Oklahoma watershed dams historically significant and critical to the future

There’s a chance that almost 1,400 of Oklahoma’s watershed dams will have beaten Larry Caldwell to retirement by next year.

Overall, the State has 2,107 such flood control dams protecting homes, businesses, roads, bridges, and other infrastructure, as well as crops, farmland, and ranch land. The “however” to this is that by 2020, 1,380 dams will have passed their 50-year design life. 

Larry Caldwell, Oklahoma Conservation Commission Watershed Specialist, with arms outstretched, explains the functions of a watershed flood control dam. This photo was taken a few years ago in Garfield County at one of the dams in the Upper Black Bear Creek Watershed.

The reality is they can’t retire, they just need some remediation.

Fact is, some things and some people are too needed to let go of – the dams are an example of the former as is Caldwell, an Oklahoma Conservation Commission (OCC) Watershed Specialist, of the latter.

“Think about last week’s intensive rains in Oklahoma, specifically in western areas of the state,” OCC Executive Director Trey Lam said. “There were losses of property and damage to land and any such loss is a tremendous loss. However, that’s exactly why the benefits of these dams are so important, and that’s what these watershed projects do, they protect areas from flooding losses that used to occur frequently before the dams were built.  In addition to protecting crops and farmland, some of the dams also protect lives. They also are designed to reduce damages to buildings, agricultural products, roads, bridges and so many other vital aspects of our daily lives. That’s also why the work of those such as Larry Caldwell is so critically important.”

Caldwell, an Oklahoma professional engineer, talked about the storms that covered a large area in Oklahoma and Kansas.

“A Natural Resources Conservation Service (NRCS) ‘National Watershed Benefits’ computer model estimates the daily monetary benefits resulting from watershed projects for a specific storm,” Caldwell said. “These ‘benefits’ are essentially the damages that would have occurred from that storm had the dams not been built. The report detailed $11 million in monetary benefits resulting from the watershed projects in western Oklahoma and central Kansas during the 24-hour period from 7:00 a.m. May 7 to 7:00 a.m. on May 8. Watershed projects in Upper Elk, Sugar, Boggy, Timber, Cavalry, and Sandstone Creeks in Washita, Beckham, Custer, Caddo, and Roger Mills Counties received the most rainfall and benefits during that storm.”

Recent storms

Monte Tucker ranches near Sweetwater in western Oklahoma. The Oklahoma Mesonet weather network station at Erick in Beckham County, about 15 miles south of Sweetwater, recorded 6.5 inches of rain in a short amount of time last week. Tucker was asked about the importance of flood control structures for weather events such as this.

“Being younger than a huge majority of the upstream flood control dams, all I can attest to on flooding is the stories from my 96-year-old grandmother that still lives and ranches on Buffalo Creek in southwest Roger Mills County” Tucker said. “She often tells of how a generation ago a heavy rain of 2-plus inches in a short time would cause major damage to roads, bridges, crops and pasture lands downstream.”

However, Tucker said today when they witness 4 to 6 inches in a few hours it just fills the flood control dams, in which his grandmother also comments, “They don’t hold near what they once did due to filling in with silt.”

“Then the designed structures do the job of slowly releasing the flood waters and this prevents catastrophic damage,” Tucker said. “The creek still rises, but it flows, usually within its banks for a longer period and the days of a ‘wall of water’ taking everything, including lives with it are in the past.”

Tucker added, “This past week in an epic rainfall event where we have aging upstream flood control dams, the damage was minimal, mostly water gaps in creeks and streams but south of Sayre where I’m not familiar with any dams, there was major damage to fences, crops, livestock, roads, bridges and structures.”

He said the investment needs to be made in maintaining and rehabbing these flood control dams.  

“My grandpa would always tell people, ‘We get about 20 inches of rain a year here in far western Oklahoma, and ‘ya ought to be there on that day,’” Tucker said. “Thus, controlling flood waters is a must.”

Jimmy Smith, lives in Beckham County and is chairman of the North Fork of Red River Conservation District.

Smith said for the past six months they have been extremely wet and most watershed structures are at almost full capacity and are running down the drawdown.  

“The large rain we had last week filled them even more, with some watersheds backing up over roads and bridges,” he said. “What most people do not realize is the fact that the structures do not hold as much water as they used to due to runoff sediment over the years.  When these structures were built, all cultivated land was conventional tillage which had much more soil runoff.  Today most of the cultivated land is minimum tillage or no-till which results in less soil runoff which helps but the structures still need rehab for safety conditions.”

