Excessive Pumping Created 200 Foot Fall of Region’s Vital Aquifer
By Thomas Renner
Residents of the United States are faced with a number of concerns, particularly issues with the nation’s crumbling infrastructure. One resource that is of particular distress, especially in the western U.S., is water availability. There are multiple reasons why some communities are water-starved, including drought.
Groundwater depletion also contributes to water shortage issues. The U.S. Geological Survey reports several regions have seen shrinking levels of groundwater. In New York, counties on Long Island have seen the water table lowered and saline groundwater has moved inland. Land subsidence issues extend from West Central Florida to the Southwest desert and even into the Pacific Northwest.
A recently completed project in Washington, however, aims to restore the precious resource that people, especially the region’s widespread farming community, depend upon. The first pumping station of the Odessa Groundwater Replacement Project will provide water for up to 10,500 acres. The project, called EL47.5, includes nearly nine miles of pipes. The $20.8 million project started in 2016, and was redesigned in 2017-2018 after a grant allowed for additional capacity. Construction was completed in late summer 2020 and became operational in the spring of 2021.
The project will eventually include nine systems to offset the rapid decline of the Odessa Aquifer, which has fallen more than 200 feet since 1980. For a community wrestling with water issues for more than 40 years, the project will bring much-needed relief.
“It’s nearly 200,000 people and over a dozen, maybe two dozen small communities that really represent the fiber and the structure of the Columbia Basin and agriculture and farm communities as we know them,’’ said Vicky Scharlau, Executive Director of the Columbia Basin Development League.
EL47.5, which is named for its distance from the start of the East Low Canal, includes six pumps and a pump house. It is the first of nine proposed pressurized pipeline systems being built to deliver Columbia Basin Project surface supplies to replace groundwater use on 87,000 acres across Grant, Adams, and Lincoln counties.
“Water is ordered daily, conveyed through the East Low Canal and delivered on a 24-hour basis,’’ Scharlau said. “The water is sent down the canals and the pumping station is just one of many outlets that takes water from the canal and distributes it to the different lands.”
EL47.5 is one cog in the Odessa Groundwater Replacement Program. The systems are part of the larger Columbia Basin Project, which currently serves approximately 680,000 acres.
The scope of work for the Odessa Groundwater project is far-reaching. Workers widened 46 miles of the East Low Canal, constructed seven siphons, will add seven radial gates and replace 12 bridges.
“Lands are all upslope from the East Low Canal, so pumping is a necessity,’’ Scharlau said. “Open channel flow deliveries were financially prohibitive and would require a new canal system to be built. Besides regulatory hurdles, costs were estimated in the billions. For this situation, this was the best option for water delivery to farmers.”
EL47.5 is the first pumping station in the expansive Odessa Groundwater system, and teams faced a series of challenges that hopefully will be reduced in subsequent stations. “Regulations, costs, and easement issues were overcome by time and perseverance,’’ Scharlau said. “Along with typical construction issues. Once it was designed, construction was pretty smooth. The pandemic occurred during construction of the plant, and that certainly didn’t help.”
Powerful Pumping Station
Water is pumped through the system via a 12,800 square feet pump station, which will push out up to 73 million gallons per day.
The station includes one pump of 700 horsepower, and 5 pumps of 1,250 hp. The powerful system can deliver more than 63,000 gallons per minute. The station has a delivery capacity of 10,500 acres, pumping water at 140 cubic feet per second at 345 feet total dynamic head. The pumps pull water out of the canal and are delivered based on daily orders of irrigators who bought water on long term contracts.
The intake structure includes a sump that is 35 feet to 86-feet wide, 80 feet long and 18 feet deep. It includes 820 cubic yards of concrete and 145,000 pounds of rebar. The pumps deliver water to 46,892 feet (8.88 miles) of pipelines that are 14 to 60-inch in diameter with 15 turnouts.
“This is the first pumping plant in the project and the lands that it serves is what makes this pump station unique,’’ said Jon Erickson of the East Columbia Basin Irrigation District and project manager of the Odessa Groundwater Replacement Project. “This is an important step in getting water to the farmers that need it.”
The ECBID designed the pumping station, which was built by Goodman & Mehlenbacher Enterprises, Inc.
The pumps are an important part of the project, but installing and accessing the pumps when they eventually need replacement was one of the important design considerations in the station’s construction.
