The field of civil engineering can be confusing to navigate. The term encompasses many different engineering functions, such as structural, transportation, and environmental engineering, while also referring to a specific subset of engineers that focus on the civil discipline. This includes many things, such as preparing sites for roads, bridges, and new buildings. Civil engineers often get involved in the first, vital part of large projects before structural engineers can begin to design the structures.

But even the smallest residential and commercial projects sometimes need civil engineer services. From preventing flood damage to your property, to ensuring adequate sanitation procedures, civil engineers can provide fulfill important functions. So, what is it that they do exactly?

Civil Engineers: What Do They Do?

One of the world‘s oldest professions, civil engineering developed our civilization’s infrastructure. Roman civil engineers connected their vast empire with roads, brought fresh water to cities and farms via aqueducts, and took steps toward promoting health and sanitation with a network of sewers. From its ancient roots in the design and construction of public infrastructure, the discipline has branched out to cover areas such as soils engineering, maritime and hydraulic engineering, transportation, traffic planning, energy production, and public health and safety.

Although civil engineering is primarily focused on public works, its elements also apply to the private sector. A residential civil engineer can offer a spectrum of services that prepare your site for construction. These include:

• site planning
grading design
• drainage planning
• sanitary drainage planning
• erosion and sediment control
• floodway construction
• handling of grading and erosion control permits

The guide below explains the impact these services may have on your construction project.

Site Plan

Site plans must be submitted with most permit applications in California. The purpose of a site plan is to show the proposed changes to a specific lot. A site plan will typically include existing and proposed structures, contour lines showing the elevation of terrain, parking, roadways, landscaping elements, easements, utility connections, and sanitary drainage.

Grading design depicting areas of excavation and filling, proposed terrain elevation changes, and stormwater management is a major element in most site plans. That said, many jurisdictions in California require a separate grading plan. In either scenario, a civil engineer will have to plan these site features and draft a set of plans to be submitted with your permit application.

A new custom home in San Diego for which Design Everest provided the Civil Engineering plans
A new custom home in San Diego for which Design Everest provided the Civil Engineering plans
A new custom home in San Diego for which Design Everest provided the Civil Engineering plans

Grading Design

The purpose of grading design is twofold. First, it aims to level and stabilize the soil around the proposed structure. Second, it plans for the safe and efficient diversion of stormwater off the site, thus preventing the collection of standing water on your property.

Grading involves cutting (excavating) and filling (depositing) soil where needed. California Residential Code requires foundations to be placed no less than 12 inches below undisturbed ground surface, and your contractor will have to excavate to at least this depth. If you are planning a basement, you will have to excavate deeper. Depending on your site‘s topography, your digging swales - low lines that help channel storm water off your site - may also be necessary. Filling replaces soil around the newly erected foundations, but may serve other functions. Your contractor may place mounds of soil to create berms and ridges - drainage mechanisms that control storm water flow.

As cutting and filling costs increase with every cubic yard of soil displaced on your site, a good civil engineer will try to keep these costs down by minimizing the export and import of soil. This economy can be achieved by taking advantage of the existing topography and by using as much of the excavated soil as possible when fill is needed.

Drainage Plan

On smaller residential projects, the drainage features are included in the grading plan. If your authority having jurisdiction requires a separate drainage plan, it should depict at least the following features:

• grates
• invert pipe elevations at catch basins
• flared outlet structures
• erosion control measures
• existing and proposed berms, ridges, swales
• indication of where runoff will go after leaving the site 

 If required, your civil engineer can prepare your drainage plan for submission to the building officials. 

Sanitary Drainage

Aside from designing storm water drainage, civil engineers will also plan sewer laterals. These are the pipes that carry human waste from your building to the public sewer. The quality of these systems is vital to public health and the environment, and most jurisdictions in the State, as well as the Environmental Protection Agency (EPA), demand that sewer laterals meet certain design and quality criteria.

sewer permit is required in most jurisdictions if a new connection is being made to the city‘s sewage system. Your civil engineer can help prepare the necessary documents to support this permit application.

Erosion and Sediment Control

Erosion is the movement of soil caused by rainwater runoff. It happens naturally over time, but the disturbance of soil caused by construction activities can expedite and amplify the process. Soil that gets washed away during construction may settle in storm water pipes and bodies of water, causing damage to drainage infrastructure and natural habitats.

Your civil engineer can control this destructive process and mitigate its effects with sound erosion control measures. These can include identifying the source of stormwater pollutants on the site, limiting the amount of exposed soil on site, using silt fences to prevent sediment from leaving the site, and diverting storm water into areas with vegetation.

Most jurisdictions in California require an Erosion and Sediment Control Plan to be submitted with the grading plan. At a minimum, it should include the following information:

• project background information
• site information
• area of soil disturbance
• project start date
• grading start and completion date
• project completion date
• proposed erosion control measures
• proposed sediment control measures

Your civil engineer can plan and oversee erosion and sediment control measures, and can help prepare this plan on your behalf.

Natural Disaster Planning

California is situated in a disaster-prone region. Despite this, every natural calamity that strikes the State brings about new construction practices that help us build better. While structural engineers prepare our buildings for earthquakes, their civil counterparts can mitigate the threat of floods and ensure building safety.

Floodways are defined as the channels of a watercourse and their adjacent floodplain. Any new construction in a floodway will form an obstacle to floodwater, and as such, must be designed to not increase the upstream high-water elevation above a pre-established Base Flood Elevation (BFE). Building in such an area may require a Floodway Encroachment permit from the Federal Emergency Management Agency (FEMA), among a series of other conditions. Your civil engineer may help you ensure compliance with all applicable local, state and federal ordinances.

Design Everest Can Help

We are a team of licensed civil engineers who can lend a hand with all the services described above. Contact us now and we will provide you a FREE Consultation with a quote. We also provide virtual on-sites and virtual consultations.


*Note: The content published above was made in collaboration with members of Design Everest.

Verified by Matthew Burkert PE

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