Mike, I had something happen similar last year, in April. Right before my pond filled up. It turned out to just be a week or so of worry as it washed out or went away on it's own. Here is a short thread with photos for comparison...

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Main=35937&Number=470475#Post470475

The pond tried to do something this year to a much lesser extent about the same time, but dissipated...it's amazing what you can notice when you tend to a pond on a daily basis, or should I say it's amazing what you miss when you don't.


Fish on!,
Noel