Improving watershed health, wildlife habitat, and ranch profitability: education and demonstration of low-cost, low-tech riparian restoration tools

Progress report for LNC21-445

Project Type: Research and Education
Funds awarded in 2021: $246,721.00
Projected End Date: 11/30/2025
Grant Recipient: South Dakota State University
Region: North Central
State: South Dakota
Project Coordinator:
Dr. Krista Ehlert
South Dakota State University
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Project Information

Summary:

Riparian systems are essential to maintaining key ecosystem services such as water regulation, biodiversity, wildlife habitat, and forage for grazing livestock. In some instances, removal of natural hydrological features (beaver dams) and heavy livestock utilization has caused degradation, stream bank erosion, channel incisions, and head-cutting. The result is soil erosion, poor water quality, loss of wildlife habitat, and reduced grassland economic potential. Recent research has been conducted on the use of low-cost, low-tech tools (LCLTT) that mimic beaver dams as a method for restoring riparian health. LCLTT such as beaver dam analogs (BDAs) have successfully been implemented in the Western U.S. to restore ecosystem services within degraded small and ephemeral streams and wet meadows. These earthen, natural material structures slow and disperse water, dissipate energy, and restore natural floodplains, improving soil water retention and increasing riparian vegetation. Despite benefits, LCLTT have not been adopted in North Central Region (NCR) grasslands due to lack of knowledge, producer apprehension and skepticism surrounding beavers, and a lack of trained technical experts and producer peer mentors. Thus, without research, extension, and educational programs to teach producers about the benefits of LCLTT and their role in riparian and rangeland health, riparian systems within the NCR will likely continue to see a decline in both environmental quality and profitability.

For this project our objectives are to 1) research the impact of LCLTT on soil moisture, riparian vegetation, and biomass production and 2) develop on-site demonstrations, trainings, and workshops for producers and technical experts on the implementation of LCLTT to improve hydrological function. We will specifically research the impact and efficacy of LCLTT on forage production, plant community composition, and soil moisture at a research field station and on producer ranches. We will test, demonstrate, and monitor practices in local settings with producers, allowing them to implement their grazing plans in conjunction with our work. Our inter-disciplinary team (range ecology and management and riparian health ecology) will work with producer participants to host field tours and workshops throughout the project to highlight successes and any limitations that arise. This will allow for flowing conversations to occur between producers and technical experts about potential adoption of LCLTT and will therefore create a holistic understanding of implementing LCLTT in the NCR. Overall, our long-term goal is to improve watershed health at landscape scales in grassland ecosystems and educate producers about the benefits of LCLTT.

Project Objectives:

Research:

  • Research LCLTT’s impact on forage production, plant community composition, and soil moisture.

Extension:

  • Implement LCLTT on cooperating ranches and at a research field station.
  • Teach technical experts and producers about LCLTT through trainings and workshops.

Learning Outcomes:

  • Learn how to deploy LCLTT on public and private lands.
  • Educate producers on riparian health.

Action Outcomes:

  • Technical experts construct LCLTT on public lands; assist producers on private lands.
  • Producers more widely accept LCLTT and implement LCTT on their operations.

System Outcomes:

  • Improved riparian health means less soil erosion, improved wildlife habitat and ranch profitability.
Introduction:

This progress report includes activities from November 1, 2021 to December 31, 2022. Below we provide an overview of activities that occurred during Year 1 of our grant. We have had great success so far, and are excited to see where this project is at the end of the grant's life.

Cooperators

Click linked name(s) to expand/collapse or show everyone's info
  • Tom Swan
  • Chad Blair

Research

Hypothesis:

Our hypothesis for this research is that LCLTT structures such as BDAs will increase the following: available soil moisture, forage production, and the prevalence of wetland and facultative wetland plant species such as prairie cordgrass near the stream.

