CONTINUATION PROJECT FINAL REPORT. Funded by the Minnesota Pollution Control Agency Clean Water Partnership Project

Transcription

1 REHABILITATION MIDDLE SAUK RIVER CONTINUATION PROJECT FINAL REPORT Funded by the Minnesota Pollution Control Agency Clean Water Partnership Project SUBMITTED BY:: SAUK RIVER WATERSHED DISTRICT SEPTEMBER 2009

2 Contributing Project Sponsors: Sauk River Watershed District Stearns County Soil and Water Conservation District Stearns County Natural Resources Conservation Service Stearns County Environmental Services BWSR Joint Powers Engineers Todd County Soil and Water Conservation District Todd County Natural Resources Conservation Service Todd County Planning and Zoning Department Sauk River Chain of Lakes Association Minnesota Department of Natural Resources Minnesota Pollution Control Agency US Fish and Wildlife Service Friends of the Sauk River Minnesota Waters MN Extension Service City of Melrose 1

3 Table of Contents Contributing Project Sponsors... 1 List of Figures... 2 List of Tables... 2 List of Appendices... 2 Executive Summary... 3 Project Summary... 6 Completed Priority Management Projects... 7 Monitoring Summary Stream Modeling Results BMP Operation and Maintenance Plan Conclusion Reference List of Figures: Figure 1: Middle Sauk River Rehabilitation Project Area... 6 Figure 2: Middle Sauk River Rehabilitation Project Objectives... 7 Figure 3: SRCL Morphological Data Figure 4: Sauk River Chain of TSI for Lake Flowage Lakes Figure 5: Sauk River Chain of Lakes TSI for Non-flowage Lakes Figure 6: Horseshoe Lake Summer Avg. TP Concentration: Figure 7: Total Precipitation March-September Figure 8: Sauk River at Richmond: Avg. Daily Flow Figure 9: Richmond Site: TP Flow Weighted Mean Conc. Vs. Annual Mean Flow Figure 10: Total Phosphorus Load Comparison of High and Avg. Flow Years Figure 11: Avg. TP Conc. At Richmond and Cold Spring Figure 12: Getchell Creek Total Suspended Solids Flow Weighted Concentrations Figure 13: Unnamed Creek Summer Average TP Concentrations Figure 14: Unnamed creek Summer Average TSS Concentrations Figure 15: Stoney Creek Total Suspended Solids Flow Weighted Concentrations List of Tables Table 1: Annual Precipitation Data from the Melrose/New Munich Area Table 2: North Central Hardwood Forest Stream Ecoregion Data (MPCA) Table 3: Total Phosphorus Modeling Summary Table 4: Total Suspended Solids Modeling Summary Table 5: Getchell Creek Flux Modeling Results Table 6: Stoney Creek Flux Modeling Results Table 7: Adley Creek TP and TSS Summer Average Concentrations List Of Appendices Water Monitoring Data... Appendix A Project Field Notes... Appendix B FLUX Data... Appendix C MPCA Sauk River Chain of Lakes Update... Appendix D 2

4 EXECUTIVE SUMMARY The Middle Sauk River region located in central Stearns County has been impacted by nutrient and sediment loading as a result of land use management practices and changes. The 1985 and 1993 Diagnostic Studies on the Sauk River Chain of Lakes identified the Sauk River as the primary source of water and the largest nutrient contributor to the Chain of Lakes. The MPCA 1985 study indicated that the Sauk River watershed contributed 97% of the Total Phosphorus to the 14-lake system. In 2004, the Sauk River Chain of Lakes were listed on the MPCA s list of impaired waters. Data from the last five years indicates that nutrient concentrations in the Sauk River at Richmond, MN resemble ecoregion averages during dry years. However, during the wet years significant increases in nutrient levels have been recorded. Additionally the Sauk River Watershed District s (SRWD) monitoring anchor sites installed on the Sauk River identified a significant pulse of nutrients and sediment occurring from the Sauk Lake outlet to the County Road 12 station near St. Martin. This identified area makes up the majority of the Middle Sauk River region which includes the sub-watersheds Getchell, Unnamed, Stoney and Adley Creeks. Getchell, Unnamed and Stoney Creeks were identified as nutrient contributors to the Sauk River during the MPCA 1985 Limnological Study. The goal of the Middle Sauk River Rehabilitation Continuation Project was to reduce nutrient and sediment loading from eroding riparian areas and cropland, runoff from farm sites and leachate from septic systems. The BMPs to be implemented were considered cost effective improvements especially if benefits are assessed over a twenty year time period. In more recent years, lakeshore development has converted forested areas and agricultural land to homes, roads, driveways, or other impervious surfaces. This increased runoff transports phosphorus enriched water and sediment to the Sauk River and the Chain of Lakes. The SRWD worked with the local shoreland governing agencies and Stearns County Shoreland specialist, Greg Berg, to assist shoreland owners in restoring their eroding shoreline and/or establishing vegetative buffers. Within the SRWD there are 1744 registered feedlots, of which 1081 feedlots are within the Middle Sauk River area. One of the primary objectives of the Middle Sauk River Rehabilitation Continuation Project was to work with the agricultural producers in the middle Sauk River region and assist them in applying conservation practices. Stormwater runoff from the small communities within the middle Sauk River region was also a focus area. Efforts were made to educate and assist the community decision makers to address their urban runoff before it makes it way to the Sauk River. The primary objective of the Middle Sauk River Rehabilitation project was to work with area landowners to address the water quality concerns of the Sauk River and its tributaries; and to assist them in implementing BMPs to reduce nutrient runoff to the Sauk River. This rehabilitation project had a three year implementation plan designed to address pollution contribution in the Sauk River and its four primary tributaries. Priority was given to feedlots, vegetative buffer strips, riparian erosion issues, and septic concerns. The SRWD staff and partnering agencies, environmental organizations and individuals accomplished the following activities as a result of this Clean Water Partnership Implementation Project: Animal Waste Management: Fourteen landowners completed feedlot abatement projects using the cost share and low interest loan funds. The feedlot evaluations (FLEVAL) ranged from 25 to 50. Each completed project now has a FLEVAL rating of zero. The average Total Phosphorus reduction per site is 100 pounds per year based runoff evaluations completed on similar projects. Abandoned Manure pits: Two landowners properly abandoned their animal waste storage structure using the MPCA guidelines. Properly closing a storage structure prevents groundwater contamination from leaching nutrients. Abandoned Wells: One landowner properly abandoned an irrigation well using the Minnesota Department of Health guidelines. By properly closing this well groundwater contamination is prevented. 3

