Sunday, May 25, 2014

Alum Creek Beach

We spent last weekend outside of Columbus, Ohio, watching a national collegiate Ultimate tournament.  The event was held in Westerville, in the floodplain of Alum Creek, which flows through the northern and eastern suburbs of Columbus before joining Big Walnut Creek and then the Scioto River, south of the city.

Alum Creek Dam was three miles upstream of the tournament and in a brief break between games, on a quick trip primarily to buy coffee and to top off the tank of the rental car, I swung by the only nearby beach my pre-trip reconnaissance had found. I had about five minutes on site.


Reservoirs can be neat exhibits of beach behavior under changing water levels -- at least where lake level intersects a gradually sloping surface with abundant sand and gravel. Rising water levels can push berms and barrier beaches upslope. Falling water levels can leave a series of regressive beach ridges and stranded spits.

As best as I can tell from some quick searches, the reservoir is pretty much at its normal summer level. From the photos, it appears that the water has been slightly higher this season, but not more than a few inches.  I have no idea whether the stranded berm is the result of higher water over a period of weeks, or whether it's simply the result of rainfall, wind set up, and waves during the heavy squalls that came through the previous afternoon.

This long artificial beach is broken by numerous small runoff channels, spaced roughly 100' apart (zoom in on Google Earth image). They may reflect drainage points in the sidewalk that marks the back of the beach or they may just represent the break between sheet flow and channelized flow on this particular man made landscape.  Regardless, each ends in a small lagoon and inlet at the lake's edge, resulting in a series of several dozen fairly similar micro-estuaries and regressive spit complexes.

For other reservoir beaches from unlikely locations:
Lake DeSmet, Wyoming 2013
Lake Mead, Nevada 2009

And for another artificial beach in Ohio, see Maumee Bay 2010.