Civil engineers reading a grading plan at a construction site

The construction or renovation of a residential property is an uphill task undertaken by multiple stakeholders. The same also demands the use of disparate resources that are either developed or supplied by numerous vendors or consultants.  A grading plan is one of them. Most homeowners will be aware of what a grading plan is. But not everybody would know how to interpret the details in it. A thorough understanding of the grading plan, by all the stakeholders, can actually help in more ways than one.

Site grading refers to the adjustment of the elevation of the soil around the home. This is done to define and establish controlled drainage patterns so that stormwater flows outwards and not towards the building. When water flows towards the building, the consequences can be disastrous. Professional grading even eliminates expensive corrective work after construction. The rework could involve retaining walls and drainage systems. In certain scenarios, it could even prevent a total re-grading job. Sometimes, re-grading could become more complex than expected. This is because the person doing it may have to go back to the drawing board, consider even new factors, and proceed with the grading assignment. Since it’s a rework, there’s no scope for errors at this juncture. In terms of the costing, a grading job can vary anywhere between a couple of hundreds of dollars to a few thousands.    

A grading plan is a construction drawing that shows the proposed grading of a site. It comprises an outline of the site. Most importantly, it shows the location and elevation of all the drainage structures within the premises. A professionally designed grading plan can help save on overall material movement, thereby resulting in significant cost and time savings. It’s a no-brainer that construction professionals are adept at reading a grading plan but they expect all the essential details. Even the homeowners can learn to read a grading plan if they are aware of the basic terminologies and information categories in the same. 

  • Contour lines ‒ These are contour lines that connect points on the same elevation and also highlight the grade/slope.
  • Spot elevations ‒ Also known as spot grades, spot elevations identify the exact elevation of a point on the surface of the land on which the property stands.

  • Berms ‒ These refer to mounds/small hills of soil that are created to direct the flow of water in a particular direction, and also to enhance the aesthetics of the landscape.

  • Swales ‒ These are valleys, low lying areas, which are defined to direct the flow or a part of the flow in a specific direction.

  • Ridgelines ‒ These lines refer to the linearly defined high points across the property.An engineer has to keep in mind multiple parameters before proceeding with the design of the site grading plan. Aside from the above basic technical elements, information on the below components is a must.    

Property

The grading plan must have essential information about the overall property. This includes the less technical items such as the address, homeowner/homeowner name, and contact details, to mention a few. The subsequent section will dive deeper into the same by showing what the experts need for the approval, planning, and execution of the grading project. 

Property map with measurements showing drainage plan

Building

The house, along with its supporting structures, is the most important component in a residential property. A grading plan features multiple details about the building to be constructed or renovated. The exact location and type of building are a must in a grading plan. Other elements like driveways, tree cover, and easements are also shown on it. Lot grading is done to protect the main building from stormwater that flows inward, thereby damaging the foundation. A foundation damage can, in turn, affect the main structure in the long haul. Even a new building and driveway on a vacant property creates additional impervious areas where the amount of storm water running off the site is increased. A thoughtfully designed grading plan takes all these factors into consideration. 

Drainage

Proper drainage is indispensable for the life of every residential property. If improper, it can be detrimental to the structure and life of the people in it. Drainage arrows, showing the runoff route across the property, are a must in every plan. These arrows not only show the direction of the flow of water but also the property lines through which the water flows. Also, the reviewing authority can check the plan to know if the stormwater is being properly managed according to governing code/regulations. 

Erosion

There are multiple factors, like steep slopes and rainfall, which make soil susceptible to erosion. A grading plan shows the location, and methods of erosion & sediment control in a property. Erosion control prevents movements and sediment control keeps the eroded soil in place. The plan gives a clear picture of everything an engineer/contractor needs to know about the safety precautions that should be taken. No homeowner expects surprises when it pours or snows! 

Walls

A retaining wall is one of the most prominent residential structures that resist the lateral pressure of the soil. The lateral pressure could be a result of numerous factors like earth filling and liquid pressure. A residential grading plan shows retaining walls with top and bottom elevations. This part of the plan also shows steep slopes and other grading features that are relevant. 

Got questions on grading plans? Our team of experienced California-licensed engineers can help you with the right advice and services.

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

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