Materials and methods:

General Approach

This project builds upon a pilot project implemented by TNC in 2020 to restore riparian health in prairie streams in western South Dakota using LCLTT such as BDAs. The overall goals of our project are to increase awareness and adoption of riparian restoration programs by 1) providing critical research on LCLTT and impacts on forage production, plant community composition, and soil moisture and 2) conducting outreach and extension activities for producers on site selection, materials, and construction techniques for implementing LCLTT restoration techniques on their operation.

Intended Audience: The intended audience for this proposal includes technical experts (federal, state, NGO, university partners) and livestock producers within the NCR.

Site Selection: Research for this project will take place on five producer ranches as well as the SDSU Cottonwood Field Station (CFS) located near Philip, SD. The CFS is used primarily for livestock grazing and lies within a Northern Mixed Grass Prairie ecosystem. Topography of the station is gently sloping with long, rolling hills and relatively flat-topped ridges. The CFS lies within the Pierre Shale Plains major land resource area (MLRA) (MLRA 60A). Soils of the mixed-grass prairie research pastures are predominantly Kyle and Pierre clays developed from the Pierre formation (shale). Cottonwood Creek is an intermittent stream within the Bad River watershed and meanders through approximately 3 miles of the CFS boundary across 4 pastures. Long-term (>40 years) livestock grazing within pastures containing Cottonwood Creek has resulted in stream bank erosion, channel incision, and head-cutting, impairing riparian function throughout the property.

In 2019, TNC developed a web-based tool (missouriheadwaterstool.org) to foster collaboration at a watershed scale to enhance riparian health efforts among partners in Western South Dakota, North Dakota, Montana, and Wyoming. The tool aggregates spatial datasets such as ecological sites, rangeland potential, hydrologic data, elevation, slope, and satellite imagery to help identify intactness, erosion potential, drought vulnerability, and resilience of riparian areas. This tool will be used to identify riparian areas on cooperator ranches with the highest potential for enhancement using LCLTT. Cooperator ranches will be located within MLRA 60A to minimize differences in soil type and land potential allowing for comparison of results between sites. Data collection is the same for Research and Demonstration aspects of this project, and for simplicity, is described only once.

1. Research

Hypothesis: LCLTT will increase riparian vegetation, biomass production, and soil moisture content compared to untreated stream reaches.

Restoration Treatments: Six stream reaches suitable for riparian restoration will be identified at each site (CFS and the 5 producer ranches). Stream reaches will be randomly allocated into a control (no restoration) and a LCLTT. This will be a complete randomized block design with producer ranches as blocks and reaches as the experimental unit.

Vegetation Data Collection: Along each of the 6 stream reaches per site, three vegetation transects will be established and measured prior to the LCLTT implementation to collect baseline vegetation data. Vegetation transects (50 m) will be established perpendicular to the stream channel and span the valley bottom width. Along each transect, a pin flag will be dropped every 50cm and all plant species that contact the pin flag will be recorded. Vegetation transects will be measured in the summer of Years 1, 2, and 3. Data from the plant transects will be used to analyze species composition within riparian areas to compute similarity indexes between current vegetation composition and historical states as defined by ecological site descriptions. Data will be statistically analyzed for treatment effects within and between years.

Vegetation biomass will be evaluated using 0.25 m2 permanent plots; 3 plots will be randomly located in each stream reach segment within the floodplain area. Livestock exclusion cages will be used to protect plot vegetation from grazing. Plots will be evaluated once each growing season in Years 1, 2, and 3 during peak biomass production (July-August). Data collected in each plot will include: 1) a complete species list, 2) percent cover for each species, 3) height of each species, and 4) non-destructive biomass estimates of each species using a double sampling technique. Biomass composition (based on biomass and cover), species richness, and a Shannon-Weiner diversity index will be derived from the plot data. Response variables will be statistically analyzed for treatment effects within and between years.