Teams will access the pumps through six roof hatches manufactured by The BILCO Company. The custom hatches, 6-feet, 6-inches x 7-feet, are fabricated with polycarbonate dome covers for natural daylight and engineered lift assistance for easy, one-hand operation. They are also modified for hand winch operation, allowing them to be easily opened and closed from inside the building.
The aluminum hatches, which were supplied by Anderson Specialties, were custom-fabricated to meet unique size requirements. “They were proposed by the contractor and met the specs that we required,’’ Erickson said. “They were also important because they allowed pump and motor access by crane.”
The issues with groundwater depletion that Washington is encountering is common throughout the United States. The problems, however, go deeper than the lack of water.
Sustained groundwater pumping also leads to a multitude of other issues. Deterioration of water quality, increased pumping costs, drying up of wells, and reduction of water in streams and lakes are some of the consequences of overreliance on aquifers. So too is land subsidence, which is the gradual settling or sudden sinking of the Earth’s surface due to removal of subsurface materials.
Subsidence occurs when large amounts of groundwater have been withdrawn. The layers within an aquifer compact and settle, resulting in lowering the ground surface.
A study this year reported that 19 percent of the world’s population will be affected by land subsidence by 2040, accounting for 21 percent of the global GDP. One of the most extreme examples of land subsidence has occurred in California’s San Joaquin Valley, a large farming community. Since the 1920s, excessive pumping of groundwater at thousands of wells has caused land to sink as much as 28 feet (8.5 meters).
Eastern Virginia has also experienced land subsidence with overuse of the Potomac Aquifer. Like the Odessa project, officials have executed a plan to enhance sustainability of the region’s long-term groundwater supply.
The solution, however, is dramatically different as it uses highly treated water that would otherwise be discharged into the Elizabeth, James, or York Rivers and treats it to meet drinking water quality standards. The water is then added to the Potomac Aquifer, which is the primary source of groundwater throughout eastern Virginia.
A report in 2020 from Old Dominion University and NASA’s Jet Propulsion Laboratory found that Norfolk and Virginia Beach are subsiding at the rate of approximately 3.5 millimeters every year. The report confirmed less technical observations, but also delivered one surprise. The rate of subsidence varies by neighborhood, sometimes by as much as 15-20 percent.
As an important economic driver in the region, water from EL47.5 and the Odessa Groundwater project will be critical to the farmers, families and businesses. Maybe farmers could have continued to draw water from the aquifer. Maybe, though, the aquifer might eventually go dry. That’s not a chance the region is willing to take.
“It is only speculative what and when would have happened without the project,’’ Scharlau said. “However, trends have shown a consistently declining aquifer.”
The U.S. Bureau of Reclamation said more than 700 irrigation wells were drilled in the Odessa region. In June 2017, the Washington Department of Ecology issued cease and desist orders requiring landowners to stop pumping groundwater. In December 2017, the Department fined landowners for illegally pumping more than 500 million gallons of groundwater from the aquifer to water 530 acres of crops that included potatoes, alfalfa, and timothy hay.
Agriculture is an important component in the Washington state economy. The state is the third largest food and agricultural exporter in the United States, generating $10.6 billion in revenue across 39,500 farms and ranches. Water is a critical resource, and the Odessa Groundwater Replace Project will be instrumental in helping farmers maintain their livelihood.
While a labor intensive and sophisticated solution, the project illustrates a creative solution toward solving an infrastructure problem that faces many U.S. communities.
About the Project
What: EL47.5 is the first pumping station to become operational in the Odessa Ground Water Replacement Project in Washington.
Why: The water system is needed to support farmers and others due to an aquifer that has fallen more than 200 feet since 1980.
The project: The distribution system includes more than nine miles of pipes, six pumps, and a pump house. The project cost $20.8 million.
Extensive reach: The system will deliver water to 10,500 acres, pumping out water at the rate of 63,000 gallons per minute.
Accessing pumps: The heavy duty pumps are accessed for repair and replacement through six roof hatches manufactured by BILCO.
Did you know? Groundwater in the Odessa Subarea has been depleted to such an extent that water must be pumped from wells as deep as 2,400 feet – nearly half a mile.
Thomas Renner writes on building, construction, engineering, architecture, and other topics for trade industry publications throughout the United States.