There is a lot to like about working and living in Colorado, and many people are finding out why. In the last 20 years, the state’s population has increased by slightly more than 1.5 million people. The state is among the top 10 fastest-growing in the nation, as more than 700,000 residents moved to the state between 2010 and the end of 2019.
Sustained growth, however, puts increased pressure on infrastructure. The American Society of Civil Engineers (ASCE) released its 2020 report card and assigned a D+ grade to the state’s schools. The report gave C- grades to the state’s roads and transit systems.
Similarly, the population surge has strained the state’s already-thin water resources. Colorado’s drinking water and wastewater received C- marks on the same report.
“Colorado’s infrastructure is reaching a critical crossroads,” the ASCE report said. “As the Centennial state’s population grows — thanks in part to our abundant sun and outdoor recreation — the infrastructure we depend on is suffering from years of under-investment. As a result, our schools, roads, bridges, sewer lines, water treatment facilities, and many other critical assets are failing to keep pace with the needs of our growing state.”
Brighton, about 25 miles outside of Denver, had just a little more than 21,000 residents in 2000. It is expected to surpass 41,000 residents in 2020. Brighton took a critical step last year toward guaranteeing its water supply for the long term. The city completed the construction of a $5.4 million project, the Erger’s Pond Augmentation Station, that should serve its residents for decades — and provide a model that other communities can follow.
Project at a Glance
The project required the installation of two raw water pump stations near a city-owned reservoir that is used for water storage. The reservoir is located adjacent to the South Platte River, which serves as the main water resource for the eastern side of the state. Aslan Construction built the pump stations. One pumps water from the river into the reservoir, and the other will be used to pump water back into the river.
The new station includes nine submersible pumps in underground wet wells to move water, along with a gravity line. The total storage capacity at Erger’s Pond is 1,800 acre-feet, or about 586 million gallons.
The station will capture excess river water during the spring runoff for subsequent water withdraws. Curt Bauers, the city’s utilities director when the project started, said if the water could not be captured it could have flowed out of state.
“This water will be used to meet our current – and a significant portion of future – annual customer water demands,” he said.
Teams also built new spillways to direct water flow and “riprap” slope protections to protect the pond’s banks from erosion.
“Improving the slopes and spillways are vital to keeping the pond from being washed out,” Bauers said.
The city had been using temporary pumps, but that solution proved costly and inefficient.
“Construction of permanent infrastructure to facilitate pumping operations was necessary and beneficial to the city,” said Jake Hebert, a civil engineer who worked on the project.
Need for Augmentation
The dual-purpose stations are needed to comply with the state’s augmentation requirements. In 1969, the state adopted the Water Rights Determination and Administration Act. One part of the act requires junior water users on over-appropriated streams to offset depletions to senior water rights. Priority to water rights is based upon when they were acquired, and holders of senior rights have the first claim to withdraw water. Ownership of land is insufficient to convey a right to use water.
Brighton’s primary water supply comes from alluvial groundwater wells, which have junior rights, and therefore the city must augment supply so senior water users downstream have sufficient water. “Water in the West is very different from water rights in the Eastern United States,” said Dawn Hessheimer, water resource specialist for the City of Brighton.
Water allocation is a complex process in Colorado, and has been so for centuries. Zebulon Pike, one of America’s earliest western explorers and the man for whom Pikes Peak is named, referred to Brighton in his diary as the “Great American Desert.” The Colorado Encyclopedia said before Colorado achieved statehood in 1876, “water scarcity drove the territory to adopt the Colorado doctrine,” a water allocation system whose basic premise was “first in time, first in right.”
Multi-Tiered Water Issues
Several factors contribute to the state’s water shortage. The state’s Western Slope, defined as being west of the Continental Divide, receives about 80 percent of the state’s water supply. About 80 percent of the state’s population, however, resides on the much drier eastern side of the divide.
The South Platte River scrolls through Colorado and Nebraska for nearly 380 miles. But, more than 4.5 million residents rely on it for drinking water, energy, food, irrigation, and other activities.
The lack of rain also contributes to the state’s water issues. Brighton only receives about 15 inches of rainfall each year, and Colorado is ranked among the 10 driest states in America. The average rainfall in the United States is 38 inches.
“Brighton water storage reservoirs are a vital component to our municipal water system and our ability to supply water to our citizens,” Hessheimer said. “Think of the chicken and the egg. Which came first? You cannot legally draw water from wells for treatment without the ability to augment the well pumping.”
Preventing Leaks
With those water issues, the project needed to make certain water retention remained uncompromised. Hebert said a key challenge was placing the reservoir filling pump and wet well on a narrow strip of land between the river and the reservoir.
Some of the slurry wall — a clay bentonite wall usually built around reservoirs to prevent water leakage in and out of the reservoir — had to be removed to build the wet well and pump station. “Much care was taken to rebuild the slurry wall, and it resulted in no leaks,” Hebert said.
The wet wells are accessed by 14 floor doors manufactured by The BILCO Company. The doors are manufactured from aluminum and feature type 316 hardware for corrosion resistance and many years of dependable service. They feature engineered lift assistance for easy, one hand operation, automatic hold open arms, and an industry-leading 25-year warranty. Tim Bosworth of Dalco Industries procured the doors for Aslan Construction.
“The BILCO hatches were preferred by the operations department and are used to access the wet wells,” Hebert said. “They were installed directly above all of the submersible pumps to provide a way to pull the pumps from the wet wells for maintenance and future replacement.”
Model to Follow
Brighton is not unique in Colorado in its limited water supply. Augmentation is a relatively new concept, but the model that the community created could be a template for others to follow.
“This project is certainly transferable to other communities in Colorado,” Brighton officials wrote in an awards submission to the Colorado branch of the American Public Works Association. It was selected in the association’s contest for medium-size communities as the top environmental project. “The lessons provided from the Erger’s Pond Augmentation Station Project are applicable to many Colorado communities, because building permanent pumping facilities is much more cost effective and efficient in the long run.” WW