Within each stream reach, two photo monitoring points will be established at opposite ends of the reach. Digital photographs will be taken at each photo point during biomass sampling. Photo monitoring is a valuable qualitative tool for documenting current conditions of a site as well as tracking changes due to treatment or management differences. Photo point data will be used for demonstration and extension materials.

Soil Moisture Data Collection: State-of-the-art sensors for soil water content, soil temperature, and soil electrical conductivity will be used to determine seepage of soil moisture at 0, 6, 12, and 18-inch depths at two locations (1 LCLIT and 1 Control) at each site. Soil moisture will be collected using probes for measuring soil volumetric water content (e.g. HOBOnet Multi-Depth Soil Moisture Sensor, Bourne, MA). Soil probes will be installed 10 m from the edge of the stream channel within the flood plain. Once installed, the sensors will record measurements at 15-minute time intervals for the entire study period. Sensors will be connected to a wireless network to allow data to be received and downloaded from a central location. Differences in soil moisture will be statistically analyzed for treatment effects within and between years.

 

Methodology for the Outreach and Extension activities are described below in the appropriate section.

Research results and discussion:

Research objective: Research LCLTT’s impact on forage production, plant community composition, and soil moisture.

 

Research progress as of 12/31/2022:

  • We hired a Graduate Research Assistant, James Bolyard. James started January 2022. James was born and raised in southwestern Michigan. After spending several years pursuing medical studies, he graduated from Northern Michigan University in 2015 with a B.A. in Environmental Science, whereupon he spent much of the next six years working with AmeriCorps, NGOs, and various Federal agencies as a seasonal employee in several capacities. James comes to this project with extensive working knowledge of LCLTT for riparian restoration and has been a great addition to the project's team. 
  • We established 4 sites in 2022; the watershed size above sites varies from 12 km2 to 460 km2. The associated Major Land Resource Area (MLRA) is noted.
    • BLM1, Upper Battle Creek - MLRA 60A.
    • BLM2, Lower Battle Creek - MLRA 60A.
    • PRV1, Newell (SD) Producer - MLRA 60A.
    • Cottonwood Field Station, South Dakota State University (SDSU) Cottonwood Field Station - MLRA 63 A.
  • Several additional producer sites were identified in 2022, but due to limited access (i.e., producer operations are located on "gumbo" - sticky, high clay soils that make it difficult to access the site unless it is dry) we were unable to complete any LCLTT installation. These sites are now priority for the 2023 field season.
  • At each site, the stream width was measured at 20 random points. A stream reach was defined as the stream length equal to 20 average stream widths. Three (3) control reaches were located upstream, and 3 treatment reaches were located downstream. This experimental design was to avoid confounding the effects of the treatment reaches and also included a minimum of 2 reaches as a buffer between the end of the control reaches and the start of the treatment reaches (Figure 1).
    A map of a stream showing pink lines for treatment reaches where low cost, low tech structures are installed and control reaches upstream.
    Figure 1. The SDSU Cottonwood Field Station site. Pink lines indicate treatment stream reaches were structures were installed and blue lines indicate control reaches that lack interference.
  • 1.08 miles of stream - this includes the stream reach equivalent above each treatment reach that should see at least some improvement from implementation of the structures. 
  • 28 structures were built across all sites (Figure 2).
    • Structures were installed by AmeriCorps crews in June and July 2022. A mixture of beaver dam analogs (BDAs) and post-assisted log structures (PALs) were used, depending on available materials and site conditions. 
    • Structures range from <0.3 m to ~ 1.3 m tall and <1 m to >4 m wide.
A large, downed tree with people standing in front of it that are installing a riparian structure using posts and woody debris.
Figure 2. The AmeriCorps crew utilizing a large, downed tree as a base for a post-assisted log structure using locally available woody debris.
  • Soil moisture probes were installed.
    • We are using 45 cm long Hobo Multi-depth soil probes that do soil moisture readings at 0-15 cm, 15-30 cm, and 30-45 cm depths. 
    • Two probes at each site - 1 probe in a treatment reach and 1 probe in a control reach.
    • Readings every 15 min, with broadcast to the cloud every 1 hr.
  • Plant community data was collected.
    • 50 m transects, 4 transects per reach using the line-point intercept technique
    • Non-destructive biomass estimates were collected from 0.5 m2 plots; 3 plots per reach
  • We have had notable early success at the SDSU Cottonwood Field Station!!
    • We installed structures at Cottonwood in July 2022. Figure 3 shows a yellow line, which is where one of our structures was located. We received several inches of rain, causing a few structures - including the one denoted by the yellow line - to blow out. At the same time, we noticed signs of beaver activity on the stream! The beavers reestablished themselves at Cottonwood and built several beaver dams themselves, one of which is noted by the red line in Figure 3 and a close up is provided in Figure 4. Figure 3 clearly demonstrates the benefit of LCLTT such as BDAs in slowing and holding water on the landscape, which is further benefitted by beaver recolonizing the area.
    • Of note is that LCLTT structures are not meant to be permanent - instead, they are designed to do exactly what occurred at Cottonwood. The slowing and holding of water on the landscape resulted in water being backed up on Cottonwood Creek further than it has ever been documented before - well into September.

