by James Pearson
In the world of site design, those of us who design land development projects (mainly civil engineers and landscape architects) consider ourselves very good at launching straight into design. After all, there is nothing better than getting a great idea down on paper, which is when we feel we are at our best. However, good design needs to start with a thorough understanding of the existing conditions.
Existing conditions information usually comes to us from a surveyor, often supplemented with information from old record plans, but it is often too easy to jump straight into design without spending enough time assessing the information we are given about the existing conditions. This may feel like it slows the design process down, but my contention is that it can pay huge dividends in time saved as the project progresses.
It comes as no surprise to those of us with sufficient experience that surveyors, as good as they are, don’t always deliver a perfect work product, yet there can be a tendency to take a surveyor’s topographic and utility survey as gospel. It is critical to develop a smooth workflow and to follow it consistently when evaluating existing conditions data.
The best evaluation is done on a very technical level, doing a deep dive for example into a CAD file to understand things that may not be clear on paper. Some practical tips that should be considered in a workflow include the following:
- Request that the surveyor provide individual survey points in their deliverable. Each point typically includes an abbreviated description of what the person in the field believes they were surveying. Looking at their raw data points can shed light on how they interpreted certain land features.
- Sometimes topographic contours just don’t seem to look right. Reviewing the raw data points can help identify problems with the contours. Sometimes grade break-lines or outer edges of a survey get omitted and the software can create erroneous contours.
- Take the time to go through a survey CAD file and translate information onto a layer system and format that is compatible with your design documents. This will make for a nicer looking finished product while also allowing the designer to become better acquainted with the data.
- If the surveyor was hired to show existing utilities, independently verify if any seem to be missing or incomplete.
- Review the raw survey data points to better understand which utilities were drawn based on field observations and which are shown in an approximate fashion based on record maps.
- Remember that the surveyor may not know what everything is that they find in the field. For instance, a manhole cover could be mistaken for sewer when it is actually a storm drain. Visit the site with survey information in hand to confirm anything that seems unclear.
There is a mantra that has been attributed to the military special forces, “slow is smooth, smooth is fast,” emphasizing the importance of accuracy, consistency, and a controlled pace in executing tasks. Well, it holds true here as well. By taking the time to implement a workflow with the right mindset, strategies, and skills, we can make better use of existing conditions information, avoid re-design, and save time and money throughout the life of the project.
James Pearson
James Pearson, PE is a technical leader of Site Civil and Utility Engineering at Weston & Sampson in Reading, Mass.