5 Minimum Tillage Equipment: One landowner utilized the SRF loan program to purchase a stalk chopper to increase residue cover and to allow for a no-till drill to be used the following spring. The heavy crop residue minimized soil loss during snow melt and increased organic matter in the soil. Shoreland Restoration: Two riparian restoration projects were completed on the Sauk River in conjunction with the Stearns County SWCD. Storm Water: The SRWD worked with the city of Sauk Centre to install a stormwater management project downstream of the Sauk Lake Dam. Seniors and Kindergartners of 2007 helped plant numerous trees at Browns Park to slow the stormwater down and to draw up much of the water before it discharges into the Sauk River. Septic Systems: The SRWD worked with twelve landowners to update their septic systems. Each landowner was given a septic system maintenance guide to help them properly maintain their system. Education Classes and Seminars: In 2006 the SRWD launched the District s Middle School Outdoor Water Quality Education curriculum offering students a hands-on opportunity to collect water samples and conduct analysis, conduct physical riparian assessments, biological assessments and evaluations. SRWD staff attended lake association meetings, school presentations, and conducted shoreland restoration workshops. Community Events: The SRWD staff presented environmental information and education to over 1,000 people/year at community events, 200people/year at lake association meetings, 600 students/year through school activities and maintained an informational booth during the Stearns County Fair each summer. The SRWD also hosted and presented the annual ( ) Middle Sauk River Water Festival. The District also communicated to watershed residents through biannual newsletters and annual reports, newspaper articles and professional journal entries. Monitoring: The purpose of the monitoring program conducted during this implementation project was to track the effectiveness of the watershed-wide land use management improvements and to provide a better understanding of the nonpoint source pollution entering the Sauk River. The middle Sauk River watershed was assessed through a network of tributary monitoring stations and four anchor sites along the river. The District expanded its monitoring efforts to include Lake Sylvia, Little Birch Lake and St. Anna s Lake, which are the headwaters of Adley and Getchell Creek tributaries to the Sauk River. Data was used as part of the Getchell, Unnamed and Stoney Creek TMDL studies. Sample collection and field analysis was conducted by the Sauk River Watershed District with assistance from local volunteers from snow melt through October 1 st. The MNDNR assisted in attaining high flow measurements in 2005 and 2006 and part of The analytical data compiled during this implementation project was compared to data collected during the Diagnostic Study and previous implementation projects to determine year-to-year variability for dry and wet years and corresponding changes in water quality associated with implemented BMPs. The monitoring data indicates that nutrient concentration reductions have occurred in the Sauk River compared to previous diagnostic studies. The latest modeling results show the Sauk River s Total Phosphorus (TP) flow-weighted mean concentration at the Richmond site has decreased between 50-75% depending on wet or dry years. The 1985 MPCA study calculated a TP concentration of 487 ug/l with a flow of 476 cf/s where as the 2005 data indicates a 55% reduction at 206 ug/l with a flow of 486 cf/s. The drier years show a more significant difference. The 1992 Diagnostic Study recorded a mean flow of 242 cf/s with TP concentrations at 571 ug/l. The 2006 model results however determine TP concentration to be 114 ug/l with a flow of 209 cf/s, which is approximately a 70-80% reduction. The TP loading was calculated to determine the differences between wet and dry years. Stream modeling was conducted on the Sauk River at Richmond and for two primary subwatersheds; Getchell Creek and Stoney Creek from The results show that the Sauk River is approaching the Ecoregion average goal of 100ug/L to 150ug/L in Total Phosphorus. However, the Total Suspended Solids concentrations remain percent higher than the Ecoregion average goal during low flows and percent higher during high flow years. 4

