Is a 20% hill steep?
Is a 20% hill steep? It doesn't matter exactly what it means, 20% is steeper than 10%. In surveying 20% is interpreted as 20% of a right angle (i.e. a brick wall) and so would be 18 degrees.
What is considered a steep hill?
Page 1. 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.