Water: Nonpoint Source Success Stories
Colorado: The Badger Creek Watershed Project - Improving Fisheries on the Arkansas River
The Badger Creek Watershed Project -
Improving Fisheries on the Arkansas River
Badger Creek, a tributary of the Arkansas River, is an important spawning stream for brown trout. However, this approximately 135,000-acre watershed also has a history, a reputation, for dumping sediment-laden flood waters into the Arkansas River. Working together, landowners, local governments, special interest groups, and state and federal agencies have made progress to improve the conditions of the watershed and reduce nonpoint source pollution.
The project's goals are improved water quality in the Arkansas River, improved fisheries in the creek and river, and protection and improvement of the creek's historical significance as a brown trout spawning stream. To ensure the success of these larger goals, the project includes the following objectives:
- establish flood and sediment controls throughout the watershed,
- stabilize stream channels,
- improve the vegetation in riparian areas, and
- improve water and land management.
A work in progress
A section 319 grant gave ranchers the incentive to install fencing, alternative livestock watering places, and erosion control structures on state and private land. The Colorado State Board of Land Commissioners provided additional funds to help their leaseholders install best management practices on state-owned land. Project-encouraged planned grazing systems are now in place on 79,788 acres.
The U.S. Forest Service constructed 124 erosion control dams and installed 344 miles of stockwater pipeline, four stockwater tanks, and 8.6 miles of fence to facilitate grazing. The Forest Service also closed and revegetated 7.9 miles of unneeded roads. The Bureau of Land Management completed a land exchange for 80 acres of important riparian area, which included the primary source of perennial waterflow to the creek. With other partners they established a riparian grazing demonstration area to show land managers and owners how varying the number of livestock and grazing seasons can improve a riparian area.
Reduction in sedimentMonitoring results indicate general upward trends in characteristics of vegetation, soils, and stream channels in areas where management actions have changed. Increased vegetative cover and species diversity provide shade and protect soils, which exhibit increased microorganism activity, more consistent temperatures, and greater moisture. Willows are growing once more, with increasing vigor.
As controlled grazing produces more vigorous vegetation on the streambanks, the stream channel begins to narrow and deepen at the monitoring sites. The vegetation helps to catch sediment and litter and build up streambanks. Sediment transport changes are also apparent, indicating a reduction in sediment transport per volume of water.
|CONTACT: Bill McKee
Colorado Department of Public Health and Environment
Management Initiatives Along the South Platte River -
The Northern Colorado Water Conservancy District
The Northern Colorado Water Conservancy District (based in Loveland, Colorado) begins north of the Denver metropolitan area and extends more than 1.2 million acres along the South Platte River and its tributaries to the Colorado-Nebraska border. The alluvial aquifer along the South Platte has been extensively developed for irrigation, industrial and municipal purposes, and drinking water. However, high nitrate levels are presently found in wells serving several municipalities. These communities have been forced to seek alternative drinking water supplies. The available alternatives, ranging from reverse osmosis treatment plants to participation in a regional water supply pipeline, are costly to residents.
In addition to health concerns (in some areas, the nitrate level may be as high as 40 parts per million [ppm] -- four times the recommended level for drinking water), the nitrogen also potentially jeopardizes the production of high quality sugar beets and malting barley, the district's major cash crops. While corn for grain is the largest acreage crop, approximately 40,000 acres of sugar beets are also grown in the basin, with gross revenues exceeding $30 million annually.
Demonstrating total resource management
Among projects undertaken to protect the aquifer and the South Platte River, the Northern Colorado Water Conservancy District is sponsoring a demonstration of total resource management for irrigated cropland. Two small farms of 45 and 20 acres, respectively, provide area producers an opportunity to evaluate whole farm management and the transferability of similar management practices to their own operations. At the same time, they can assess the program's cost-effectiveness because the farms have real expenses and income.
Since a major environmental goal of the project is to use best management practices to reduce the amount of nitrate-nitrogen in soil and water, initial phases of the project focused on nutrient and irrigation management. Later phases will demonstrate sediment control with conservation tillage and polyacrylamide use. Polyacrylamide, also known as PAM, is a soil additive that acts as a flocculent to consolidate soil particles suspended in the irrigation water. The consolidated particles drop out of suspension and stabilize the furrow surface.
Two chapters of the Colorado Young Farmers Education Association -- the Thompson Valley Young Farmers and the Valley Young Farmers -- provided the demonstration farms. Together these Young Farmer chapters have more than 80 active members farming an estimated 20,000 irrigated acres in the project area. Each chapter served as the advisory committee for operations at its farm site.
The agribusiness community near each farm also made significant contributions; it provided inputs for crop production, including seed, agrichemicals, compost, manure, and equipment. The young farmer organizations prepared the ground prior to planting and provided seed, fertilizer, chemicals, and the water for irrigation. The District was responsible for planning and performing all other field operations necessary for normal crop production.
Irrigation practices and results
All fields were furrow irrigated. The control fields were conventionally irrigated, while water was applied to the others with surge valves and gated pipe. Surge valves pulse water across the field, cycling water back and forth between two alternating sets of furrows, using a solar powered controller. The valves allow the field alternate wetting and drying cycles during irrigation, which permits more uniform application across the field and generally improves the efficiency of water use. Efficiencies can be expressed as the ratio of water needed or used for crop production to the volume of water applied to the field. The closer the value of crop water use is to the actual application, the greater the efficiency. Conventional furrow irrigation ranges from 25 to 60 percent efficiency; surge irrigation efficiencies range from 30 to 80 percent.
Irrigations were scheduled using the root zone water balance method along with soil moisture readings. Average irrigation efficiencies for the project are depicted in Table 1.
Groundwater was analyzed for nitrate-nitrogen on the Thompson Valley Farm, using samples from four observation wells. The wells were sited so that one pair represented water entering the site, while the other pair represented water leaving the site (Table 2).
|Table 1. Irrigation efficiencies on demonstration farms along the South Platte.|
|THOMPSON VALLEY YOUNG FARMERS|
|FIELD, CROP, IRRIGATION METHOD||.||Irrigation Efficiencies|
|Sugar Beets||5.7 acres||59%||36%|
|Corn 1 - surge||6.5 acres||52%||33%|
|Corn 2 - surge||5.8 acres||48%||34%|
|Corn - conventional||18 acres||31%||N/A|
|VALLEY YOUNG FARMERS|
|Corn 1 - surge||5.8 acres||46%||21 - 36%1|
|Corn 2 - surge||4.8 acres||39%||21 - 37%1|
|Corn - conventional||10 acres||36%||N/A|
|1 Fields were conventionally irrigated during first half of season at 21% efficiency. Surge valves were used during second half of season,, increasing efficiencies to 36% and 37%.|
|Table 2. Nitrate-nitrogen in groundwater observation wells, in parts per million (ppm).|
|.||GROUNDWATER ENTERING SITE||GROUNDWATER LEAVING SITE|
In addition to the field demonstrations, the District also operated a surge valve trial program. Cooperating producers had free use of a surge valve for one irrigation season, as a way of introducing them to the unfamiliar technology. District personnel provided technical assistance in programming the valve and suggesting installation options. Where practical, irrigation application efficiencies were calculated from measures of the amount of water applied and field runoff. Of the 72 valves loaned during a three-year period, 60 percent were subsequently purchased by the producers. CONTACT: Bill McKee Colorado Department of Public Health and Environment (303) 692-3583