6 The Sauk River Watershed District began monitoring the Getchell, Unnamed and Stoney Creek subwatersheds and the Sauk River at the Richmond and Cold Spring sites in By adding anchor sites (SR30 and SR12) along the Sauk River in 2005 the SRWD was able to determine where the largest increase in TP and TSS occurs. The modeling results shows that Getchell Creek and Stoney Creek contribute the largest amount of nutrients to the Sauk River between the Sauk Lake Dam and the Richmond Site on the Sauk River. The Sauk River Watershed District s (SRWD) monitoring data from indicates that improvements have been made since the 1985 and 1993 diagnostic studies however more BMP implementation efforts are needed. To ensure future recreational use for the SRCL system it is necessary to continue water quality management efforts to further reduce current Total Phosphorus and Total Suspended Solids loading throughout the SRCL watershed. The amount of nutrient reduction needed will be determined by the SRCL TMDL Study which is pending MPCA review at the time of this report. 5

7 Project summary The Middle Sauk River project area is located in central Stearns County and southern Todd County (Figure 1). At one time this winding segment of the Sauk River was enjoyed by canoeists and swimmers, but today swimming is no longer desirable and canoeists are few. The increasing rate of riparian development along the Sauk River has prompted concern over the direct, cumulative contributions of on-site septic systems and lawn fertilizers to the water quality of the Sauk River and downstream to the Sauk River Chain of Lakes. In addition, health issues related to non-point source pollutants from farming practices present potential water quality problems in addition to point-source contributions from communities and industries in the watershed. Figure 1 Two studies conducted in 1985 (MPCA s 1985) and 1989 (WRM Inc.1992) identified the Sauk River as the major (89+ %) contributor of phosphorus loading to the Sauk River Chain of Lakes (SRCL), which have been classified as hypereutrophic (over enriched with nutrients). Without corrective actions within the Sauk River Watershed, degradation can be expected to continue which will have negative economic impacts to the local communities, especially the cities of Richmond and Cold Spring which border the north end of the SRCL. Within the Middle Sauk River Watershed lie approximately 1,100 feedlots. This is considered the heart of Stearns County s agricultural industry. For this reason, initiating the Middle Sauk River Rehabilitation Continuation Project is imperative to protect the water quality of the Sauk River, its tributaries and the SRCL. The focus of the Middle Sauk River Rehabilitation Continuation Project was to provide technical and financial assistance in the agricultural community to address the following: Priority feedlots within the watershed, particularly Getchell, Unnamed and Stoney Creeks Work with the agricultural community to address erosion along ditches, creeks and the Sauk River. Address rural septic systems, especially where drain fields are attached to agricultural drain tiles. Work with the agricultural community with land-use BMPs to reduce runoff and protect area surface waters. These efforts coincide with those recommended in the MPCA Limnological Study and the WRM Diagnostic Feasibility Study. The short-term Phase II actions largely focused on stream bank erosion and agricultural concerns within the Middle Sauk River watershed but also continued longer-term education, land use management, septic system upgrading and monitoring efforts. 6

8 Figure 2 Middle Sauk River Rehabilitation Project Objectives Objective 1: Implement an interactive education program for adult and youth within the watershed. Objective 2: Implement a water monitoring program to determine the effectiveness of the BMPs installed during the project and to obtain baseline water quality data for Little Birch, Sylivia and St. Anna s Lake. Objective 3: Install BMPs within the Middle Sauk River watershed and the Getchell, Unnamed, Stony and Adley subwatesheds including feedlot improvements, bank stabilization activities, land retirement programs, buffers strips and urban stormwater abatement. The primary goal for the Middle Sauk Rehabilitation Project Continuation was to prevent further degradation of the Sauk River and the SRCL and to maintain a level where its clean water will serve the needs of future generations. A three year implementation plan was designed to address the Middle Sauk River watershed and associated tributaries with priority given to feedlots and cropland located adjacent to the Sauk River and Getchell, Unnamed, Stoney and Adley Creeks or along drainage ditches and other tributaries that discharge to these creeks. The project objectives are listed above. Completed Priority Management Projects The most effective management options for the Middle Sauk River Rehabilitation Project included working with the County Soil & Water Conservation Districts, Natural Resource Conservation Services, Planning and Zoning departments, township officials and individual property owners to improve land use management in the entire Middle Sauk watershed. Feedlots, erosion, land use BMPs, education and septic systems were the priority issues addressed in this CWP project. The implementation of selected management alternatives completed was done in partnership with the Todd and Stearns County environmental agencies and the individual landowners. Ag Waste Management Efforts were focused on the priority ag-waste sites contributing to the Sauk River using county feedlot inventories. Fourteen landowners completed their feedlot abatement projects within the Middle Sauk River watershed. The average phosphorus reduction per site is 100 pounds per year based on evaluations completed on similar projects. The life expectancy of each project averages about 15 years resulting in approximately 1,500 pounds of phosphorus reduction per site. An added benefit to the overall water quality is the overall manure management. The manure storage facilities changed the landowners manure management methods from daily hauling to spring and fall applications, eliminating winter spreading. Since the manure from the storage facilities is a liquid form the manure is more readily incorporated into the soil, decreasing nutrient runoff. Buffer Strip Program In 2002 the SRWD expanded its buffer strip program by helping to sponsor a full time Pheasants Forever staff member, housed at the Stearns SWCD. The staff biologist s primary responsibility is to promote the CRP buffer strip program focusing on the Sauk River, Stone69*9y, Unnamed, Getchell, and Adley Creeks watersheds. Erosion Control Using the SRF loan program, the SRWD assisted a landowner in purchasing a corn stock chopper head for his combine to increase crop residue. The stalk chopper shredded the corn stalks small enough that the producer could plant through the residue without having to till the soil, as seen in the photo to the right. The residue cover prevents soil loss and helps maintain soil moisture and reduce weed growth, thereby reducing pesticide use. 7

