As you walk out of the car park there is a map of the area - I suggest you take a quick photo of this!  Follow the path uphill.

At the 1st junction you can go straight on up the rockier and steeper path (I usually go up this way and return on the gradual path). Or you can turn right and follow the gentler gradient route which rejoins the direct path further up. If you choose the "rocky route" ignore the bridge over the stream and continue uphill with the stream on your left.

You'll meet the "gentle route" coming in on your right when the path begins to flatten out. When the path forks, follow the main path to the left, which will bring you to a lovely bench near a ford and bridge. Ignore the bridge and follow the path on the right to the Low Dam. The top of Low Dam is very shallow and ideal for dogs and children to play in the water.

If you continue uphill a short walk will bring you to High Dam itself. You can follow the circular path around High Dam in either direction. I like to cross the bridge to the right and follow the main path anti-clockwise. There are mini bays on the left where you can enter the water and paddle/swim. 

Bear left, ignoring the gate ahead and cross the boardwalk for a climb up to the bench for a great view. The path drops down through the woods and you see High Dam again on your left. As you get closer to the dam wall there is a path junction.

I like to turn right here and the path goes through the woods to the ford/bridge/bench below Low Dam. If you choose the left path you'll walk along the dam wall and turn right before crossing the bridge. This will then lead you back past Low Dam to the bench.

On the return route I bear left and follow the more obvious and gentle descent that I didn't use on the way uphill. The car park is visible on your left from this path.