Making the Connection

For the past week or so the news has been a buzz with stories about Lake Champlain reaching record high water levels.  Roads are closed, schools have shut down, and homes have flooded.  Running in the uplands of Worcester I find myself far removed from this reality but I can't help but wonder what factors lead to the Lake reaching such high levels.  Firstly I considered the weather patterns of the past few months.  We certainly got a lot of late snow this year and have had a pretty rainy spring.  But we've seen patterns like this before and not had much of a problem so I put some more thought into it.  It wasn't long before I considered a more likely culprit: impervious runoff.

It may seem like a small contributor to the problem but it's much larger than you think.  Impervious cover comprises a large percentage of the Lake Champlain Watershed.  Every road, parking lot, and roof is included in this number and each adds cumulatively to the total amount of water draining to the Lake.  As opposed to pervious cover such as lawns, grasslands, and forests which provide water an opportunity to filter into the ground and be absorbed by the soil and taken up by plants, impervious cover simply provides a surface on which water can move.  And in many cases, this surface moves water straight into a stormdrain and then directly into nearby streams via a pipe or culvert.  It's no wonder why the lake is so high.  We are essentially capturing stormwater and funneling it right to the Lake.

Luckily, there are some folks trying to deal with this exact problem.  Many municipalities have enacted regulations which ensure that new developments mitigate impervious cover.  A few organizations, such as WNRCD and Friends of the Winooski River, have been promoting rain barrels and rain gardens.  Even the State of Vermont has provided some guidance on low impact development practices that can be used to mitigate stormwater.  I guess we just have to hope that these actions haven't come too late.  As we've found with phosphorous in the Lake, maintaining current levels is difficult enough.  Bringing those levels down is near impossible.