landscape design - plans
Tookoo Landscape Design
0.3%-1% = Underground storm drains. 0.4-1.4% = Underground sewer. 0.5-1% = Surface min. 2% = Away from buildings. 2-10% = Drainage ditches. 25% = Grassy slope max. Must be landscaped to prevent erosion. 50% = Ground cover max. Over 50% = avoid. Must be terraced to prevent erosion.