i've been spending a great deal of time mapping the storm drains around my area (north of San Diego). does anyone else do this or is it just me? i'd love to hear from fellow explorers who map underground!
all my maps are done on google earth - i take notes underground about the features which would be visible from the surface (manholes, gutters etc.), their distances and approximate angles, and then trace the paths on google earth. i'll include some pics below, but since i'm not a full member i don't want to post actual locations .. so for the close-up maps i've covered the satellite image with white.
here's a close-up map of a couple different tunnel systems. the one on the bottom is approximately 1.02 miles long, the ones on top are even longer (and more branchy). dark blue lines are underground tunnel, light blue is open creeks and streams.
"G+M" = gutter + manhole. markers are junction boxes which i've been inside (numbering is so i can refer to each one uniquely). green pushpins are inlets/outfalls or other points of entry. purple pushpins are pipes that continue which i haven't mapped yet.
(and yes, i'm aware i could probably get the city maps for my area, but that would take the fun out of it, plus city maps are not always very accurate).