Erosion controls go hand in hand with permeable lots — both are intended to prevent overloading of storm sewers and reduce storm water runoff, which can damage the soil and water quality of surrounding water bodies. For one point, we can either
a. use terracing and retaining walls where portions of the lot are located on a steep slope (which ours is not), OR
b. plant one tree, four 5-gallon shrubs, or 50 square feet of native ground cover per 500 square feet of disturbed lot area (including area under roof).
To meet section b, which I’m sure we have, we just have to do the calculations. Our lot size, which is about 17,800 square feet, is assumed to be 100% disturbed. It pretty much was. For that square footage, and for this point, we will need to have planted 35.6 trees. We planted 81 techny arborvitae, 5 serviceberries, 3 white pines, and a partridge in a birch tree.
That gives us one point easily. Again, I don’t think this was incremental cost to go for this point on its own — we wanted to plant those trees regardless of our concern for erosion control.
Sustainable Sites points so far: 8
Cumulative points: 22
Additional points needed to get to Gold: 66