Water: Nonpoint Source Success Stories
North Dakota: Section 319 Success Stories, Vol. III
LaMoure County Soil Conservation District
211 South Main
LaMoure, ND 58458-0278
|Primary Sources of Pollution:|
|agriculture (grazing and croplands)|
|Primary NPS Pollutants:|
|nutrients (nitrogen and phosphorus)|
|fecal coliform bacteria|
|agricultural BMPs (waste management facilities, grazing practices, conservation plans, low/no-till equipment)|
|agricultural practices implemented on more than 34,000 acres|
|positive trends in total ammonia and nitrogen concentrations|
Lake LaMoure, constructed in 1973, is a 500-acre reservoir on Cottonwood Creek in southeastern North Dakota. The reservoir's watershed encompasses some 107,000 acres, and agricultural production (crops and livestock) is the primary land use in the watershed. Swimming, boating, and fishing are the main recreational uses of the reservoir. Local residents, however, were becoming increasingly concerned about the deteriorating recreational opportunities at the lake. Of particular concern were the frequent algae blooms in mid- to late summer and a fish community dominated by rough fish such as carp and bullheads.
The LaMoure County Soil Conservation District (SCD) initiated an assessment of the Lake LaMoure watershed in 1995 to evaluate the relationship between land management and degrading water quality. Assessment activities included measuring water quality and quantity in the creek and lake and taking an inventory of current land use practices in the watershed. The SCD was able to determine that the recreational use impairments in Lake LaMoure were primarily associated with nonpoint source pollutants from agricultural lands, including nutrients (nitrogen and phosphorus) and suspended solids. Potential pollutant sources included excessively tilled croplands, overgrazed rangeland, and livestock winter feeding areas. Resuspended sediments and nutrients resulting from an excessive carp population were a possible factor contributing to the declining recreational use of the reservoir.
Improving agricultural land management practices in the watershed
As a result of the assessment, the SCD identified targeted conservation planning assistance along with voluntary implementation of best management practices (BMPs). This approach was initiated in 1996 with the development of a watershed project implementation plan (PIP) that identified beneficial use improvement and pollutant reduction goals, specific activities for accomplishing the goals, and a process for evaluating progress. EPA granted the Cottonwood Creek Watershed PIP section 319 funding approval in January 1997 ($301,071), and the project was initiated in March 1997. Subsequent section 319 funding ($617,249) was also awarded to the project in 1999 to support expanded efforts.
The primary goal of the Cottonwood Creek watershed project is to improve the fishery and recreational use of Lake LaMoure by improving agricultural land management practices in the watershed. Land use improvement objectives include installing 12 livestock waste management facilities and implementing conservation plans on more than 50 percent of the acreage in the watershed. Target concentrations by the end of the project include a mean annual phosphorus concentration of 0.20 mg/L at the inlet and fecal coliform bacteria concentrations that remain below 200 colonies/100 mL.
Early success beyond expectations
During the first 3 years, the project focused on the promotion and installation of BMPs that reduce nutrient inputs and maintain crop residue cover on croplands after spring seeding. Particular emphasis was placed on the promotion of annual soil testing and the use of no-till or minimum tillage equipment. Through these efforts, the project has exceeded the SCD's original expectations and is already well on the way to achieving its land management goals.
As of October 2000, conservation plans were being implemented on about one-fourth of the agricultural lands in the watershed. The main practice scheduled under these conservation plans is conservation tillage, which calls for maintaining more than 30 percent crop residue cover on croplands after spring seeding. Nutrient and pesticide management practices are also being implemented concurrently on many of the conservation acres to reduce chemical inputs. The factors with the most influence on the widespread adoption of conservation tillage, nutrient management, and other BMPs are a high level of producer participation, an expanded educational effort, and targeted one-on-one planning assistance delivered by skilled project staff. Total conservation tillage acres and other BMPs applied in the watershed, to date, are as follows:
|Conservation tillage||16,948.6 acres|
|Nutrient management||9,413.6 acres|
|Integrated crop management||2,717.0 acres|
|Crop residue use||2,246.2 acres|
|Cross fencing/planned grazing||220.0 acres|
|Hayland planting||874.9 acres|
|Tree planting (Not included in acreage total)||960.0 linear ft|
|Pesticide Management||2,454.2 acres|
|Total Acres Affected||34,874.5 acres|
Although the SCD continues to strive toward improved management on more than 50 percent of the cropland acres, they have also recently begun to direct more assistance and attention toward livestock management to reduce water quality concerns (fecal coliform concentrations) associated with livestock manure. To date, the efforts have resulted in the installation of two livestock manure management facilities and the preliminary development of several grazing plans. In addition, project staff are working with six other producers interested in installing manure management facilities in 2001. When these systems are installed, the project will be more than halfway to its goal of installing 12 manure management facilities after just 2 years of active implementation.
Continued monitoring of water quality benefits
Project progress and BMP benefits are being evaluated through water quality monitoring at three sites on the creek. Data collected at these sites include stream stage and discharge, and pollutant concentrations. The water quality variables being monitored are nutrients (nitrogen and phosphorus), total suspended solids, and fecal coliform bacteria. Baseline data collected from 1995 to 1998 and water quality monitoring have been used to define baseline conditions and reflect water quality conditions before project implementation. Water quality data collected after 1999 will be used to document the cumulative benefits of BMPs applied in the watershed because 1999 was the first year with a significant number of BMPs.
