Helix Water District’s survey crews have been an integral part of the District’s day to day operations since the early 1900’s. In those early days, survey work was performed with levels to measure elevation, transits to measure horizontal and vertical angles, and chains to measure distance.
While the type of work we do has remained the same — providing Helix engineers with critical data for planning, design and construction — those early tools have been updated by advancements in technology.
Surveyors use levels to measure elevation. At right is a model from the early 1900s and a model used today.
Transits are used to measure angles. At left is a model from the early 1900s and a model used today.
Today, Helix crews are equipped with GPS (global positioning system) receivers driven by electronic data collectors connected via Bluetooth technology, and synchronized via modem with a real-time network that allows for instantaneous positions that are accurate within one centimeter. This new technology also saves time by eliminating line-of-sight obstacles and heat wave refraction. It reduces the chance of equipment theft, as well, since our equipment remains with the survey crew at all times.
How Surveying Supports Project Design
These advancements allow Helix survey crews to perform highly accurate surveys at any position within district boundaries. And, keeping all projects and facilities tied into one coordinated system allows for seamless data transition into our districtwide GIS (geographic information system) database. These capabilities are vital during the design of new projects, such as the replacement of cast iron pipeline and the construction of new reservoir tanks. Survey crews collect existing topographic features, ground elevations, and utilities locations in the field, then download the data into AutoCad files and send it to engineering staff for design.
Left: Dave Moore, Survey Technician, and Scott Gregg, Senior Survey Technician, staking out pothole locations for a capital improvement project and recording each location with GPS. Right: Cameron Scott, Survey Technician, using GPS to locate an existing pipeline for a large valve replacement project.
How Surveying Supports Construction
Helix’s surveyors also locate existing boundary (property) line monuments to ensure that new facilities are located within established easements and right-of-way. Once these projects are designed, survey crews return to the field and provide construction crews with survey stakes to ensure accuracy of construction. Quite often, construction crews must remove a property line monument in the work area. Before they do, the construction crew will contact the surveyors to document its position.
When construction is completed, the survey crew will replace missing monuments in the original’s exact location and Helix will draft and submit a map to the County Surveyor office to be recorded. The crew will also collect final as-built locations for inclusion in the record drawings inserted into Helix’s GIS system. Collecting these accurate locations helps ensure that facilities can be easily found in the future for mark-out, repair or replacement.
Survey crews also work closely with Helix’s right-of-way staff, monitoring Helix’s easements and main transmission lines quarterly to ensure that no new construction has infringed upon or blocked access to an easement and that Helix’s facilities are not damaged.
As Helix moves ahead in providing our customers with safe, dependable drinking water, the Survey Department will be there, continuing to play its vital role in maintaining the district’s infrastructure.