To prevent flooding in a desert, sometimes you must build a dam without a river.
While the U.S. Army Corps of Engineers, Walla Walla District is known for the dams it currently operates, there are many other projects it has contributed to over the years. The district partners with different agencies, from local governments to other federal organizations, to build important infrastructure and keep people safe. This is a collection of some projects resulting from those partnerships.
A dam without water
Zintel Canyon, located on the south side of the City of Kennewick, Wash., is dry for most of the year, yet prone to flood events. Between 1907 and 1984, records show an average of one flood event in the region every seven years. The largest of these was on February 5, 1907, when an estimated peak discharge of 700 to 1,000 cubic feet per second caused severe flooding in the area adjacent to the Columbia River. As the City of Kennewick grew, it needed to address the threat of flash flood events.
In 1991, the Walla Walla District and the City of Kennewick made an agreement to build a flood control project. The City of Kennewick needed a solution, and the Walla Walla District was able to help. The project was authorized by the Flood Control Act of 1965, and the district built a dam in Zintel Canyon.
Completed in 1992, Zintel Canyon Dam now stands just off Hildebrand Blvd, at the southernmost edge of the City of Kennewick.
The dam is designed to be self-regulating. The structure contains a series of orifices arranged in a vertical line. If water builds up behind the dam, these orifices allow it to drain at a safe, predetermined rate. A human operator can close gates to keep water behind the dam but, by default, the gates are left open. Water draining from the dam is routed through a series of underground conduits and aboveground channels through Canyon Lakes Golf Course, preventing flooding to homes and businesses.
The area experienced a potential flash flood event on Jan. 31, 1997, when significant levels of snowmelt ran down the canyon, building up behind the dam. The resulting pool was about three feet deep.
The City of Kennewick owns, operates and maintains Zintel Canyon Dam. The Walla Walla District performs a periodic inspection every five years to make sure the dam is ready, should it ever be needed to prevent flooding.
Over the years, the district has collaborated with local partners for missions ranging from flood risk management to ecosystem restoration. In 2015, the district partnered with the Port of Kennewick to improve aquatic and riparian habitat at Clover Island, a 16-acre island just above the confluence of the Columbia and Snake rivers that serves as a commercial area and marina. The project, completed in 2023, improved conditions for Endangered Species Act-listed salmonid species, while also benefiting birds, wildlife, and aquatic species.
The district is currently partnering with the City of Gooding, Idaho, to rehabilitate flood control structures and increase safety for the inhabitants of the city.
Working with Reclamation
The US Bureau of Reclamation operates approximately 490 dams across the United States and is certainly proficient at dam construction. Still, in the 1970s, a project developed that required flood control expertise and the agency collaborated with the Walla Walla District to build a dam.
Since 1911, at least 17 floods caused considerable damage in the Willow Creek and Sand Creek floodplains, sometimes flooding thousands of acres of land near Ririe, Idaho. USACE and USBR prepared a report in 1961, indicating the importance of constructing a dam at Ririe. Congress authorized the Ririe Project through the Flood Control Act of 1962 for flood control, irrigation and recreation.
The Walla Walla District, well versed in flood control projects, designed and built the dam on Willow Creek, a tributary of the Snake River. The project, located near the cities of Ririe and Idaho Falls, Idaho, includes the earth and rockfill dam, reservoir, and a floodway bypass outlet channel. After construction was completed, dam operations were relinquished to USBR, though USACE still oversees flood control operations during flood season.
The Walla Walla District works closely with USBR on other efforts as well, including management of a three-facility water storage system in Boise, Idaho. USBR owns and operates Anderson Ranch and Arrowrock dams, while USACE owns and operates Lucky Peak Dam. These dams are located on the Boise River, upstream of the City of Boise. USACE and USBR coordinate the operations of these three dams, making effective use of a combined 1 million acre-feet of water storage capacity.
Collaborating within USACE
It should come as no surprise that the Walla Walla District works closely with other USACE districts, especially those in the Pacific Northwest.
Walla Walla District’s 107,000 square miles of jurisdiction used to be the USACE Portland District’s responsibility. After the Walla Walla District was established on Nov. 1, 1948, the two districts worked closely to develop infrastructure on the Columbia and Snake rivers.
The construction of McNary Lock and Dam, a concrete run-of-the-river dam on the Columbia River, was a collaboration between the two districts, and completed in 1957. The Walla Walla District later completed John Day and Willow Creek dams in 1971 and 1983 respectively, which are now operated by the Portland District.
One of the Walla Walla District’s current dams, Lower Monumental, a concrete run-of-the-river dam on the lower Snake River, was built by USACE Seattle District. The Walla Walla District handed construction to the Seattle District in July 1962, and the dam was completed in 1970.
Let us try
Compiling an exhaustive list of all Walla Walla District efforts would be difficult. It would need to include the multiple levee systems maintained by the district, such as those in Lewiston, Idaho and Jackson, Wyoming.
Part of the USACE mission is to “deliver vital engineering solutions, in collaboration with our partners.” This statement acknowledges the ramifications of working together and encourages the district to continue collaborating with partners, accomplishing so much more than on its own, keeping the lights on, the grain moving, the fish swimming and the people safe.
| Date Taken: | 09.09.2024 |
| Date Posted: | 09.12.2024 11:00 |
| Story ID: | 480682 |
| Location: | WALLA WALLA, WASHINGTON, US |
| Web Views: | 16 |
| Downloads: | 0 |
This work, Sharing the load: Partnering to keep people safe, by Hannah Mitchell, identified by DVIDS, must comply with the restrictions shown on https://www.dvidshub.net/about/copyright.
