We plan to plant blueberries at the low end of the pond where the overflow is located. I have dug small swales along which we will plant the berries. The theory is that the overflow in winter/spring will keep this area moist which blueberries like. During summer I can flood the swales from time to time to effectively keep this area moist. The soil pH was about 5.5. I applied some sulphate of amonia to further lower the pH. The berries will be planted in holes filled with half compost and peat moss.