Legler School Branch and Pioneer Valley Branch Targeted Watershed Assessment: A Water Quality Report to Restore Wisconsin Watersheds
James Amrhein, Water Quality Biologist, Southern District Wisconsin Department of Natural Resources.
Public Review Draft
In 2010, the Green County Land Conservation Department approached the department about conducting projects to address issues within the riparian corridor and the sub-watersheds as a whole. They received a state Targeted Runoff Management (TRM) grant address non-point source pollution issues in the watersheds. They also received a companion grant from the Environmental Protection Agency to address nutrient loading to both systems as well as funding from the Natural Resources Conservation Serviceï¿½s (NRCS) inaugural National Water Quality Initiative (NWQI) program.
As part of the project, the department agreed to conduct a TWA project to monitor habitat, biology, and nutrient concentrations in each subwatershed prior to, and after, implementation of best management practices (BMPs). It would have been desired to collect multiple years of pre-implementation data to establish a better baseline and increase the statistical robustness of the dataset. Unfortunately, because implementation of BMPs was set to begin in fall of 2012, this was not possible.
During the months of May through October 2012 the department monitored stations on Legler School Branch, Pioneer Valley Creek and Krieg Valley Creek. The priorities for this work were to gather pre and post implementation monitoring data to identify the effectiveness of best management practices.
Beginning in fall 2012, and continuing over the next 2 years, the Green County Land Conservation Department (LCD) spent nearly $630,000 on installation of BMPs throughout the 2 sub-watersheds (Tables 2 and 3). Nearly 6500 feet of livestock fencing, 320 feet of stream crossing, and 17 acres of critical area stabilization were implemented. Additionally, over 16,500 feet (3.12) miles of stream was rehabilitated: 8500 feet on Legler School Branch; 3325 feet on Pioneer Valley; and 4700 feet on Krieg Valley Creek. This rehabilitation included removal of dense stands of nuisance (box elder) trees which tend to shade out grasses and forbs and destabilize the banks as they fall in the stream. After tree removal, the banks were sloped, shaped and seeded in native grasses. Habitat structures such as Little Underwater Neighborhood Keepers Encompassing Rheotactic Salmonids (LUNKERS) were placed in bends on the stream and rock weirs were used on straight sections to create plunge pools for generating deeper water areas.
The Project Area
Little Sugar River (SP14)
The project is located in the Little Sugar River Watershed within the Sugar Pecatonica Basin. This area is largely rural. The natural communities of Legler School and Pioneer Valley are considered cold systems, but should be confirmed as cold. Legler School Branch and Pioneer Valley Creek are two streams that originate west of the Village of New Glarus and flow through north central Green County to join the Little Sugar River. Both creeks have similar sized watersheds and land uses, primarily grassland / pasture, followed by agriculture and forest.
About the Watershed
The Little Sugar River watershed contains a number of quality streams that wind their way through the rolling hills of north central Green County and a small portion of southern Dane County. The ridges of the western portion of the watershed are more pronounced, producing spectacular pastoral scenery, but also increasing the potential impact from runoff. The area is predominantly agriculture, especially dairy, cash crop, and feeder operations.
The population of the watershed is not predicted to grow significantly in the next two decades although there has been an increase in the number of houses in the area surrounding New Glarus.
Both Legler School Branch and Pioneer Valley Creek are currently on the states 303(d) list of impaired waters because of habitat loss due to sedimentation. As of this study, Krieg Valley Creek, a tributary of Pioneer Valley Creek, is not on the impaired waters list. A 2004 survey of one site on Legler School Branch showed the presence of large numbers of mottled sculpin, a coldwater indicator species, as well as several specimens of brown trout. According to a 2003 basin report (WDNR, 2003), Pioneer Valley Creek contained only small numbers of nongame (forage) species. Despite these limited surveys, the department felt both systems would respond favorably to watershed and riparian stream work. Both streams are tributaries to the Little Sugar River, which is a Class II trout stream, and both receive a majority of their water from spring flow and groundwater seepage.
Additional Resources, Information
Site Selection & Study Design
Nine sites were monitored in the project area -- five on Legler School Branch, three on Pioneer Valley and one on Krieg Valley Creek.
Because the Wisconsin Stream model (Lyons, 2008) predicted the entirety of all three waters to be cold systems, the coldwater index of biotic integrity (IBI) developed by Lyons, et. al. (1996) was applied to all sites. In the 2011 and 2012 surveys, brown trout and mottled sculpin, both coldwater indicator species, were the predominant species at all sites on Legler School and Pioneer Valley. The coldwater IBI reflected this assemblage and was consistently 60 (good) at most sites. The site on Krieg Valley did not yield any fish. In 2017, white suckers, a thermally transitional and tolerant species, became a predominant at the STH 69 and ?Private 1? sites on Legler School Branch. They were also present in moderate numbers at another site upstream. Several other species were also noted in 2017, but in low numbers or individual specimens. The exception was brook stickleback which was the major species at a Legler Road site on Legler School Branch. The species assemblage remained essentially unchanged on Pioneer Valley Creek. Krieg Valley now had mottled sculpin in addition to the stickleback, whereas it contained no fish in 2012. Coldwater IBIs for the 2017 surveys were more variable, ranging from 20 (Poor) to 60 (good).
