What slope is too steep?
What slope is too steep? Steep slopes are legally defined as hillsides having a 15 foot, or greater, vertical rise over 100 feet of horizontal run, or 15% slope (Figure 1). They are often undesirable ar- eas for development due to the difficulty of building on steep grades.
Is a 20% slope steep?
Understanding slopes and gradients Less than 10% incline is considered slight and is the easiest to build on. Around 11-20% is considered moderate and gradients above 20% are considered “steep”.