Subdivision Project Synopsis and Typical Scope of Services

Chastain & Associates, P.C. is proud to have gained valuable experience with many notable projects throughout north Georgia over the last several years. With this experience in mind, we have developed what we like to refer to as our "cook book". In essence, this is a flow chart and explanation of what is involved with developing a subdivision. Although the specific regulations and submittal dates vary from county to county, the same format is applicable to any land planning project.

Segment One - The Base Map

The first step to planning a development is to know what you have to work with. Depending on the level of initial design that is required by the client, this can vary greatly. For example, for a quick look at a tract that a developer is considering, a rough overlay of an old survey with the USGS quadrangle topography map may be adequate. However, a more firm analysis is often desired in order to have a higher level of confidence in the number of lots, the amount of road to be built, etc. The best base map consists of the integration of a new and accurate boundary survey, detailed & accurate topography, and soil information if the lots are to be served by septic tanks.

  1. Boundary Survey. While we can do base map preparation and land planning, we will have to eventually survey the property as we subdivide it. If the property is to be purchased, it is always recommended to have a new survey prepared on your behalf prior to closing. However, time and cost restraints may prohibit a new survey for base map and we do the best we can with what we have to work with.
  2. Topography. While the USGS topography is available for all of the United States, it is not suitable for road design in most instances. Most USGS quadrangle maps in north Georgia are either 20' or 40' contour intervals. While the quadrangle map may be sufficient for a "rough idea" of what sort of yield is possible at the due diligence period, we use 2' interval topography for road design and home site placement. Such topography may be obtained by field surveying for smaller tracts, but a photogrammetric (or "flown") topo, using aerial photography and stereo modeling technology, is more time and cost effective for larger tracts. Development of a flown topo is a three step process. First, the aerial photography is taken. This can either be done on a site specific basis from December through March or existing photography can be utilized that was taken previously during that same time period. Secondly, a control survey must be performed to locate reference points specified by the photogrammetrist on the photos. Lastly, the photogrammetrist uses the control survey data to generate the topographic map, which is electronically transmitted to us for CAD use.
  3. Soils Information. The need for soils information can vary from county to county and also depends on the minimum size of proposed lots. According to Georgia environmental health regulations, any subdivision that has a lot smaller than 3 acres must submit a level 3 soil evaluation before final subdivision approval. Some counties require this report prior to preliminary subdivision approval. Some counties will accept a broader and less expensive level 1 soil evaluation for preliminary approval. There are many soil scientists in Georgia. We can work with any of them or refer a client to some that we have had satisfactory dealings with in the past. Chastain & Associates, P.C. does not engage the soil scientist for the client (their fees are not included in ours), nor do we assume any responsibility for their work as they are private licensed professionals.

Segment Two - Land Planning

At this point we have the base map on hand and are ready to begin planning the client's project. In order to do this, we need to know the client's base criteria such as lot sizes, minimum widths of the proposed lots, and any site specific special requests, such as to emphasize creek frontage or view utilization. We typically develop a preliminary lay-out for client review with many options. After meeting with the client to seek direction, we complete the land plan. At this point the land plan is not a technical drawing that is ready for permit submittal but does show the lots, their sizes, the amount of road to be built, etc. The land plan is usually found to be suitable for appraisals, bank consideration, and (when applicable) rezoning applications. With this information on hand, we can now develop an accurate cost estimate for completion of the project since we then know how many feet of road are to be designed for grading & drainage, how many lot lines are to be surveyed, etc.

