Oliver, Olin, and Martin Lakes Diagnostic Study Lagrange County, Indiana
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Oliver, Olin, and Martin Lakes Diagnostic Study LaGrange County, Indiana October 16, 2009 Prepared for: Oliver and Martin Lakes Conservation and Improvement Association c/o Lynn Bowen 1155 E 455 S LaGrange, IN 46761 Prepared by: 708 Roosevelt Road Walkerton, Indiana 46574 (574) 586-3400 OLIVER, OLIN, AND MARTIN LAKES DIAGNOSTIC STUDY LAGRANGE COUNTY INDIANA EXECUTIVE SUMMARY Oliver, Olin, and Martin lakes are 391.9-acre, 101.4-acre, and 25.6-acre (158.6-ha, 41-ha, and 10.4-ha), natural lakes that lie in the southeast portion of LaGrange County, Indiana within the Oliver Lake-Little Elkhart Creek watershed (HUC 040500011506). Together, the lakes create the Oliver, Olin, and Martin (OOM) lakes watershed, which stretches out to the north and east of the lakes, encompassing approximately 6,856 acres (2,774.6 ha or 10.7 square miles). Water flows from Martin Lake to Olin Lake and into Oliver Lake before discharging out of Oliver Lake’s outlet in the southwest corner. Most of the OOM lakes watershed (~64%) is utilized for row- crop agricultural while approximately 16% of the watershed is utilized for hay or pasture. The remaining 20% of the watershed is divided among remnants of natural landscapes (~7%) composed of wetlands and forested areas, and residential and commercial developments (~4%). Open water including Oliver, Olin, and Martin lakes covers approximately 7% of the entire watershed. Water quality parameters and biotic metrics were assessed at four stream locations throughout the watershed. In general, the biological condition of the streams in the OOM lakes watershed is poor with the macroinvertebrate community being classified either “Impaired” or “Slightly Impaired” and the stream habitat being classified in the three of the four sites as “Non- supporting of aquatic life”. Turbidity, stream temperature, and total suspended solids measured during the study were within normal levels for northern Indiana streams and not at levels that would significantly affect aquatic organisms. Nutrient levels such as nitrogen-nitrate, nitrogen- ammonia, and total phosphorus were, in general, elevated during storm flows. Dove Creek in the Oliver Lake watershed and an unnamed tributary in the Martin Lake watershed contribute the highest amounts of sediment and nutrient loading to the lakes. E.coli levels were at or above Indiana state standards a minimum of once during the sampling period at each of the four stream sampling sites. Oliver, Olin, and Martin lakes contain good water quality. Historical data for the lakes suggest that water quality has remained relatively stable over the past 30 years. The lakes possess generally better water clarity and lower nutrient levels than most Indiana lakes. Evaluating the lakes using various trophic state indices suggest the lakes are primarily mesotrophic in nature. Internal loading of phosphorus through its release from the sediments in Oliver and Olin lakes represents a potential for each lake to increase the productivity over time. During the summer aquatic vegetation assessment, northeastern bladderwort, a species thought to be extirpated from Indiana, was observed. Continued good water quality in Oliver, Olin, and Martin lakes will require both in-lake and watershed management. Oliver and Olin lakes possess hydraulic residence times of 1.9 and 1.1 years, respectively, while Martin Lake has a hydraulic residence time of 0.3 years. Attention to watershed and near shore practices prior to addressing in-lake processes is necessary. Stream sampling and phosphorus modeling indicate the row-crop agriculture within the each lake’s watershed contributes the largest single external source of phosphorus. Good watershed management is necessary to protect the OOM lakes’ water quality. Recommended watershed management techniques include: replacement or repair of several failed existing sediment control structures and grassed waterways, stream and drainage stabilization, wetland restoration, stormwater filtration, and agricultural best management File #070874.00 Page i Oliver, Olin and Martin lakes Diagnostic Study October 16, 2009 LaGrange County, Indiana practices (BMPs). Within the lakes themselves, stakeholders are encouraged to develop an aquatic plant management plan to provide a framework to manage invasive exotic species present in the lake and protect the native plant community. Also, the implementation of BMPs such as using Phosphorus free fertilizers, not mowing lawns to the waterline, utilizing rain gardens or rain barrels for increased water detention and naturalizing existing concrete seawalls are recommended to lake residents. ACKNOWLEDGMENTS The Oliver, Olin and Martin lakes Diagnostic Study was made possible with funding from the Indiana Department of Natural Resources (IDNR) Division of Fish and Wildlife, Lake and River Enhancement Program (LARE), and the Oliver and Martin Lakes Conservation and Improvement Association (OMLCIA). The Oliver, Olin, and Martin lakes Diagnostic Study was completed by JFNew and their subcontractor, Indiana University School of Public and Environmental Affairs. Contributors to this study included the IDNR Division of Division of Fish and Wildlife and the IDNR Division of Nature Preserves. Special thanks to the dedicated members of the OMLCIA for their initiative and assistance in getting this study completed. OMLCIA members who participated in the study included: Lynn Bowen, who served as the primary liaison between JFNew and the OMLCIA; provided JFNew with directions and information during the watershed tour; Fred Leiter who navigated us around the lake during the rooted plant survey; Buck Toenges, who provided useful historical fishery information. Authors of this report included William Jones and Thomas Parr at Indiana University. The primary author at JFNew was Mark Pranckus with contributions from Betsy Ewoldt, Karen Quinlan, Holly Jones, Sara Peel, Tom Estrem, and John Richardson. File #070874.00 Page ii Oliver, Olin and Martin lakes Diagnostic Study October 16, 2009 LaGrange County, Indiana TABLE OF CONTENTS PAGE 1.0 Introduction ............................................................................................................................. 1 2.0 Watershed Characteristics ...................................................................................................... 4 2.1 Topography and Physical Setting ........................................................................................... 4 2.2 Climate .................................................................................................................................. 10 2.3 Geology ................................................................................................................................. 11 2.4 Soils ...................................................................................................................................... 12 2.5 Natural History ...................................................................................................................... 19 2.6 Land Use ............................................................................................................................... 20 2.7 Wetlands ............................................................................................................................... 23 2.8 Natural Communities and Endangered, Threatened, and Rare Species .............................. 27 2.9 Prior Studies ......................................................................................................................... 29 3.0 Stream Assessment .............................................................................................................. 30 3.1 Stream Assessment Introduction .......................................................................................... 30 3.2 Stream Assessment Methods ............................................................................................... 32 3.3 Stream Assessment Results and Discussion ....................................................................... 39 4.0 Lake Assessment .................................................................................................................. 57 4.1 Morphology ........................................................................................................................... 57 4.2 Shoreline Development ......................................................................................................... 63 4.3 Historical Water Quality ........................................................................................................ 66 4.4 Lake Water Quality Assessment ........................................................................................... 83 4.5 Macrophyte Inventory ......................................................................................................... 105 4.6 Fisheries ............................................................................................................................. 129 4.7 Lake Use ............................................................................................................................ 131 5.0 Modeling ............................................................................................................................. 132 5.1 Water Budget ...................................................................................................................... 132 5.2 Phosphorus Budget ...........................................................................................................