9 Shoreland Restoration Riparian management is an extremely important aspect of any long-term effort to protect the Sauk River and the Chain of Lakes. Implementing shoreland BMPs and providing information and education was a cost effective method to protect surface waters. Two riparian sites within the Middle Sauk River watershed were completed as part of this project. These sites were restored to a more natural state using native vegetation and materials. Funding was a partnership through the Stearns County Soil and Water Conservation District (SWCD), Middle Sauk River Rehabilitation CWP project loan funds and the local landowners. The Stearns County SWCD and Joint Powers (JPA) engineer provided the technical assistance and project inspections. Stormwater: In 2006 the City of Sauk Centre decided to provide a visual reminder to adults and youth in the area, as to the fate of runoff water and the pollution carried with it from lawns, streets, and other impervious surfaces. The City teamed up with the SRWD and the public school to demonstrate how trees and vegetation help slow down stormwater and prevent soil loss. The seniors (class of 2006) and kindergartners of 2006, class of 2018, assisted in the plantings. It is anticipated that by 2018 the trees will have full canopy resulting in minimal stormwater runoff Storm drain to Sauk River Browns Park Stormwater Runoff to Sauk River Seniors Planting Trees Browns Park in Sauk Centre Kindergarteners and Seniors Planting Trees The Sauk River Watershed District Recognition Program The Sauk River Watershed District established an award program in 2003 to honor and thank the residents within the Sauk River Watershed District that put forth efforts to improve our water resources. The SRWD created the R.I.V.E.R. (Residents Improving Valuable Environmental Resources) Award to recognize projects funded through the SRWD incentive program (grant and loans). The SRWD Board of Managers awarded four R.I.V.E.R. awards during this project. 8

10 Septic Systems The Sauk River Watershed District worked with the Todd County and Stearns County Environmental Services (Planning and Zoning) to increase compliance with county ordinances and minimize nutrients to nearby surface waters. The SRWD provided low interest loan dollars to thirteen area residents to upgrade their septic system during this project. Certified county technicians inspected the upgraded systems and each landowner was given a septic system maintenance guide to help them properly maintain their system Information and Education: The SRWD staff was very busy in with its education outreach programs. The SRWD increased its education and outreach program 10-fold during the three years of this project. The SRWD staff presented environmental information and education to community events, lake association meetings, school presentations and a display at the Stearns and Todd County Fairs. News & Information: Press releases and newsworthy information was shared with the local newspapers and annual reports were given out to local officials. Volunteer Training: The SRWD offered two volunteer monitoring training sessions to area volunteers. The training sessions were very well received. Twenty five local residents participated in the Volunteer Monitoring Training course in 2006 held at the city hall in Melrose. Water Festival: To target the youth in the community, the Sauk River Watershed District and its project partners, cities of Melrose and Sauk Centre, hosted the Annual Middle Sauk River Water Festival each year to assist the local schools in educating the area students of the importance of water quality. The Festival was a huge success each year despite the weather. Over 450 students and chaperones from Melrose, Sauk Centre, Grey Eagle, Albany, Freeport and Meire Grove attended this event each year. Months of planning by the Sauk River Watershed District and the cities of Melrose and Sauk Centre took place each year. Twenty-one agency and organization specialists shared their knowledge of our fresh water resources with 4th grade students. Students were thrilled with the hands on activities and the array of information given about water. The SRWD believes that through this method of education, students are able to retain much of what was taught to them. Several photos are shown below showing the different sessions offered. Fisheries Enviroscape Macroinvertebrate Fresh Water Treasure Chests: The Sauk River Watershed District introduced a new educational project in 2004, available to K-12 grade classes within the watershed District titled the Fresh Water Treasure Chests. The program is designed to create awareness about the sensitivity and concern over Minnesota s diminishing fresh water resources and habitat loss in a well stocked treasure chest. Throughout the duration of this project the 6 different treasure chests were used throughout the project area on a monthly basis. 9