Quantitative habitat surveys conducted at 2 sites on Legler School Branch and 2 on Pioneer Valley Branch showed an increase in overall score on the 2 Legler School sites and at 1 site on Pioneer Valley (Table 6). It should be kept in mind that no habitat work was done on the Pioneer Valley sites. The Legler School Branch showed improvement in mean bank erosion at both sites and in width-to-depth ratio at the ?Private 1? site. Fish cover dramatically improved at both Legler sites. Pioneer Valley sites improved, most substantially at the Pioneer Valley Road site, which had increased scores for mean buffer width and percent fish cover. Both increases were likely coincidental and not due to any management actions.
Qualitative habitat assessments were repeated at 3 sites, 1 each on Legler School, Pioneer Valley, and Krieg Valley Creek. There were also 2 other sites qualitatively assessed in 2017 on Legler School Branch (Table 7). Legler School at Private 3 improved, even though no habitat work was done. This was mainly due to an increase in buffer width score owing to the fact that cattle have been taken out of the wet meadow adjacent to the stream. The site on Pioneer Valley was essentially unchanged with slight difference in the riffle score, likely due to the subjective nature of this type of habitat assessment. Krieg Valley had the biggest improvement ? 15 (poor) to 50 (good) because substantial work was done to shape, slope, and stabilize the banks of the creek. Two other sites on Legler School that were not previously assessed (Private 3 and 4) showed similar overall scores and individual metrics as other sites in these systems.
Nutrient monitoring conducted in 2012 was not repeated in 2017 as weather conditions were markedly different. As previously mentioned, 2012 was a drought year that presented few opportunities for runoff, and thus nutrient loads were suppressed. One problem this presents is that the pre-implementation concentrations may not represent a normal situation, thereby making comparisons with post-implementation measurements difficult, especially in the absence of flow data. Although implementation of BMPs will possibly improve water quality over the long-term, concentration-based data may not reflect these improvements because of differences in flow. In 2017, the months of May, June, July, and October were wetter than average (Wisconsin State Climatology Office, 2018), making any comparison to 2012 data irrelevant in the context of improvements in the watershed.
Macroinvertebrate sampling was not conducted in 2011/2012; however, previous macroinvertebrate data collected on both Legler School and Pioneer Valley showed the stream to be in good condition (WDNR, unpublished data). The historic macroinvertebrate IBIs (Weigel, 2007) were in the good to excellent range, while the Hilsenhoff Biotic Index (HBI) (Hilsenhoff, 1987) showed no to only slight possible organic loading. The 2017 data was very similar.
Legler School Branch and Pioneer Valley Creek have been on the states 303(d) list of impaired waters since 1998 because of habitat degradation caused by sedimentation. Pre-rehabilitation quantitative habitat sampling revealed percent fines made up over 80% of the stream channel. Despite this, both systems supported a coldwater fishery, including some evidence of natural reproduction given the presence of young-of-the year fish. However, one could surmise that numbers of fish were limited because of the sediment and overall lack of fish cover and spawning habitat in the creeks.
The riparian stream rehabilitation portion of the project enhanced over 3 miles of stream ? 1.6 miles on Legler School Branch; 0.6 miles on Pioneer Valley Creek and 0.9 miles on Krieg Valley Creek. Some general observations can be made about the systems as a whole. While soft sediment was reduced, quantitative habitat surveys show it still makes up over 50% of the streams bottom. Qualitative habitat monitoring revealed similar results. The stream projects did improve fish habitat and reduced bank erosion. The fisheries are still made up majorly of brown trout and mottled sculpin.
A comparison of pre-and post-biological conditions was difficult because there was essentially only 1 year of opportunity to measure baseline conditions. Also, because participation was voluntary, it was unknown exactly where stream and watershed work would be done. Therefore, there are only a limited number of sites where riparian stream work could be directly compared and both of those (STH 69 and Private 1) are on the lower reaches of Legler School Branch. While one can compare the effects of the habitat rehabilitation on the fishery of those particular stretches of stream, it is difficult to determine if the project had an impact on trout populations in the streams overall.