Three aerial views of Cottonwood Creek, showing where LCLTTs have been implemented and the resulting natural development of a beaver dam by new beaver activity.
Figure 3. Three aerial views of Cottonwood Creek, showing where LCLTTs have been implemented (yellow line) and the resulting natural development of a beaver dam (red line) by new beaver activity. The resulting pool between the man-made structure and the beaver made structure is approximately 2 m deep of water.
A natural beaver dam in Cottonwood Creek.
Figure 4. An up close image of the natural beaver dam located in Cottonwood Creek. This beaver dam is noted by the red line in Figure 3. The structure we installed is to the right, around the bend.

 

Anticipated research activities in 2023:

  • Finish site selection
    • Install structures on new sites
  • Conduct plant community assessments, including biomass
  • Check on soil probe functionality and re-establish connection, if needed
  • Structure maintenance on existing sites

 

Research progress as of 12/31/2023:

Field Work

BLM1

            Several of the LCLTT structures at BLM1 suffered damage from high flows and livestock during winter 2022 - spring 2023, but the remaining structures showed considerable signs of success. Surviving structures often had considerable sediment capture on their upstream side, causing stream bed aggradation and improving floodplain connectivity. However, this increased connectivity caused notable erosion issues on side channels, including several headcuts. These issues were addressed by implementing additional LCLTT structures during the planned maintenance in early June 2023, and the structures had largely filled in with sediment within a few weeks, reversing the headcuts and creating a wet meadow area with multiple small pools (Figure 1, 2023). While not formally counted, increased numbers of amphibians, reptiles, and nesting/brooding waterfowl were seen in LCLTT treatment areas.

 

A headcut was treated with LCLTT and subsequently largely filled in with sediment.
Figure 1, 2023. A headcut was treated with LCLTT and subsequently largely filled in with sediment.

BLM2

            Structures on the BLM2 site were minimally damaged during winter 2022 - spring 2023. Most structures showed considerable sediment capture and, in less incised locations, considerable improvement in floodplain connectivity (Figure 2, 2023). Existing structures were repaired where necessary and expanded either vertically or laterally to continue to improve their results, and new structures were built to capitalize on changes to the stream in the hopes of reconnecting avulsed side channels and meanders. Livestock were present on BLM2 for much of the spring and summer, and as conditions dried animals showed a preference for treatment areas, which maintained surface water longer than untreated areas did. As with BLM1, there was an increased number of amphibians and reptiles on BLM2.

An example of a BDA that has captured sediment and improved floodplain connectivity.
Figure 2, 2023. An example of a BDA that has captured sediment and improved floodplain connectivity.