11 Environmental Quilt: SRWD staff worked with the Richmond Elementary School 5th grade class to create an Environmental Quilt. The theme for the SRWD s annual Environmental Quilt Program is It is all About Water. The 5 th graders created the quilt patches (8 x 8 ) using this theme. The patches were sewn together by SRWD staff. The quilt was displayed at the SRWD until January 2007 then given to the Richmond Elementary School. River Cleanup: As part of Earth Day the SRWD worked with the Melrose Elementary and High School to clean up the Sauk River at the Melrose City Park. The students gathered several large bags of debris that collected along the Sauk River. Library Board: An interactive display board was set up in area school libraries as part of the SRWD s Traveling Classroom Program throughout the school years. This program reached over 500 students per year in the Middle Sauk River area. The topic for each school year changed to keep the children s attention. The Library Board has been well received based on the surveys we have received from the participating schools. 10

12 Monitoring Summary The purpose of the monitoring plan was to track the effectiveness of the watershed management implementation efforts and to provide a better understanding of the non-point source pollution entering the Sauk River and the SRCL. The monitoring plan covered a three-year period during the open water seasons. The middle Sauk River watershed and the SRCL were assessed through a network of four tributaries, four river sites and six in-lake monitoring stations. The six in-lake sites were selected to represent the SRCL and the flowage patterns, using 3 flowage and 3 non-flowage lakes. These lakes are also referred to as the Study Lakes since they were also part of the MPCA 1985 and 1992 Diagnostic Studies. The SRWD staff conducted field analysis and sample collection every two weeks, and rain events, on the streams sites and in-lake sampling occurred twice a month when possible. Local volunteers from the Sauk River Chain of Lakes Association (SRCLA) assisted the SRWD during lake sampling and conducted Secchi disk monitoring throughout the open-water season. Lake Analysis Summary The Sauk River Chain of Lakes (SRCL) is a reservoir system composed of 14 bay-like lakes with a watershed of approximately 601,920 acres (940.5 square miles). The primary source of water is the Sauk River that enters the chain of lakes from the northwest (near Richmond, Minnesota) and flows in an easterly direction through the system of lakes and ends at the dam near Cold Spring, MN where the flowage is again referred to as the Sauk River. The second water supply source is from the southern part of the watershed, which flows from the Luxemburg Creek watershed, extending from the Eden Valley area and draining into Long Lake on the chain of lakes south end. Figure 3: Sauk River Chain of Lakes Morphological Data PARAMETER UNITS Surface Area 2,456 acres Volume 30,735 acre-feet Littoral Zone 76 % Maximum Depth 79 feet Shoreline Length 75.8 miles Maximum Length 9.4 miles Watershed Area 601,936 acres Lake Elevation feet Mean Depth 12.5 feet Since the Diagnostic study ( ), the amount of annual rainfall has fluctuated from year to year with a range of 10 inches, making it more difficult to determine overall results. As shown in Figure 5, the annual rainfall was significantly higher in 2005 than in 2006 and 2007 which was favorable to the Sauk River Chain of Lakes overall water quality from a runoff standpoint. The 2008 annual precipitation was inches, however the summer months received approximately 2 inches more rainfall than the previous two years. In-lake monitoring occurred in 6 lakes, 3 flowage and 3 non-flowage, consistent with the previous Middle Sauk River implementation and monitoring projects. The lakes were monitored during the open water seasons of The parameters analyzed and the sampling frequencies allowed for the quantification needed for assessments. 11

13 Summer measurements of depth, transparency, temperature, dissolved oxygen, total phosphorus (TP), total suspended solids (TSS ) and chlorophyll A (Chlor- a) were accomplished 6 to10 times per summer at each lake site to facilitate statistical trend detections. Epilimnetic (surface) samples were analyzed from 2-meter composite samples. Hypolimnetic (bottom) samples were collected with a Van Doran sampler approximately 1 meter from the bottom. Samples requiring preservation were preserved in the field and transported to the laboratory on ice. Laboratory analysis was conducted by MDH certified laboratories (RMB and DHIS) under contract with the SRWD. Laboratory results are found in Appendix A. Figures 4 Figure 5 Water quality protection efforts initiated in the previous SRCL watershed management projects appear to have reduced TP and TSS concentrations in the Sauk River and the SRCL. Additional water enhancement projects were completed during the course of this CWP project. However, the monitoring data determined a decline in water quality as shown in the Trophic Status Index values (see Figures 4 and 5). The decline is believed to be associated with the heavy runoff in 2005, especially the flowage lakes, and internal loading in the nonflowage lakes during the back to back dry summers. Horseshoe Lake has been the gauging stick for the SRWD in determining changes in water quality for the SRCL. Although Horseshoe Lake is a deep lake with several bays, the Sauk River runs through the northern portion of the lake. The selected sampling point on Horseshoe Lake is near the center to capture any influence from the river and possible internal loading from the deepest point. The 2006 data shows that Horseshoe Lake reached the short term TP goal of 90 ug/l. However, in 2007 concentrations increased to 133 ug/l, which is believed to be associated with internal loading and lack of precipitation. In 2008 inlake summer average TP concentration for Horseshoe Lake dropped back down to 100 ug/l. This may be due to the additional summer rainfall during July and August. Figure 6 12