Conclusions and Recommendations
Riparian stream corridor improvement had the desired result of reducing streambank erosion and improving fish habitat. While wide variation in trout population and size structure was observed at various sites in both systems where riparian stream work was not done, it was consistently evident that the rehabilitation project was successful in increasing numbers of trout for those areas where the work was done. The numbers of yearling and adult trout in these rehabilitated sections was comparable (26th to 50th percentile) to other streams in the driftless region. However, it is difficult to determine the long-term effects of the watershed and riparian projects on the water quality and fishery of these streams, especially given the scattered nature of the work.
The full potential of these streams with regards to trout biomass may be limited by natural factors such as size and flow. It may also be limited by the residual effects of habitat degradation. Excessive sedimentation continues to be an issue in all the surveyed streams, with fine sediments making up well over 50% of the stream bottom. Given relatively low flow and gradient of the streams, it is unknown how long these legacy sediments will remain especially since reduction of inputs from fields and pastures was not emphasized and bank erosion was mitigated at a minority of stream miles and only along the mainstem. The scattered nature of BMP implementation in watershed projects such as these makes it difficult to determine if these had any impact on the water quality. As was noted during an evaluation of Priority Watershed Projects from 20 to 30 years ago by Kroner et. al., (1992), localized improvements were noted where specific practices were implemented, but overall stream improvements were less than successful due to the relative lack of participation, the scattered nature of implementation, and masked by uncontrolled non-point pollution sources.
While quantitative habitat surveys can help track the level of fine sediment on the stream bottom, the proper way to determine if implementation of BMPs had significant impact on streams would be by determining loads during base flow and runoff events. This could only be achieved by installation of a USGS flow gage which could monitor flows and automatically sample at given interval during baseflows and throughout a hydrologic curve during events. It is only through this robust sampling that one can determine if there has been significant reduction in nutrient and sediment loads. In the absence of this data, resource managers will have to rely on more subjective outcomes to determine if conditions and water quality have improved.
One might think this would be case for keeping the streams on the impaired waters list. However, the compendium of evidence from both a biological and habitat sense suggests that both Legler School Branch and Pioneer Valley Creek are meeting their attainable use. As evaluated as the coldwater systems they are purported to be, the IBIs are favorably in the fair to good category. IBI scores are consistently in the 40 to 60 range, keeping in mind that brown trout streams can only achieve a maximum score of 80 (not 100) in the absence of brook trout. The macroinvertebrate community is healthy and indicates good water quality. Habitat assessments for sites that were rehabilitated, as well as for those that were not, are consistently in the good range. Therefore, the department recommends that both Legler School Branch and Pioneer Valley Creek be removed from the state?s 303(d) list of impaired waters.
If they so desire, the Green County Land Conservation department should seek opportunities to work with more riparian landowners to improve habitat or protect the riparian corridor. It would be likewise desirable to complete the watershed project, keeping in mind that whole-sale projects like these should be made from the ground up with a full watershed approach, and buy-in from landowners beforehand. There are examples of projects that were very successful at achieving true water quality improvements throughout the system. In those cases, sediment and nutrient loads were significantly reduced and the fishery showed great improvement at all sites in the streams (Carvin, et. al., 2018; TNC, 2014).
For systems like Legler School Branch and Pioneer Valley Creek, which have the potential to be a quality cold water resources (i.e. a trout stream), work in both the riparian corridor and in the watershed is important. As this and other projects have demonstrated, riparian work will result in more immediate improvement in the fishery, which is visible to the public and will garner more support for such efforts. Work in the watershed protects the investments made in the riparian corridor. Implementation of BMPs and promotion of soil health practices can improve infiltration, which reduces sediment and nutrient runoff. Work in barnyards, and pastures along with proper manure management can prevent catastrophic losses of the fishery due to runoff events.
The DNR should return to Legler School Branch and Pioneer Valley Creek as part of the fisheries trout stream rotation scheduled for 2021. Some sites should be repeated, while sites where stream corridor work has been conducted should be surveyed, especially on Pioneer Valley Creek. Fisheries can then decide if these systems meet the criteria for classifications as trout water.
The natural communities of Legler School and Pioneer Valley should be confirmed as cold systems.
The designation for Krieg Valley Creek should be updated to reflect its status as a cold-transitional (cool-cold) headwater.
Monitoring and Planning
The study area has been monitored multiple times through the years, with the reports and plans providing amendments to the Sugar Pecatonica Basin Plan and the state's Areawide Water Quality Management Plan. For more information about this area, review the Sugar Pecatonica Basin, as well as the online watersheds which reflect water quality plans prepared in previous years.
See also Little Sugar River Watershed Monitoring & Planning
Related Studies, Plans
In 2011, a site had already been sampled on Legler School Branch (Private 3) in 2011 for fish and qualitative habitat. For the 2012 survey, biologists conducted fish and quantitative habitat monitoring on 2 sites on Legler School Branch - at STH 69 and upstream of 2nd Avenue on private property (Private 1). Fish and quantitative habitat monitoring was conducted at CTH O and Pioneer Valley Road on Pioneer Valley Creek. An additional site (off Klassy Road) was sampled on Pioneer Valley in 2012 for fish and qualitative habitat. A site on Krieg Valley several hundred meters upstream of its confluence with Pioneer Valley Creek was also sampled.