Segment Three - Preliminary Plans

Now things begin to get very detailed & technical. The level of detail and intensity depends on the local requirements. Some counties require such intricate requirements as detailed hydrology studies, storm drainage network profiles, future home site placement, location of individual home site's septic tanks & absorption fields, etc. The basic information is required in all counties though, and generally includes proposed road placement, proposed lots (including their approximate dimensions and size), topography lines, soils information, and the Sediment & Erosion Control Plan. The Sediment & Erosion Control Plan (commonly referred to as the "S&E plan") is almost a separate working drawing within itself. Each S&E plan must meet technical requirements set forth by the Georgia Soil and Water Conservation Commission. Each S&E plan is reviewed by an employee of the Natural Resources Conservation Service (a division of the U.S. Department of Agriculture). After any comments are addressed, the plan is approved by issuing an approved "Technical Review" by the local conservation district. Without an approved "Technical Review", a land disturbance plan can't be issued by the local authority. The S&E plan is a very detailed drawing that depicts proposed contour lines after grading, specific sediment control measures such as silt fencing and sediment dams. Measures must be designed and supporting calculations placed on the drawings to demonstrate that a minimum of 67 cubic yards of available sediment storage have been provided for each acre disturbed. Hydrologic calculations for storm pipes and overall project increases are also required. Although we customarily prepare road profile sheets that depict proposed street grades, not all counties require us to submit road profiles. Also, if a portion of the project lies in a flood plain, most counties are required by federal regulations to have the exact location and elevation of the flood plain determined by an engineer. This is a service that we can coordinate with an engineer when the requirement arises.

Segment Four - Monitoring and Reporting

The state of Georgia has been required by federal mandates to adopt a system known as the National Pollutant Discharge Elimination System (commonly called "NPDES"). This program requires that permitted construction sites perform certain mandatory site condition reporting and water quality monitoring and sampling. Chastain & Associates, P.C. does not perform these services but can help you locate a firm to fill this need for you. Failure to comply, including an initial Notice of Intent to discharge stormwater (commonly called an "NOI") can result in multi-thousand dollar fines and delays. Compliance with NPDES should not be taken lightly.

Segment Five - Construction Lay-Out (Staking)

The amount of staking provided on a project depends on the nature of the project and the grading contractor's preferences. A subdivision of small lots and curb and gutter streets requires close adherence to the design location and therefore also requires more staking. A subdivision of larger lots through mountainous terrain often only necessitates a single trip to stake the centerline. While the smaller lot dynamics requires close adherence, the larger mountainous tracts can easily be adjusted to fit the road in its "as-built" location. Some grading contractors prefer a lot of staking, some knock stakes out so regularly that they need a lot of staking, and others prefer to have a minimal amount of staking and more flexibility. The pros and cons of all approaches can vary from site to site and contractor to contractor.

Segment Six - As-Built Survey and Final Plat

After the road construction is completed, we survey the road where it got built (as opposed to assuming that it got built exactly where we staked it). This is known as an "as-built" survey. It is not uncommon for the road location to have shifted from where it was staked. Our as-built calculations establish a right of way that is typically centered on the as-built road location. The new road alignment is then compared to the initial lot design and any imperative changes made. The typical approach is then to have a field crew stake the front corners only and also to sometimes mark the first 100' of the lot lines. At this point the developer can review the lot lay-out on the ground. While it is not uncommon for the developer to "bless" the initial staking and authorize us to complete the lot marking and final plat, we are careful to respect the fact that the land is not ours, it is the developer's. Any desired changes or combinations will be evaluated by our staff and implemented in a coordinated effort with the developer. It is our only desire that the final product is one that our client can be very please with and proud to look back on. Profits have been lost on many subdivisions because unbuildable or undesirable lots have been left due to poor follow-through at the final plat stage. Chastain & Associates, P.C. values our reputation as much as the developer does and wants to leave behind only quality work. Finally, a recordable final plat is prepared and submitted for approval. Upon approval, the plat is allowed to be placed on permanent record in the deed & plat records. Lots sales can then be closed and building can begin.

Wow, what a journey a subdivision can be. I hope that this overview has given the potential developer a better idea of the process and the role that we play in it. We welcome the opportunity to propose on new projects and thank you for your consideration of our firm. We look forward to answering any questions you may have.

Mark E. Chastain, LS (Pres.)