DIY mulch pits to retain rainwater in gardens

 Mulch pits are a simple way for students to begin a rainwater garden.  Find spots where water is already accumulating and even over-saturating the soil.  Dig a pit and fill it with sand and mulch in 3:1 ratio then cover the pit with topsoil. These materials retain rainwater in the garden and keep it from becoming run-off that carries with it top soil and water so needed in our Northern Californian eco-system between storms and in the dry months from April-November.  Once you dug and filled the mulch pits, observe them over time.