Water chemistry grab samples were taken at CTH O on Pioneer Valley and 2nd Street in the Village of New Glarus on Legler School Branch. Samples were collected bi-monthly beginning in the middle of May until the end of October and analyzed for total phosphorus and nitrogen. This meets and exceeds the requirements for determining phosphorus impairment as outlined in the most recent update of the Wisconsin Consolidated Assessment and Listing Methodology (WisCALM) (WDNR, 2017).
Flow data was not collected for this study. It is imperative to note that a region wide drought occurred during the summer of 2012. Cumulative rainfall for the study period was approximately 8 inches below average (Wisconsin State Climatology Office, 2018).
The 2017 study was conducted by water resources biologists at the same sites as in 2011/12 as well as at 2 additional sites on Legler School Branch where stream rehabilitation had taken place. These sites were sampled for fish and qualitative habitat.
For all sites, the fisheries assemblage was determined by electroshocking a section of stream with a minimum station length of 35 times the mean stream width (Lyons, 1992). A stream tow barge with a generator and two probes was used at most sites. A backpack shocker with a single probe was used at sites generally less than 2 meters wide. All fish were collected, identified, and counted. All gamefish were measured for length. At each site, qualitative notes on average stream width and depth, riparian buffers and land use, evidence of sedimentation, fish cover and potential management options were also recorded. The quantitative and qualitative habitat surveys were conducted according to Simonson, et. al. (1994). Macroinvertebrate samples were obtained at 7 sites by kick sampling and collecting using a D-frame net in fall, 2017 and sent to the University of Wisconsin-Stevens Point for analysis.
For more information, search Explore Your Waters! for river, stream, lake, watershed and basin detail. Updated summaries are available for waters in this study.
Carvin, Rebecca, L.W. Good, C. Diehl, K. Songer, K.J. Meyer, J.C. Panuska, S. Richter, and K. Walley. 2018. Testing a two-scale focused conservation strategy for reducing phosphorus and sediment loads from agricultural watersheds. Journal of Soil and Water Conservation. 73(3): 298-309.
Hilsenhoff, William L. 1987. An Improved Biotic Index of Organic Stream Pollution. The Great Lakes Entomologist. 20: 31-39.
Kroner, Ron, J. Ball, and M. Miller. 1992. The Galena River Priority Watershed Project: Bioassessment Final Report. Wisconsin Department of Natural Resources Publication WR-306-92. May 1992.
Lyons, John. 1992. Using the Index of Biotic Integrity (IBI) to Measure Environmental Quality in Warmwater Streams of Wisconsin. United States Department of Agriculture. General Technical Report NC-149.
Lyons, John, L. Wang, and T. Simonson. 1996. Development and Validation of an Index of Biotic Integrity for Coldwater Streams in Wisconsin. North American Journal of Fisheries Management. 16:241-256.
Lyons, John. 2008. Using the Wisconsin Stream Model to Estimate the Potential Natural Community of Wisconsin Streams (DRAFT). Wisconsin Department of Natural Resources Fish and Aquatic Life Research Section. November 2008.
Lyons, John. 2015. Methodology for Using Field Data to Identify and Correct Wisconsin Stream ï¿½Natural Communityï¿½ Misclassifications. Version 5. May 29, 2015.
Simonson, Timothy D., J. Lyons, and P.D. Kanehl. 1994. Guidelines for Evaluating Fish Habitat in Wisconsin Streams. U.S. Department of Agriculture. Forest Service. General Technical Report NC-164.
TNC. 2014. Targeting Conservation Practices Within a Watershed: Lessons Learned from the Pleasant Valley Project. The Nature Conservancy. Pecatonica Webinar Final. By Steve Richter and Laura Ward Good. http://cswea.org/wpcontent/uploads/2017/09/4_Richter-and-Good-Pecatonica-webinar-final-1-1.pdf
WDNR. 2003. The State of the Sugar and Pecatonica River Basins. Wisconsin Department of Natural Resources.
WDNR. 2017. Wisconsin 2018 Consolidated Assessment and Listing Methodology (WisCALM). Clean Water Act Section 305(b), 314, and 303(d) Integrated Reporting. Wisconsin Department of Natural Resources. Bureau of Water Quality Program Guidance. September 2017.
Weigel, Brian. 2003. Development of Stream Macroinvertebrate Models That Predict Watershed and Local Stressors in Wisconsin. Journal of the North American Benthological Society. 22(1): 123-142.
Wisconsin State Climatology Office. 2018: http://www.aos.wisc.edu/~sco/clim-history/7cities/madison.html#Precip