Posted by Floodway ...the only problem I have with the one here is that it doesn't really specify drain sizes, so it's hard to tell which ones are actually explor-able and which are too small to consider. |
I enjoy the hunt. Finding 10 small drains in a row makes the next big one or the more rewarding.
Also, to some extent you can increase your odds - usually longer systems with lots of tributaries would be bigger downstream.
I also look for sections where the tunnel opens up again back into a waterway (so you have an inlet & an outlet rather than the tunnel just shrinking) as sometimes, even if they're not that long, they may be bigger or have a good feature. If they're part of a bigger river, all the better - they may have only put it underground for a bit while it runs under a shopping center or a freeway.
Even a percentage of the 5ft or smaller drains could have an old bigger section. I used to always check smaller drains that went under railway lines as they'd often have bigger older sections there.
Anyway, definitely not meaning to talk down to anyone - I just spewing out my thoughts.
Cheers