Benefits of watershed projects

Watershed projects were based on the conservation principal of holding the raindrop high in the watershed as close to where it strikes the ground as possible. The watershed programs are one of the best examples of federal, state and local partnerships to address natural resources issues. Watershed projects are federal-assisted, not federally owned. NRCS provided funds to plan, design, and construct the dams. Project sponsors, typically local conservation districts, are responsible for operation and maintenance of the dams to assure they continue to function as there were designed.

Oklahoma has 129 watershed projects in 64 counties. These projects include 2,107 flood control dams and provide multiple benefits to citizens. Most of the 2,107 dams are located on private lands in rural areas and many people don’t even know they exist, let alone how much they affect their daily lives.  Most people don’t know they were constructed for flood control. How does that benefit agriculture producers as well as non-producers. The average benefits provided by Oklahoma’s Watershed Projects is over $96 million each year. 

“Nine out of 10 Oklahomans are living within 20 miles of a flood control dam,” Caldwell said. “Flood control dams are close to all Oklahomans. We live, work and play under their protection every day. Flood control makes modern Oklahoma life possible in many rural communities.”

Oklahoma has been a national leader in the United States Department of Agriculture (USDA) Watershed program since the 1940s when Soil Conservation Service (SCS) watershed authorizations were being deliberated. The first of the 12,000 watershed dams constructed in 47 states was built near Cordell, Oklahoma in 1948. 

The number of dams built each year peaked in 1965 when 157 dams were built.  During the decade of the 1960’s, an average of two watershed dams were constructed each week. Many of the watershed dams in Oklahoma are reaching the end of their 50-year designed lifespan. Since most of the dams were designed with a 50-year design life, during the decade of the 2010s, two dams came to the end of their evaluated life each week. So in addition to 1,380 watershed dams that have reached the end of their evaluated life this year, an additional 200 dams will reach that mark within the next five years.

“However, just because a dam exceeds its evaluated life, it does not mean that it won’t safely function as designed for many years longer if properly maintained,” Caldwell said. “However, funds are critically needed to maintain these dams so that they can function as designed and remain safe. Watershed dams are a part of an estimated $2 billion the public infrastructure that must be attended to. If funds are not provided for maintenance, not only will devastating flooding return in the areas prior to the projects being constructed, but lives will be at-risk.” 

Rehabilitation of these aging dams is a priority in Oklahoma, so that they can continue to protect people’s lives, property, and natural resources for the next 100 years. To date, 53 rehabilitation projects have been authorized to meet current safety standards; 38 of these have been completed. The remainder are in various stages of design or construction.

Caldwell continues to serve

In a way, dams and many of the engineers who design them never retire, they just keep providing benefits to people, to places, to production. Again, Caldwell is a great example.

Caldwell retired from the USDA Natural Resources Conservation Service in 2009 after serving more than 41 years.

However, he immediately took on a new title – Watershed Specialist for the OCC.  In this role he continues over  a half-century of service in which he has assisted landowners and communities with planning, design, and construction of thousands of conservation practices involving erosion control, water management, wildlife development, waste management, and flood control. Caldwell is a nationally-recognized authority on dam safety and rehabilitation of aging dams. He currently provides leadership for a team assisting local conservation districts to evaluate aging flood control dams and to develop related emergency action plans and rehabilitation designs to meet current safety standards. He is also leading a national project to design and implement a web-based system to monitor flood control dams in Oklahoma and the nation.

“I was fortunate to have had the job that so many people talk about – I got paid to do what I loved to do,” he said. “I enjoyed the people I worked with and experienced that sense of satisfaction of seeing a project completed and providing the benefits intended.”

Throughout his career he has had the opportunity to have worked with some of the conservation and watershed pioneers in Oklahoma who worked during the peak of the dam building era.  

“I heard many stories of the devastating floods that frequently ravaged many rural communities,” Caldwell said.  “I gained a great respect for Oklahoma leaders in the watershed program whose work made a difference to not only Oklahoma, but the entire nation – Dick Longmire, L.L. “Red” Males, Nolan Fuqua, and Lloyd Church to name a few. The historic flooding of many places around Oklahoma are now just stories in history books.”

Caldwell said the watershed projects have not only reduced flooding, but have also provided critical water supplies for many communities as well as recreation for thousands of Oklahomans. 

“The challenge we, as Oklahomans, have today is to assure that funds are provided to assure that the dams are maintained in safe condition so that they can continue to provide these benefits for generations to come,” he said.