Although the project has realized quick progress toward its land management goals, the nature of the applied practices and size of the watershed make it very difficult to accurately measure the water quality benefits associated with the practices over the short term. However, a preliminary review of water quality data collected since 1997 does indicate that water quality conditions are beginning to improve at some sampling sites in the watershed.
The most notable water quality trend has been detected at the monitoring site for the headwaters watershed. Although fluctuations in the concentrations are still within the range of natural variability, it appears that the project is having a positive effect on total ammonia and nitrogen concentrations in the upper portion of the watershed. However, examination of other water quality variables, such as fecal coliform bacteria, shows mixed results. Consequently, an accurate evaluation of the Cottonwood Creek project after just 2 years of "targeted implementation" cannot be based on measured water quality trends.
A more accurate indicator during this early stage of the project is an evaluation of the number of BMPs applied in the watershed. Based on this information, the Cottonwood Creek project is achieving land management improvements in the watershed and can truly be recognized as a "success in the works." Over the long term, as BMPs mature and additional practices are installed, the water quality benefits of these land use changes will be tracked through ongoing monitoring efforts and the data will be used to confirm and quantify the anticipated success of the Cottonwood Creek project.
Riparian Project Manager
|Primary Sources of Pollution:|
|Primary NPS Pollutants:|
|bioengineering practices (slope stabilization, installation of riprap, revegetation)|
|establishment of riparian vegetation that withstands flooding|
Over the past 50 years, most riparian areas in eastern North Dakota watersheds have been mismanaged and degraded by activities like overgrazing, intensive agriculture, and indiscriminate logging. It is estimated that more than 50 percent of the original forest cover in many watersheds in eastern North Dakota has been cleared for agricultural use. In addition, unmanaged grazing has damaged a significant portion of the remaining riparian forests. Overgrazing, in combination with the 1987 to 1990 drought, left many riparian areas in a weakened condition and susceptible to insects and diseases.
The lack of woody vegetation along the river left the streambank vulnerable to severe erosion.
Initiated in 1994, the Red River Basin Riparian Project seeks to restore degraded riparian corridors in the Red River Basin in North Dakota. An advisory committee with representatives from several state and federal agencies advises the project on behalf of the project's sponsor, the Red River Resource Conservation and Development Council (RC&D). Healthy riparian corridors offer benefits for water quality, as well as flood damage reduction and wildlife habitat.
The project sponsors plan to establish up to nine demonstration sites in the Red River Basin, restoring at least 100 river miles during the 5-year project term. At one demonstration site, the Turtle River site, the lack of woody vegetation had left the streambank vulnerable to severe erosion. The situation was compounded by groundwater seeps above the baseflow elevation of the river. Between 1978 and 1995, the river migrated approximately 3.5 feet per year to the east until it was only 80 feet from the county road. When the bioengineering project was initiated 1995, the site had a vertical bank about 14 feet high.
Willows were planted along the restoration site to provide long-term stability.
Successful bioengineering practices
To stabilize the bank and stop further migration toward the road, several bioengineering techniques were implemented. The first step was to create a stable slope for the vegetation. The 14-foot vertical bank was reshaped to a 3:1 slope, using the waste from the top as fill at the toe. Riprap was then installed along the toe to the bankfull elevation. Bioengineering practices were installed as part of a workshop featuring the Natural Resources Conservation Services' bioengineering team from Michigan. Willow fascines and a brush mattress were installed along the 300-foot length to armor the bank and to begin the revegetation process.
Passing the test
Serendipitously, the Turtle River project coincided with the biggest flood of the century in the Red River valley, so it has sparked a new appreciation of river systems. It has also been well positioned to offer solutions that recognize the characteristics of a naturally stable river system.
After the bioengineering work was complete, the streambank was able to withstand spring floods and an unusual 17-inch rainstorm in July 2000.
Although some maintenance was required each spring in 1996 and 1997, the project bioengineering has survived both spring floods and a 17-inch rainstorm in July 2000. The lessons learned from experience at the Turtle River site include the following:
- Soil/plant material contact is best provided by using water to place the soil over brush mattresses and fascines. Sponsors used a power washer to wash in the soil placed by the backhoe.
- The loose fill used at the toe can be susceptible to erosion, especially in the first season. The site appears to have responded well to the repair work, but adding roughness to the toe would have helped. The use of root wads will be demonstrated at the Sheyenne River site.
- Deer and beaver find willow sprouts irresistible. At the Turtle River site, time will tell whether animals were detrimental to the survival of the willows. In the future the use of repellants might be necessary.
Riparian areas are crucial to the long-term protection and enhancement of the streams, rivers, and lakes in eastern North Dakota. Well-managed riparian zones help provide optimum food and habitat for stream communities, while at the same time serve as buffer strips for controlling nonpoint source pollution. Used as a component of an integrated management system (including nutrient management and erosion control), riparian buffers can greatly benefit the quality of the state's surface water resources.
At a workshop, the Natural Resources Conservation Service demonstrated the implementation of several bioengineering techniques.