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averaged 3.3 feet between 1995 and 2000 (ran�c of 2.2 feet to 4.4 feet). Further, the 197f <br />environrriental assessment for thc Hyman Frei�htway truck terntinal {p�, b of report} suggested <br />that the water quality of Langton Lake was "very close to the analysis oF roadway runoff'. This <br />is clearly not the case now and suggests that water yuality in Langton Lake may have improved <br />significantly fxom the 1970's and early 1980's. <br />With t�e help of volunteer Dr. Jerry Beilby, a Langton Lake watershed resident and long-time <br />user oF the Park, monitozing of water levels in the middle cell in response to rainfall events <br />between July and September 2001 was carried out. This type of data can be of help in assessing <br />the suitability of a wetland or lake to support a stable emergent community along the ed�e of the <br />water. Development of a stable, diverse eznergent community is an important component of a <br />healthy wetland/lake system. The data collected by Dr. Beilby is pz'esented in Appendix A. <br />Among the findings are that the watcr �evel "bounce" in Langton Pond was just over 6 inches (.5 <br />feet) for a 2.5 inch, 24 hour rainfall (about a"1-year" rainfall). Further, it took several weeks for <br />the water level to return to near the pre-event elevation (only one minor rainfall event was <br />recorded during this period). Thus, the magnitude of the water level fluctuation in Langton Lake <br />is moderate whiie the duration of the high water level is fairly long. For the most part, the <br />systern has sustained a modez'ately diverse and extensive emergent frin�e, but greventina <br />increases in both the bounce mab itude and duration will be important to protect the existing <br />system. This means that expansions in the size of the watez'shed and in the impervious coverage <br />(at least wilhout extensive flow rate control} should be avoided. <br />Aquatac Vegetation Survey <br />As part of the ficld survey for Langton Lake conducted during this project, qualitative <br />observations of submergent and emergent aquatic vegetation were made durin� field visits in <br />June, July, and August 2001. The ve�etation survey was carried out with two primar� objectives <br />in mid: <br />1. To determine to what extent, if any, there are infestations of exotic species. <br />2. To determine the diversity of nativc spccies in the lake. <br />City of Roseville 41 <br />Paiks Natural Resource Mayiagemefat <br />