Sign in the log book in the office first, then drive slowly through the maintenance buildings to the north of the office to the back gates to access the ponds. 

Often the gates aren't open yet at 8 am when access is allowed so you have to find someone and ask them nicely to open them for you and they are always very nice. They do like people to clear out by around 2:45 however so they can get ready to shut things down.