OTTERBEIN LAKE PROJECT: WHAT WE HAVE LEARNED SO FAR

In June 2008 Otterbein University (OU) began an effort to assess the hydraulic characteristics of Otterbein Lake. At the 2008 GSA meeting Svitana, Prose and Downs presented a poster which highlighted cooperative effort between the City of Westerville, Ohio the Otterbein Lake Project citizens group and OU. This publication “Otterbein Lake: an example of public/private partnership, community engagement and science” describes the effort to reclaim the lake and incorporate the area into the city’s existing park and recreation infrastructure. A goal of the lake’s revitalization is gathering scientific data from the area and incorporating the information into the city’s public information and awareness program regarding its natural areas and resources. The environmental assessment focuses on the hydrologic connections between the lake and the adjacent stream, Alum Creek. A summary of the findings to date are:

• A unique hydrogeologic condition exists. A low head dam on the creek causes groundwater recharge along the west side of the lake and an excavation for a sanitary sewer line along the eastern side of the lake causes leaky discharge. It’s estimated this condition causes water in the lake to replenish frequently.
• Water quality analysis shows a consistent relation between Alum Creek’s base flow water qualities and the Lake’s water quality.
• Fe, Mn, Na, Ca, sulfate, chlorides and turbidity have increased concentrations during rainfall events that are likely attributed to sediment incursions from runoff.
• Groundwater fluctuates when controlled releases from the US Army Corps of Engineers flood control dam (Alum Creek Reservoir) occur. The reservoir is situated 6 miles upstream from the Otterbein Lake area. These releases are important to city’s ability to meet water supply demand from Alum Creek.
• The city operates a groundwater extraction well field to augment surface water, the well field is one quarter mile north of the lake. Extended groundwater pumping by the city during the first half of 2010 had no apparent impact on the stream levels or the groundwater levels around Otterbein Lake.

Assessment of the water resources related to Otterbein Lake and Alum Creek are ongoing. The intent of this program is to continue these studies to create a multi-generational database to be used in the OU Earth Science curriculum.