Alaska is not a good storm draining environment: small towns mean small drains, and LOTS of rain, especially in the "panhandle" of Southeast Alaska, means few chances to safely explore. Here are a few drains that have been located so far:
Big drain found on April 1st (wink wink)
Other Info and misclaneous pictures:
This tunnel is only 4ft wide, and half flooded.
Sitka's very own polluted death swamp