A surface runoff is the rainfall that runs over the earth when it is not absorbed. It can occur if the earth is hard and crusted over from excessive exposure to hot sun such as in a desert. Areas such as California and Arizona experience a great deal of surface runoff during the rainy season, also referred to as monsoon season. The rain is very hard and comes quickly only a few times a year. The earth has been essentially baking in the sun all that time and the mass amounts of water tend to run off instead of sinking into the dirt. This is one reason that they have what are called washes in the area to direct the flow of water away from houses and roads for safety.
When it comes to construction sites it is important that you consider the direction of surface runoff. Installing stormwater drains is vital if you want to save the construction or building from suffering severe damage from excessive water damage. Additionally, making sure that the surface runoff is directed away from your driveways and the foundation of the building is necessary. Surface runoff is an important issue for environmental protection agencies as well. Often the surface runoff can contain contaminants that are damaging to the environment. There are many rules and regulations regarding how to handle surface runoff, particularly if you own or operate a business that has chemical waste that could end up in the surface runoff and run to other locations contaminating the soil.