We’ve had some unseasonably warm weather here in southern NY this year – so warm that the ground hadn’t frozen by the New Year, allowing me to build earthworks into the beginning of winter. My latest project is to put a small water catchment swale and berm in my front yard.

The idea behind a swale and berm is actually pretty simple. You start by establishing a series of points of common elevation – a contour line. Then, dig a ditch of consistent depth that connects those points (the swale) and pile the soil on the downhill side to form a long mound of consistent height (the berm). When it rains, instead of water running off the land it flows into the swale. Since the swale is a constant elevation, the water sits there and slowly seeps into the bottom of the swale and the berm.

The benefits of this setup are mainly twofold. First, if you use the berm as a planting bed – with the surface adequately mulched – you don’t need to worry about watering. Second, runoff will slowly accumulate rich silt in the moist bottom of the swale, encouraging the growth of moisture-loving plants.