14 Lake Modeling: The BATHTUB modeling conducted in 2004 showed significant decline in TP concentrations since the 1992 Diagnostic Study. The 2004 lake modeling results indicate that the TP and Secchi results for the SRCL are following the 1985 predictions rather closely. This reduction should be viewed as a statistically defined change because substantial improvements in water quality have occurred in these lakes from the previously noted problems listed in the MPCA 1985 and 1992 studies. The 2004 modeling results also indicated that additional water quality improvement efforts are needed in order to achieve the TP, transparency and Chlor-a targeted goals established for the SRCL. A Total Maximum Daily Load study was conducted from to determine how much nutrient reduction is needed to improve the water quality of the SRCL enough to meet state water quality standards. The necessary monitoring data, sediment data and diatom information was collected and utilized by Dr. Bill Walker as part of the BATHTUB lake modeling. It is anticipated that the results of this TMDL study will be made available to the general public by the end of this year. At the time of this report, the draft TDML report is pending MPCA review. Stream Analysis Summary: The parameters analyzed and sampling frequencies for the tributaries and the Sauk River were set up to quantify the eutrophication parameters needed for modeling and computing assessments (e.g. FLUX and BATHTUB). Temperature and dissolved oxygen were measured with field equipment (YSI DO and Temp Probe). Total Phosphorus (TP), Ortho Phosphorus (OP), Total Suspended Solids (TSS) and nitrate measurements were completed 8-12 times per site each summer for statistical trend detections. Samples requiring preservation were preserved in the field and transported to the contract laboratory in an ice packed cooler. Laboratory analysis was conducted by MDH certified laboratories (Appendix A) and all data was submitted to the MPCA each year for STORET. Continuous flow data was collected using a CR10 data logger which recorded water elevations every minutes for Getchell, Stoney and Adley Creeks and the four anchor sites on the Sauk River. The three tributaries were gauged 8-10 times per year and attempted to get 60% of these measurements in the high flow season. The MNDNR assisted in attaining high flow measurements in 2005 and 2006 and part of Figure 7 The analytical data compiled during this implementation project was compared to data collected during the Diagnostic Studies (1985 and 1992) to determine year-to-year variability for dry and wet years and corresponding changes in water quality associated with implemented BMPs. Total precipitation data during the Diagnostic Study and this project s time frame was obtained from the Minnesota Climatology website at the Melrose site and was used for comparison purposes. The fourteen year annual average precipitation for was inches and inches for the monitoring months (March-September). The climatology data in Table 1 and Figure 7 indicates that 2006 was the driest year overall. Another interesting point to make is that the total precipitation for the 2006, 2007 and 2008 monitoring seasons fell below the 14 year summer average (21.09) by 2-4 inches. These low water levels made it difficult to conduct stream gauging and to attain 60/40 high flow data. 13

15 During the course of this implementation project, the monitoring seasons range from a relatively wet monitoring season in 2005 to a very dry monitoring season in Nutrient and sediment concentrations generally increase during wet years; therefore, it is important to maintain a monitoring regime in order to measure water quality improvements during wet and dry cycles. The District has maintained a monitoring program since The fluctuating modeling results for these years are shown in the graphics below for Getchell Creek and Stoney Creek. Note the differences in annual mean flow as it correlates to rise and fall in TP and TSS concentrations and annual loading. Table 1 Annual Precipitation Data from the Melrose/New Munich Area Middle Sauk River Region Annual Precipitation Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total Precip Average Modeling Results: The SRWD conducted a four year monitoring program from on the four primary tributaries to the Sauk River, Getchell Creek, Unnamed Creek, Stoney Creek and Adley Creek. FLUX Modeling was conducted on these creeks to determine their annual flow weighted mean concentrations and annual loading to the Sauk River. Stream nutrient loading was derived from stream-discharge (flow) and nutrient concentration data collected at gauged monitoring sites located on each tributary. Data from these sites were compiled for a period extending from , with chemistry data from March through September. Stream-load estimates and flow weighted mean concentrations for each monitoring site were generated through the use of the FLUX modeling program. Modeling was conducted on each site for years However, the District was unable to conduct a FLUX model on Unnamed Creek due to the lack of available equipment (data logger) for years 2005 and The yearly FLUX results are described below and can be found in Appendix C. Streams Data Analysis Summary: The primary goals of this Phase II watershed management effort was to reduce the TP, and TSS concentrations for the Sauk River, and its tributaries, to ecoregion target goals of ug/l of TP and TSS to < 20mg/L as shown in Table 2. The main focus areas have been the Sauk River and the Stoney, Unnamed and Getchell Creek subwatersheds since they were identified as significant contributors of phosphorus into the Sauk River. 14

