Large Scale Lake Planning
Mary Lake is a small (156 acres) natural drainage lake (Mary Creek inlet and outlet) located on the border between Langlade and Oconto Counties, Wisconsin. Existing excellent water quality is attributable to spring inputs (to Mary Creek and Lake) and an undisturbed forested watershed almost completely within the Nicolet National Forest. Nutrient levels are at or below those typical for the ecoregion (which are low compared to other regions); nutrient inflow to the system from the extended or immediately adjacent watershed does not appear to be significant. Transparency is such that light is able to penetrate to the entire lake bottom most of the time. Trophic State Index ratings typified oligotrophic to early mesotrophic conditions. Lake level, a major concern of Mary Lake riparian landowners, is controlled by a series of beaver dams on the outlet stream. Water levels for the period 1989 - 1992 varied almost two feet; this variability is aesthetically, and probably ecologically, significant given an average lake depth of only five feet. Levels appeared to drop significantly when natural or human activities affected the dams. Levels did not exceed the Ordinary High Water Mark, but fell below the recommended minimum level (available staff gage readings) several times during the period. Recreational use of Mary Lake is reported to be light. The lake receives most use during Summer months, mainly in non-consumptive activities such as viewing nature, wildlife watching, fishing and swimming/sunbathing. More aggressive activities such as water and jet skiing and sailing were less popular. Riparian sanitary systems were reported to be adequately maintained. Onsite water sampling near suspected failing systems suggested that the systems were operating adequately. Management objectives and recommendations were designed to increase the knowledge of Mary Lake, track trends and control lake levels: *Riparian landowner education and awareness regarding yard practices should be emphasized and measures implemented where appropriate and practical. * Water quality monitoring should be continued to supplement the relatively small amount of information available. Secchi depth monitoring should be continued along with lake level readings. Rainfall data should be recorded as practical to supplement this data. Event testing of areas of concern may be implemented. * Efforts should be made to verify the level of the current gage. Also, reassessment of the Ordinary High Water Mark ( OHWM) and the recommended minimum level for the Mary Lake resource seems necessary. Lake level fluctuation, which can reduce spawning success, cause flooding and disrupt plant growth in and around the lake should be controlled. Installation of a beaver pipe may help to alleviate this problem. * Public access to the lake may be improved, particularly since public access via the private ramp has been discontinued. A ramp on the north shore of the lake was installed years ago but has since deteriorated.
Establish a planning advisory committee to finalize goals and objectives. Review existing information. Prepare base maps of the lake and its watershed. Conduct lake monitoring program. Record lake levels and determine downstream gradient and flow regime. Assessment of opportunities for public access to be conducted. Public information dissemination. Comprehensive lake management plan will be prepared.
Lake Management Plan Development
Watershed Mapping or Assessment
Monitor Water Quality or Sediment
Comprehensive Planning Studies
Monitor Water Level