Zerkalo, I might be missing something here, but looking at the map, it seems that you have to drive down a lane that runs alongside the canal. This looks like the entrance to the fishery. There appears to be a towpath, in use by cyclists in one of the pictures, and several places that you could park. so there must be some public access. With all this in mind, how could you get 'locked in'? It looks like the gate is only meant to keep people out of bit with the lakes.
★★★★★ · Fishing pond · Prestwood Dr
www.google.com
It does look an interesting place though, especially the wider parts as it heads towards the town.
John.