Plan of Topography
Topographic plans, or “topos,” show the physical properties of a site. They assist architects, engineers, and planners at the design stage of the land development process. Features shown on plans of topography may include ground elevations, walkways, ditches, swales, catch basins, manholes, retaining walls, curbs, and trees.
Plans of topography are needed for the design of homes, larger subdivisions, parking lots, and generally anywhere where someone needs to know “what’s on site.” On larger sites, contour lines may also be generated to better illustrate the profile of the ground surface.
Topography is often included with surveyor’s real property reports. This is done to illustrate the legal aspects as well as physical features on one plan of survey. SRPR with topography is especially useful to those who need to account for zoning constraints in their design. In housing development, the most common restrictions include minimum setbacks from property lines and maximum height of the proposed building. Knowing the size of the parcel, along with its ground profile and existing features, allows for a design that is compatible with the site and one that the municipality can accept.
Plans of topography enable architects to design houses that fit within the existing elements of the site. The following examples demonstrate how topos are instrumental in architectural planning:
- if the front of the lot is much higher than the rear, a walkout basement may be necessary
- if there is a ravine at the back of the property, the new house might have to be built a certain setback from the stable top of the bank
- if the property is in a floodplain, then special considerations may have to be made
- if the site is flat, then the new development must account for water being drained away from the site after the build is complete (in general, site drainage has to be self-contained on the subject lands)
Because topographical plans display some overlap of the neighbours’ land in addition to the subject land, architectural designs can accommodate surrounding properties where there is no work planned.
Plans of topography, in conjunction with the architect’s site plan, are integral in the process of creating a grading plan. Topographical plans may also be used for landscape design and aren’t always made specifically for later grading plans