Army Corps of Engineer begins Tule River Spillway Enlargement Project at Success Lake near Porterville
PORTERVILLE – On the heels of a historic drought, at the beginning of the implementation of historic groundwater legislation, and in light of potential flooding, Porterville will have more water in the future and a larger dam to prevent it from damaging the city below.
On Sept. 29, the U.S. Army Corps of Engineers Sacramento District, along with local and federal partners, have broken ground on the Tule River Spillway Enlargement Project at Success Lake near Porterville, Calif. The project is a cooperative effort between USACE, the Central Valley Flood Protection Board, the California Department of Water Resources, and the Lower Tule River Irrigation District to raise the gross pool elevation of Success Lake, reducing the downstream risk of flooding while also increasing the water supply capability of the reservoir.
Tulare County Supervisor Dennis Townsend, who represents District 5 including the city of Porterville, said the project will provide critical storage capacity behind the R.L. Schafer Dam as local water districts begin to implement the Sustainable Groundwater Management Act (SGMA), a 2014 law forcing water users in overdrafted watersheds, such as the Tule River, to recharge the aquifer with at least as much as they take out.
“The nearly 25% higher capacity will help prevent flooding in those years when inflow is unusually high and allow us to use that water to extend irrigation and groundwater recharge flows,” Townsend said. “We are approaching a time during the implementation of SGMA when every drop of water that falls in our water shed will need to be stored and used to offset losses in the groundwater supplies we have relied upon for years. After all the hard work by so many for the past 15 years, there could not be a better time for this project to be realized and utilized.”
Phase one of the two-phase project includes realigning Avenue 146 on the southwest side of the lake. The road currently passes through the spillway and becomes inundated during high-water encroachment. The realignment will reduce road closures due to flooding in the future and will also provide improved access for phase two project work, which includes widening the 200-foot-wide spillway to 360 feet wide and constructing a 10-foot-high concrete Ogee Weir across the spillway.
“It’s been a long time coming,” said Sacramento District Commander Colonel James Handura. “It’s taken many years of effort, not only from our dedicated Corps of Engineers employees but also from our local partners and elected officials to get this project moving forward.”
Flooding downstream from Lake Success has damaged agricultural areas west of Porterville for decades. In 1983 flooding is estimated to have caused $11 million in damages in terms of today’s money. While the current spillway can handle 10,000 cubic feet per second (cfs) from the dam through the City of Porterville, it bottlenecks to a capacity of 3,200 cfs just west of the city.
Congressman Kevin McCarthy (CA-23) – who represents the Tulare County communities of Porterville, Strathmore, Springville, Lemon Cove and Three Rivers – applauded the groundbreaking of the enlargement project over 15 years in the making.
“Once completed, the raised spillway at Schafer Dam will increase flood protection for Porterville and a vast stretch of prime farmland below the reservoir,” McCarthey said. “Gone will be the days of having to sandbag the current spillway to prevent flooding following storm events. Over the past decade, frequent drought has taught Californians the importance of water storage, and the raised spillway will increase storage at Success Reservoir by an estimated 28,000 acre-feet, providing our community access to more water.”
In addition to the increased flood protection, the communities downstream of Success Lake depend heavily on water stored in the reservoir to help support a vibrant agricultural ecosystem, and local leaders believe increased storage capacity will be a boon for the city of Porterville, Tulare County, and beyond.
“Water is such a valuable commodity, it is the most important resource that keeps the Central Valley going,” said David De Groot, the Tule River Association’s Assistant Water Master. “This valley is the breadbasket – we provide so much food to the entire world out of this valley, and the number one thing that we need to make that happen is water.”
In addition to enlarging the spillway, the project will also provide armoring for the Highway 190 bridge that passes over the lake’s Tule River South Fork, and add additional rock slope protection for Frazier Dike, located on the northwest side of the lake.
Phase One construction is expected to be complete in summer 2021, with Phase Two completion expected in 2023.
“The key here is that we’re now moving dirt,” said Handura. “This project is moving and it’s a great opportunity to work with our partners at all levels to help lower flood risk for the people of Porterville and the region.”
The project was originally authorized as part of the Water Resources Development Act of 1999. Construction on the project actually began in 2003 but was put on hold after discovering potential safety concerns with the dam.
In October 2016, McCarthy hosted senior USACE officials at Schafer Dam to discuss the project and tour the dam. Following that visit, USACE allocated $200,000 in fiscal year 2017 to the project, the first direct funding the project had received in more than 10 years.
In February 2018, Congress passed, and the president signed into law, the Bipartisan Budget Act, which included $15 billion for flood and storm damage projects. Following this law’s passage, USACE fully funded the Schafer Dam project. According to USACE officials, SREP Phase II awards are expected in fiscal year 2021.
The Lake Success dam is an earthen dam standing 145 feet tall and 3,490 feet long and is located on the Tule River about six miles east of Porterville. The dam and reservoir were authorized as part of the Tule River Project under the Flood Control Act of 1944 and construction was completed in 1961. The reservoir provides flood risk management, water storage and recreation benefits to the local area. On August 8, 2019 legislation sponsored by Rep. McCarthy to rename Success Dam as the Richard L. Schafer Dam was signed into law by President Trump.
“On behalf of the Tule River interests, we are most grateful to the Army Corps for starting construction on the enlargement of the spillway at Schafer Dam and particularly the support of Congressman McCarthy to secure funding for this critically important project,” said Schafer, watermaster for the Tule River Association.