Q: What is a topographic survey and why is it needed?
A: A topographic or topographical land survey shows the height, depth, size, and location of any given parcel of land, it also shows the changes or contours in elevation throughout the parcel. A land surveyor will often include existing buildings and structures, boundary/property lines, ground surfaces, tree positions, and drainage details in the topo survey.
The information is typically shown in the form of spot elevations, contour lines and contour elevations, utility lines, utility cover elevations, benchmark reference etc.
Additional details can be added to the survey, and the results will be often delivered as CAD files.
A topographic survey is conducted generally for the following use :
- Grading permits for building site and architectural projects
- Environmental restoration and property improvements
- To fulfill regulatory requirements for construction codes
- Drainage plans, Utility connection plans
- When land developed for one purpose is being used for another purpose
- Land division
Q: What is a boundary survey?
A: A boundary survey is a means of defining the limits of a property formally. It mainly focuses on the definition of the corners of a plot, property lines showing distances and bearings, easements etc. People usually perform boundary surveys before they buy, split, improve, or build on the land. The professional land surveyor conducts the survey because measurements must be as accurate as possible.
- A boundary survey identifies any encroachments (driveways, fences, buildings, etc.) on the property or crossing any of your boundary lines.
- A boundary survey and drawing provide you the exact property line measurements and locations of all structures (houses, barns, etc.), fences, or driveways related to those property boundary lines.
- A boundary survey is the first step in being able to subdivide your property.
- A boundary survey should be done to make sure the building you’re constructing is properly placed on the lot, and not encroaching on any easement lines or surrounding properties or right of way.
Q: What are Civil Plans/Drawings and why are they required?
A: Civil Plans are the technical drawings that show information about the site details. As per the California law, there are many circumstances in which the local authorities provide permit/approval for construction only after the owners submit the civil plans/drawings signed and stamped by licensed civil engineers. Some examples of Civil Plans are Grading & Drainage plans, Tentative parcel map, Off-site improvements plans, Retaining Wall Plans, Utility connection Plans for water, storm drain, and sewer.
Q: What is required to start with the Civil Engineering work?
- Grading and drainage plans - To start with the Civil Engineering work for any project a civil engineer requires site plan from the Architect and topographic survey from land surveyors in CAD (Computer-aided design) and Pdf.
- Land Subdivision- Projects like dividing the parcel of land into different lots requires soil reports to work on Civil Plans. Usually a site plan is required if available, else we create a civil site plan or Tentative map with Architect’s inputs.
- New Construction- New Construction like a custom home requires soil reports to work on civil Plans. Landscape plan if separate from site plan
- Accessory Dwelling Units- For ADUs a soils report is required only if infiltration is used as a BMP Measure or required by the city or if its a steep site.
- Remodeling of Existing Structures - A soils report is required only if infiltration is used as a BMP Measure or required by the city or if its a steep site.
- Utility Design - Utility As-Built drawings from the agencies, topo only for the area that has to be graded or the nearest street mains
- Septic Tank Design - For Septic tank designs a soils report and a percolation test is required in order to obtain the civil plans.
- Retaining wall Grading and Drainage Plans- You might require soils report to get the grading and drainage plans for the retaining wall.
- Stormwater Compliance - For projects which cover the scope of stormwater compliance, requires soil report from the clients to start the civil engineering work.Landscape plans may also be needed as per the scope.
- Private Driveways- For large private driveways that have fire dept requirements, we need a separate landscape architect/designer (based on the city requirements) who can obtain the landscape permit. (e.g. LA, SF), soils report is needed for grading and pavement recommendations.
Q: Why do I need to have a topographical survey as well as a soil report for the civil scope?
A:Topographic survey is required by many local government bodies in California to determine the existing conditions and elevations of a site. For Civil Engineering scope, a topographic survey is needed to know the existing elevations, contours, property lines, utility lines, invert elevations, benchmark, and other important information.
Soils report is needed to understand the site conditions, seismic hazards, recommendations for grading cut and fill and trenching, retaining wall backfill etc.
Q: Can I find a topographical survey for my property in the city?
A: There is a possibility of finding the topographical survey of your property in the city. In case the Topo surveys are available the following things need to be considered -
- The Survey report might be very old and needs to be checked if it has all the necessary information required to work on the Civil Engineering Scope like elevations, contours, existing features etc..
- The Topographic survey is signed and stamped by a licensed surveyor.
- The Survey report can be converted into CAD (Computer-aided design)
Q: What plans do I need for a subdivision, new home, addition, etc?
A: The plans and reports required are usually based on the city/county requirements and the plan checker’s discretion.
- Subdivision - Site plan, Tentative map, Grading and drainage plan with earthwork quantities, Stormwater management measures like a detention pond/ LID measures, Utility Plan, SWPPP (Sites > 1 acre).
- New Custom home-Grading and drainage plan with earthwork quantities and per soils report recommendation, Stormwater management measures like a detention pond, LID measures/C.3 checklist, erosion control plan,Hydrology report may be needed, WQMP, SWPPP (Sites > 1acre)
- Addition/Remodel-Grading and drainage plan with earthwork quantities, LID measures, WQMP may be needed, erosion control plan.
- ADU- Grading and drainage plan with earthwork quantities, LID measures may be needed, erosion control plan.
Q: Does the civil engineer need to come on-site?
A: In most cases, on-site visits of Civil Engineers are not required. Unless there is a specific drainage problem at the site or the topographic survey and site plans are insufficient.
Q: What is the Civil Site plan and why is it required?
A: A civil site plan is an engineering drawing that shows usually small driveways or long private driveways with turnarounds, parking, drainage facilities, sanitary sewer manholes, water meters, fire hydrants, visible utility covers and other detailed information about the site to meet development needs. Civil Site Drawings should comply with local development codes.
A Civil Site plan is different from an Architect’s Site plan. In case of large private drives, the city/county may ask for a Civil Site plan which is a Site plan signed and Stamped by a Licensed Professional Engineer.
Q: What is a tentative map and how is it different from Final Maps?
A: As per California law, a Tentative Map is, “a map made for the purpose of showing the design and improvement of a proposed subdivision and the existing conditions in and around it.” A Tentative Map depicts the proposed division of land and provides additional information, project notes, grading amounts, proposed ownership and maintenance, existing vegetation, drainage patterns, etc.Prepared by a licensed Civil Engineer the Tentative Subdivision Map is the parcel configuration proposed prior to a final or parcel map, the official recorded document.
A Final Map is the map that establishes the new legal lot lines and is recorded at the city/county office. It is prepared by a licensed Land Surveyor. It depicts dedications, owner’s statement, survey points, and meets and bounds depiction of new lots and easements. Once a Tentative Map is approved, the Final Map must be submitted and recorded before the Tentative Map expires by the Owner.
*Note: The content published above was made in collaboration with members of Design Everest.