To locate an underground downspout, you should start by identifying where the above ground gutter drains. Look for an entry point, such as a pipe or elbow leading into the ground. Follow the surface path for signs like depressions, landscaping disruptions, or wet areas after rain. You can use a metal detector or plumber’s snake to trace the pipe underground. For deeper pipes, a professional locator tool or camera inspection may be necessary. Visual markers or utility maps can also guide the search.

In most areas, you will need a permit for excavation work, even for projects that only involve grading or yard leveling. Permit requirements depend on your local government and the scope of the project, but they are especially common for significant digging or work that could affect utilities or public property. These permits help protect the local topography and prevent drainage issues. An experienced excavation company will typically know whether permits are needed and can often handle the process of pulling and closing them for you. You can also verify permit requirements by contacting your local building department and describing your project.

Excavation and grading are both generally necessary for designing your foundation, and leveling the ground where your foundation will go. These steps can also prepare the area by removing vegetation and anything else that could interfere with your home’s foundation.

Trenches are typically 12 to 24 inches deep and 8 inches wide. However, the required depth depends on the specific project and local ordinances. For example, a French drain may need to be 18 inches deep, while a water pipe might require a depth of 24 inches and a drainage pipe 36 inches. Your city or county may have specific regulations, so it's wise to consult with an excavation professional to determine the correct depth for your project.