16 Table 2 North Central Hardwood Forest Stream Ecoregion Data (MPCA) Field ph TSS (in mg/l) NOX (in mg/l) TP (in ug/l) Turb (in NTU) FC (in # of organisms per 100 ml) Temp (degrees C) BOD (in mg/l) Sauk River at Richmond and Cold Spring: The Richmond site on the Sauk River was established in 1994 as the checkpoint to gauge what is happening within the upper watershed and to determine nutrient loading to the SRCL. The Cold Spring site is used to determine nutrient concentration leaving the chain of lakes system. Electronic data loggers were installed on the Sauk River at these two sites to collect continuous water level data throughout the year. Using a DNR established stage-todischarge rating curve, water levels were converted to flow measurements. This information was used to create the hydrographs shown in Figure 8. Richmond Site on Sauk River Figure 8 Stream modeling was conducted by SRWD staff for several monitoring seasons to determine water quality trends and year to year variability. The modeling results indicate that the TP flow weighted mean concentrations correspond to runoff and annual precipitation rather closely. Based on the graph shown in Figure 9, the Sauk River, at Richmond, achieved ecoregion average TP concentrations when the mean annual flow was 250cf/s or less. 15

17 Figure 9 Recent Flux modeling results were compared to the 1983 and 1992 diagnostic study results as a method of determining water quality improvements (see below). The 2004 and 2007 monitoring seasons recorded average annual precipitation similar to the 1989 monitoring season (1992 Diagnostic Study). In 2004 the Richmond site recorded a TP flow weighted mean concentration of ug/l, with an annual loading of 52,718 pounds, compared to the 1992 Diagnostic Study of 571 ug/l, or 281,442 pounds. The 2007 results noted a slightly wetter year; however, a 60% decrease in TP was recorded. During the significantly wetter years, the 2005 modeling results show a significant reduction in TP loading. The 1985 MPCA study reported 1983 as a wet year resulting in a TP loading of 347,000 pounds. The 2002 and 2005 seasons recorded even higher mean flows however the model data resulted in 186,676 pounds and 196,683 pounds respectfully. Although it appears that the Sauk River (Richmond site) is approaching the targeted ecoregion TP concentration goal ( ug/l), the TMDL study results will determine how much additional TP reduction is needed in order for the SRCL to achieve the required water quality standards. Figure 10 Sauk River at Richmond Total Phosphorus Load Comparison of High and Average Flow Years 1983 total phosphorus load = 347,000 pounds (wet year, 425 Hm3) vs total phosphorus load = 186,676 pounds (wet year, 439 Hm3) 2005 total phosphorus load = 196,683 pounds (wet year, 434 Hm3) 1989 total phosphorus load = 281,442 pounds (average year, 223 Hm3) vs total phosphorus load = 52,718 pounds (average year, 209 Hm3) 2007 total phosphorus load = 111,343 pounds (average year, 277 Hm3 Table 3 Sauk River at Richmond and Cold Spring Total Phosphorus Modeling Summary Site Name Year CV Total P FWM (ug/l) Mean Flow Hm3/Yr Mean Flow (CF/S) Load P (kg/yr) Load P (lb/yr) RICH , ,427.8 RICH , ,676.0 RICH , ,656.2 RICH , ,718.9 RICH , , RICH , , RICH , , COLD , ,251.0 COLD , ,877.9 COLD , ,597.6 COLD , ,100.7 COLD , , COLD , , COLD , ,

18 The Sauk River, at its outlets of the SRCL in Cold Spring, shows a correlating reduction in TP (see Figure 13). The MPCA 1985 report recorded an annual TP load on the Sauk River at Cold Spring of 270,657 pounds in 1983 where as the 2002 modeling results show a 35% reduction in loading at 175,878 pounds with the 2005 results showing a 51% reduction in TP loading. An 85+% reduction in TP leaving the Sauk River Chain of Lakes was recorded in 2004 at 35,107 pounds compared to the 315,280 pounds documented in The 2007 modeling results showed a 72% reduction versus the 1989 data, even though the mean annual flow was 23% higher. The MPCA s Sauk River Chain of Lakes 2004 Progress Update Report states that the past two decades of watershed phosphorus management has made measurable and statistically significant improvements in water quality. The TP loading over this time frame resulted from improvements to a combination of municipal wastewater (majority of the reductions), municipal stormwater, shoreland and agricultural sources. Figure 11 Modeling for sediment concentrations began at the two Sauk River sites in 2001, as shown in Table 4. Results show that since 2001 a reduction in TSS flow weighted mean concentrations has occurred at both the Richmond and Cold Spring sites. However, concentrations are still 30-40% higher than the ecoregion average and the targeted goal of 10,000-16,000ug/L. The sediment loading from the Sauk River negatively impacts the water quality of the Chain of Lakes and the aquatic habitat within them. Table 4 Sauk River at Richmond and Cold Spring Total Suspended Solids Modeling Summary Site Name Year CV TSS (ug/l) Mean Flow Hm3/Yr Mean Flow (CF/S) Load TSS (kg/yr) Load TSS (lb/yr) RICH , ,638, ,457,914.6 RICH , ,947, ,804,700.6 RICH , ,581, ,512,974.8 RICH , ,871, ,150,925.4 RICH , ,880, ,196,458.4 RICH , ,720, ,408,213.0 RICH , ,139, ,536,750.8 COLD , ,295, ,085, COLD , ,769, ,025, COLD , ,346, ,994, COLD , ,342, ,371, COLD , ,558, ,871,508.0 COLD , ,674, ,306,424.0 COLD , ,080, ,203,504.0 In 2004 two anchor sites were installed on the Sauk River in the center part of the region. The 2005 monitoring season was the first full year of data. These two anchor sites provide a more investigative approach to narrowing in on the concentration changes up and down the middle Sauk River region. The 2005 data helped the SRWD determine which tributary contributed the most nutrient loading to the Sauk River. The chemistry data indicated that a significant spike in TP and TSS concentrations on the Sauk River occurs between County Road 31 (SR31) and County Road 12 (SR12). The new 17

