What Is Site Grading?

Site GradinG and the LeGaL requirementS 2

In this chapter you will learn about:

• Site grading and why it is important • The practical and aesthetic considerations of site grading • How grading can be used to avoid or minimize various slope failure issues or area flooding • The relationship between landscape architects, architects, and civil engineers as a team or collaborative enterprise • Site grading as an integral component for achieving professional licensure

What Is sIte GradInG?

Site grading is a process requiring a set of technical skills and understanding of a specific body of knowledge. The two are used together to guide the designer in modifying the existing topography of a project site to achieve functional objectives and accommodate program elements. Think of grading as land sculpture using the medium of topography to achieve a desired three-dimensional result. A sculptor might use clay, wax, or a whole range of materials to create three-dimensional forms. The materials or tools that landscape architects use to develop their design goals may initially involve clay, but eventually their

three-dimensional explorations—regardless of the materials—must be transcribed into two dimensions: line drawings with notes. Although these drawings and notes involve mathematical calculations, in order to create the correct slope or elevation, this does not mean that aesthetics and the design process are not relevant.

The answer to the question “What is site grading?” or “What is the purpose of grading?” has four basic components: 1. Grading is a process for reshaping the topography of an existing site to accommodate programmed uses (such as a sport field or parking lot) and built structures (such as a residence, a school building, trails, or roads). The design of the pedestrian ramp and landscape in Figure 2.1 heavily relied on site grading. Grading is an essential component for all project scales involving properties as large as several hundred acres (in the case of a new residential subdivision) or as small as a half-acre (for a children’s playground) or a 400-square-foot residential backyard.

Figure 2.1 Grand Park, Los Angeles, CA. Grading to provide wheelchair access connection from upper to lower park areas.

rios CleMenti hAle studios

2. Grading is necessary to reshape existing terrain not only to accommodate intended uses or built facilities but also to redirect surface water flow away from areas where the water is not desirable. Surface water can also be collected for some purposes, such as irrigation; allowed to infiltrate into the underground aquifer; or, as is more common, directed to a storm water system. See Figure 2.2.

Figure 2.2 Bioswale for recharging surface water runoff to aquifer, Phoenix, AZ

3. Grading and the creating of landforms can be employed to achieve an aesthetic goal and to help shape and create outdoor spaces as part of a complete design scheme. Such an outdoor design might include plantings, walls, water features, and hardscape. See Figure 2.3. 4. Grading and the creating of landforms can achieve specialized purposes such as water conservation and management or access control and site security. Figure 2.4 shows a small lake created by the landscape architect as a source of irrigation water, for aesthetic reasons as well as to provide a cooling effect in a hot, dry climate.