This scenic, 2 mile long reservoir is surrounded by steep hills, thick uplands forestry and in the valley, lush green fields and farmland. There are forest walks in the higher ground above the reservoir which will give you some good views of the valley.
In my own case I walked around the reservoir more or less at the same level as the reservoir itself.
If you are going around it anti-clockwise from the dam, you will first go through scenic forestry paths with views of the Reservoir to your right. There is not too much hillwork involved though the path is undulating. On the return half of the journey, having passed through some farm property and over a wooden bridge at the far end, you head through farm fields.