I also installed a dry hydrant at the urging of the local fire chief. Their trucks only hold 1000 gallons and I understand that is pretty standard for fire trucks. He told me the 1000 gallons won't put out a camp fire, so if you value your home, better put one in. I had to make sure the fittings were consistent with the townships machinery, and the end in the pond had to be screened to prevent stuff from getting in. Ironically, the 1000 gallons isn't used for the fire, they back flush the hydrant with this water to blow any growth on the screen off, before they draw the water off for use. The only problems I've had so far is the hydrant is about 30 feet higher than the pond. It takes all the power the truck has to draw it up the 30 feet. If you have any pressure head to deal with, be forewarned.
When I put the hydrant in, I contacted my house insurance company and my premium went down about $200.
