of building long-term basin health and emphasizing the resilience of the Nisenan ancestral homeland. For instance, in 2023 the northern adjacent Plumas County completed the initial phase of a North American beaver restoration project (see Figure 8) conducted by the leadership of tribal partners at the Maidu Summit Consortium and the California Department of Fish and Wildlife (CDFW, 2023). Beaver restoration is a key component in the state’s budget to mitigate the impacts of climate change, wildfires, and drought. Beavers store water on the landscape, effectively increasing groundwater recharge, summer baseflows and their duration, and fuel moisture in wildfire season along with establishing green belts which can buffer wildfires.
Figure 8
Beaver Conservation Release, 2023
Note. The California Department of Fish and Wildlife released a family of seven beavers into Plumas County, in the valley Tásmam Koyóm. CDFW database. Copyright 2024 by the State of California.
In summary, the state frequently issues executive orders to manage hydroclimate variability, but more substantial planning, practices, regulations, policies, and infrastructure are required to meet current and future water challenges.
Akins, D. B., & Bauer Jr., W. J. (2021). We are the land: A history of Native California. University of California Press.
Arax, M. (2020). The dreamt land: Chasing water and dust across California. Vintage Books.
Bureau of Reclamation. (n.d.). Folsom Dam joint federal project. https://www.usbr.gov/mp/mpr-news/docs/factsheets/folsom-dam.pdf
Bureau of Reclamation. (2021). Water reliability in the West - 2021 SECURE Water Act report. https://www.usbr.gov/climate/secure/docs/2021secure/2021SECUREReport.pdf
California Department of Fish and Wildlife. (2023, December 13). CDFW releases beavers into the wild for first time in nearly 75 years. https://wildlife.ca.gov/News/Archive/cdfw-releases-beavers-into-the-wild-for-first-time-in-nearly-75-years
East, A. E., & Grant, G. E. (2023). A watershed moment for western U.S. dams. Water Resources Research, 59(10). https://doi.org/10.1029/2023WR035646
Huang, X., Stevenson, S., & Hall, A. D. (2020). Future warming and intensification of precipitation extremes: A “double whammy” leading to increasing flood risk in California. Geophysical Research Letters, 47(16), 1-9. https://doi.org/10.1029/2020GL088679
Ingram, B. L., & Malamud-Roam, F. (2015). The West without water: What past floods, droughts, and other climatic clues tell us about tomorrow. University of California Press.
Isenberg, A. C. (2006). Mining California: An ecological history. Hill and Wang.
Mount, J., Grenier, L., Hanak, E., Peterson, C., Bardeen, S., Cole, S., Gartrell, G., Gray, B., Morales, Z. J., & Sencan, G. (2023). Priorities for California’s water: Stewarding the wet years. Public Policy Institute of California. https://www.ppic.org/publication/priorities-for-californias-water
Naz, B. S., Kao, S., Ashfaq, M., Gao, H., Rastogi, D., & Gangrade, S. (2018). Effects of climate change on streamflow extremes and implications for reservoir inflow in the United States. Journal of Hydrology, 566, 359-370. https://doi.org/10.1016/j.jhydrol.2017.11.027
Roseville Historical Society. (n.d.). Inhabitants before 1820. https://www.rosevillehistorical.org/before-1820
Sacramento Public Library Authority. (2021). The early years. Images of America: Lower American River (pp. 11-38). Arcadia Publishing.
Sacramento Public Library Authority. (2021). The untamed river. Images of America: Lower American River (pp. 109-127). Arcadia Publishing.
Smith, J. F. (2006). Nature noir: A park ranger’s patrol in the Sierra. Mariner Books.
State of California. (2024). Beaver conservation release [Photograph]. CDFW database.
State of California. (2019, June 18). Governor Newsom issues apology to Native Americans for state’s historical wrongdoings, establishes Truth and Healing Council. https://www.gov.ca.gov/2019/06/18/governor-newsom-issues-apology-to-native-americans-for-states-historical-wrongdoings-establishes-truth-and-healing-council
Zamora-Reyes, D., Black, B., & Trouet, V. (2021). Enhanced winter, spring, and summer hydroclimate variability across California from 1940 to 2019. International Journal of Climatology, 42(9). https://doi.org/10.1002/joc.7513
California Data Exchange Center: California Department of Water Resources
- Window: Daily and hourly records from 01-01-2008 to 12-31-2022
- Source: California Data Exchange Center. (n.d.). CDEC Webservice JSON and CSV. https://cdec.water.ca.gov/dynamicapp/wsSensorData
Google. (n.d.). [River Basin Stations]. Retrieved February 9, 2024, from https://maps.app.goo.gl/5ACnKE3bT1TMQ15J8
$cd <replace with desired location of project folder>
$git clone https://github.com/lauren-alexandra/basin-inflow-lstm.git
$cd basin-inflow-lstm
$conda create -n myenv
$conda activate myenv
$conda install pip
$pip install -r requirements.txt
$pip install --user ipykernel
$python -m ipykernel install --user --name=myenv
(in git bash or other conda environment)
$jupyter notebook