Cottonwood Field Station

            The heavy snows of winter 2022-2023 and the subsequent high flows and debris damaged or destroyed most of the LCLTT structures at Cottonwood Field Station (CFS) (Figure 3, 2023) and damaged the naturally occurring beaver dam that was created in one of the treatment areas in 2022. New structures were installed, using coarser heavier materials and lower profile structure designs than were used previously to see if they hold up better to the high flows and debris produced by Cottonwood Creek. A South Dakota State University fisheries biologist did a preliminary survey of the treatment reaches and counted 16 species of fish, including native prairie stream species such as bullhead, sunfish, and redfin shiners, some of which were spawning in the treatment areas. This is a promising indicator of the potential for these areas to serve as production areas and reserves for such species if LCLTT can be used to maintain either continuous surface water or pools that last throughout the year.

The LCLTT structures on CFS performed well until high flows and debris destroyed them.
Figure 3, 2023. The LCLTT structures on CFS performed well until high flows and debris destroyed them.

By the time LCLTT maintenance and construction could occur, the beavers had largely repaired their dam, and it was decided to have the maintenance crew reinforce the structure with untreated wooden posts (Figure 4, 2023). The crew moved piles of flood debris from the bank into the beaver pond, which the beavers then integrated into their dam over the next few days. As water levels in the stream dropped, it became apparent that the dam had captured ~ 1 meter of sediment in the pond above it since its creation, largely filling it. This amount of sediment capture reframes what may be possible with LCLTT on streams of this size and level of incision if structure designs that can hold up to the flows and debris are identified. This could, potentially, make the re-establishment of historic floodplain connectivity a viable option in some areas rather than being limited to creating an inset floodplain.

A natural beaver dam that has been reinforced by wooden posts. Note the sediment level above the dam compared to the water level below it.
Figure 4, 2023. A natural beaver dam that has been reinforced by wooden posts. Note the sediment level above the dam compared to the water level below it.

PRV1

            The structures of PRV1 were slightly to moderately damaged during winter 2022-2023 but showed appreciable sediment capture by spring 2024. Before maintenance could be done, a major rain event occurred (>3 inches of rain in 48 hours, according to a local rancher), causing severe flooding. While a few structures were lost in this event, some of the surviving structures filled in with sediment and immediately improved floodplain connectivity, while others caused desired changes to stream and floodplain morphology - which had been anticipated to take years – over the course of a weekend (Figure 5, 2023). The remaining structures were repaired and expanded, as needed, and new structures were implemented to take advantage of the changed stream morphology.

PRV1 before and after flooding. Note the large sediment deposit that has smoothed and leveled the stream’s connection to its floodplain.
Figure 5, 2023. PRV1 before and after flooding. Note the large sediment deposit that has smoothed and leveled the stream’s connection to its floodplain.

PRV2

            PRV2 is the newly created demonstration site for the project and is located on a private ranch in Butte County, SD (Figure 6, 2023). Located on a seasonal to intermittent stream, this site has numerous areas of incision and entrenchment, and it is largely disconnected from its floodplain. LCLTT construction occurred in June of 2023. A wider variety of structures were used on this site compared to others, including wicker weirs, post vanes, and bank-attached PALS. Within weeks of installation, summer rains produced enough flow and sediment transport to fill in many of the smaller structures and notably enhanced some areas.

Entrenched section of PRV2. Note the remnants of the inset floodplain and steep sides of the bench.
Figure 6, 2023. Entrenched section of PRV2. Note the remnants of the inset floodplain and steep sides of the bench.
Participation Summary
2 Farmers participating in research

Project Activities

Producer Meetings
Extension article series on riparian restoration
Presentations
Research - Year 1
Workshops and Field Days
Research - Year 2

Educational & Outreach Activities

3 Consultations
1 Published press articles, newsletters
6 Webinars / talks / presentations
3 Workshop field days

Participation Summary:

40 Farmers participated
10 Ag professionals participated

Information Products

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and should not be construed to represent any official USDA or U.S. Government determination or policy.