jnaus1,
You may want to try a fish tape (stiff metal wire on a wind up reel)electricians use them usually can borrow one. Anyway you would push this in till it stops, push it back and forth and have someone else walk around and listen for probably a tapping sound which would be a burried vault that your valves are in. If this works you would use this fish tape to pull the controller wire back in that conduit.