On May 21, an open house was held by several irrigation companies and contractors to introduce waters users, public officials and citizens to a new diversion structure that has been completed to replace the old City Dam on the Spanish Fork River.
The new City Dam Diversion Structure is located near the Canyon View Park along the River Trail at the mouth of Spanish Fork Canyon. The City Dam diverts water into the Mill Race Canal, which delivers irrigation water to Southeast Field Irrigation Company and West Field Irrigation Company and bypasses water to Lake Shore Irrigation Company. In the past, Spanish Fork City received water from the Mill Race Canal and continues to receive water credit at the City Dam site, but the city has moved its point of diversion to other locations. The City Dam is the point at which all water in the Spanish Fork River Drainage is measured at and accounted for to allow proper division of decreed water rights to all appropriators.
The new diversion structure replaces the old City Dam, which was constructed approximately 1927. The old dam had deteriorated to the point that it was very near failing, was no longer a reliable measuring device, and had to be replaced. The floods of 1983 nearly washed the old structure out because it couldn’t bypass enough water to avoid flooding the surrounding areas.
Men and dynamite were on the scene to blow up the old City Dam, but Lynn Mendenhall, the Spanish Fork water commissioner at the time, knew that if the dam was destroyed, the farmers of the river bottoms and Palmyra would not be able to get irrigation to their crops that summer. The farmers’ livelihoods would be in jeopardy, and Mendenhall convinced the others to breach the south abutment of the dam and leave the dam intact to allow for summer irrigation. The farms were saved, but the Canyon View Park and Golf Course were severely damaged.
Years later, John Mendenhall became the water commissioner and recognized the failing dam as real problem that couldn’t be ignored much longer. Water needed to be regulated and measured accurately and safely. Future floods needed to be passed by the structure without damage to surrounding land. The City Dam was falling apart. People from the various irrigation companies and Spanish Fork City began looking at options and talking to John Mendenhall about what type of structure would be needed and how a new dam could be constructed and funded.
After the high river flows of 2001, the need for a new diversion structure arose anew. The water commissioner, irrigation companies and Spanish Fork City began exploring options for a new dam. After much discussion and debate, a call for proposals was sent out to have engineering firms give some ideas for the design and cost of a new diversion structure. It was learned that a new dam would be a large project and expensive. More discussion and debate followed.
Finally, in the summer of 2013, engineer Bruce Hall was selected and his design was accepted. It utilized control gates that were relatively new in design, Obermyer Control Gates, that can be used for control and measurement of the water. The gates are operated by filling and deflating air bladders. Funding was sought for and secured from the State of Utah’s Division of Water Resources, which has a program to provide funding for water projects in Utah. The planning and permitting process began in the winter and spring of 2013–2014. Demolition and construction began in September of 2014 with completion of the new City Diversion Structure in April of 2015. Ray Mecham and Lynn Boots Crisler acted as canal company liaisons.
The open house featured a welcome by West Field Irrigation Company President Gerald Hill. Bruce Hall Engineering was thanked as well as other contractors who worked on the project: FX Excavation and Concrete, Obermyer Hydro Inc., Allen’s Welding, James Simons Electrical, Strawberry Water Users Construction Crew and others. Thanks was also given to the Utah State Division of Water Resources for the funding of the structure. John Mendenhall, Spanish Fork Water Commission, gave a history of the dam. Brent Money offered a prayer. A luncheon was provided and a tour of the facility was conducted.
State-of-the-art design and construction and controls have come together in the new structure. It should provide security of diversion and measurement of water as well as better flood control well into the future. The new City Dam Diversion Structure can be viewed from the Spanish Fork River Trail just west of the Canyon View Park.
The Spanish Fork City Dam Diversion Structure is shown as viewed from just off the Spanish Fork River Trail west of Canyon View Park.