In 2007, Parker Water and Sanitation District, a Front Range water supplier, and Colorado State University joined forces to develop a new approach to meeting Colorado’s water challenges.
Growing municipal and industrial water demand has led to the “drying-up” of irrigated farms in Colorado. Farms – and their water rights – are being purchased by municipalities and water rights are transferred from agricultural to municipal purposes. More “buy-and-dry” of irrigated agricultural land is projected in the future as the demand for municipal water resources increases across Colorado’s Front Range.
Parker Water Sanitation District, or PWSD, is exploring ways of meeting its water needs while benefiting irrigators and rural communities, thereby preserving both rural and urban economies. PWSD and Colorado State researchers initially embarked on a one million dollar study of water saving cropping practices with reduced irrigation based on a farm near Iliff. Subsequently, PWSD has secured two grants from the Colorado Water Conservation Board for $627,500 to supplement the research project.
“Parker Water was very forward thinking in establishing this project,” said Tom Holtzer, head of the Department of Bioagricultural Sciences and Pest Management and team coordinator of the study. “It has led others in the state to see alternatives to drying up irrigated farmland.”
Now three years into the study, important results are being found.
“A simple but important result from the research is that there are better ways to save water than fallowing irrigated land,” said Neil Hansen, associate professor in the Department of Soil and Crop Sciences and one of the CSU scientists leading the project.
Hansen said that water lost to evaporation from bare farmland was almost as high as water usage from a non-irrigated winter wheat crop.
“As a minimum, when irrigation is terminated, the land should be used to produce a crop without irrigation,” Hansen said.
The study evaluated a variety of crop rotations that alternate irrigated and non-irrigated crops as a means of saving water. This “rotational cropping” approach is efficient because the non-irrigated crop scavenges water and nutrients left by the previous irrigated crop. The approach reduces water use by as much as 40 percent.
Limited irrigation cropping is another water savings approach being evaluated in the PWSD study. For limited irrigation, all crops in a rotation are irrigated with reduced amounts of water.
The project has shown how to monitor soil moisture and crop growth stage to get the most return out of the limited amounts of applied irrigation. Crops under limited irrigation yield less than fully irrigated crops, but the yields are much better than for non-irrigated crops.
So far the study has shown limited irrigation as a successful approach for traditional crops like corn and sugar beets as well as for potential alternative crops, like soybeans and canola.
Part of the study is to project how saving water and moving it to cities will affect regional economies in rural areas of the state. The approach used to save the water at the farm scale can have a large influence on the economic impacts.
The PWSD-CSU study will conclude later this year. With the additional support from the Colorado Water Conservation Board, the project is addressing means to put the new ideas into practice. Researchers are evaluating methods the state can use to verify water savings at the farm level, and how water savings from individual farms can be aggregated at larger scales.
“We are heading toward a train wreck and we need to look at the tough question and find some answers,” said Frank Jaeger, district manager of PWSD. “This project addresses one important part of answers we are looking for. Providing urban water supplies, while also preserving agriculture instead of ‘buying and drying’ agricultural lands, will help avoid that train wreck.”