19 information attained will be used to determine where further implementation efforts are needed within the Sauk River watershed and provide statistical concentration changes from year to year. Getchell Creek, Unnamed Creek, Stoney Creek and Adley Creek: Getchell Creek, Unnamed Creek, Stoney Creek and Adley Creek are located in central Stearns County in the Middle Sauk River region and in the North Central Hardwood Forest Ecoregion. The primary land use within these subwatersheds is row crop agriculture and there are approximately 1,600 feedlots. Monitoring has occurred on these creek sites for over a decade on Getchell Creek and Stoney Creek. Unnamed Creek and Adley Creek have 3-5 years of data. Unnamed Creek was removed from the monitoring program in 2002 due to the significant site alterations that took place when the bridge was reinforced with rip rap. Sampling resumed in For this implementation project monitoring data was collected from snow melt 2005 through September The 2008 data was not used as part of this analysis due to lack of summer data. The long term TP and TSS concentration goals set for these sub-watersheds is to attain the ecoregion flow weighted mean concentration averages of ug/L for TP and 10,000-16,000ug/L (10-16mg/L) for TSS. Table 5 Getchell Creek Flux Modeling Results Year FLOW (cf/s) (Open water season) TP Conc. (ug/l) TP Loading (lb/yr) TP lbs/acre TSS Conc. (ug/l) TSS Loading (lb/yr) TSS lbs/acre , , , ,511 1,540, , ,760 4,038, , ,273 11,651, , ,907 1,541, , ,495 4,737, , ,511 3,281, , , , , ,526 1,245, , , , , , , Getchell Creek: Getchell Creek s watershed is approximately 42,616 acres (66.6 sq. miles) and predominantly consists of agriculture land uses. Getchell Creek flows along the eastern edge of the city of Freeport. The semi-annual waste water from this community is discharged into Getchell Creek in the spring and the fall. The discharge data for the City of Freeport is on file at the Minnesota Pollution Control Agency. The modeling results for Getchell Creek shows a strong correlation between annual loading and annual precipitation. As shown in Table 5, the TP and TSS loading patterns the rise and fall of the mean annual flow. However, the TP flow weighted mean concentrations do not reflect the same correlation, as shown in Figure 10. This may be due to an influence by the Freeport municipal waste water discharge and minimal dilution during the dryer years. The 1982 MPCA report states that Getchell Creek s TP discharge was approximately.65 lbs/acres. More current data shows a significant decline in 2004 at 0.11 lbs/acre and 0.36 lbs/acre in An important point to consider is when precipitation is received and at what duration. If the majority and heaviest rainfall events occur prior to crop cover, or after harvest, there is a tendency for higher concentrations. Recent modeling data also shows significant fluctuation in TSS concentrations. The TSS concentrations show a decline since the late 1990 s, even during the wet years. TSS flow weighted mean concentrations appear to be approaching ecoregion target goals of 10,000-16,000ug/L (Figure 11). The 2004 modeling results determined that under near average rainfall conditions Getchell Creek s TP and TSS concentrations maintained within the targeted goals with 186 ug/l of TP and TSS at 10,367 ug/l. Therefore to achieve nutrient concentration goals during wetter years additional watershed management efforts are needed. 18

20 Figure 12 Unnamed Creek: Unnamed Creek s watershed is approximately 10,880 acres (16.99 sq. miles). The watershed land use consists predominantly of agriculture with rolling topography. The steeper slopes increase runoff rates affecting water quality and quantity (volume and velocity). The 1982 MPCA report states that Unnamed Creek s TP discharge was approximately.94 lbs/acres. The SRWD s 1997 data showed a significant decrease at.178 lbs/acre, whereas the 2002 modeling data showed a lesser decrease of.501 lbs/acre. This can be linked to the increased runoff due to the above average rainfall in Stream modeling has not been conducted on Unnamed Creek since 2002 due to changes in site conditions. Therefore, to determine any water quality changes since 2002 the 2008 mean summer average was compared to the summer average data. With the exception of the 2000 drought year, Unnamed Creek s summer average TP concentrations have maintained above the Ecoregion average by approximately 50% based on the available summer average data (Figure 11). Figure 13 19