development of KRWA mapping program
GPS Mapping at Kansas Rural Water consists of two components: data collection and map production. A multitude of methods exist to collect system data, ranging from pencil drawings to digital CAD drawings. The five primary methods that have been investigated in the process of data collection by Kansas Rural Water are:
heads up digitizing over scanned engineering drawings
heads up digitizing over digital orthophotography with engineering drawing reference
automated raster/vector conversion
and field data collection
KRWA has determined that the best process for data
development is a combination of two processes: heads up digitizing over digital
orthophotography with engineered drawing reference augmented with field data
The data from the field collection is imported over the digital orthophotography. If the scale and projections are correct, the points appear on the aerial just where they are in the real world. The heads up digitizing begins with the placement of non-visible system features, those that could not be field collected, over the aerial. Referring to the engineered drawings aids in the correct placement of features such as line locations and the correct layout of pipeline configurations, such as valve intersections. The field data collection is crucial in that it shows the exact placement of a feature versus a close approximation through the digitizing process.
How does the process work?
A city or RWD contacts KRWA expressing an interest in GPS mapping. A KRWA representative will lead the system representative through a short pre-assessment survey to determine what the system needs and how KRWA can best provide that.
After the city or RWD decides to proceed with the GPS mapping, the next step is to collect data. The field data collection involves using GPS equipment to record the coordinates of visible system features (valves, hydrants, meters, trenches, markers, etc.). The accuracy of the equipment used by KRWA is within one foot of actual location of the feature. This means that after a point is collected with KRWA's equipment, it is possible to navigate back to within one foot of that exact position with comparable GPS equipment. One-foot accuracy is very adequate for water and wastewater utilities.
It is essential that the city or RWD participate in the data collection process. Time in the field is minimized and accuracy is increased if the system representative drives the vehicle to the desired locations and the KRWA technician records the data. The system representative knows the system and the KRWA technician is able to do a better job logging the information.
KRWA provides cost estimates for the data collection of a water or wastewater system. The estimated cost is based on the number of features to be data collected. KRWA charges an hourly rate based on the number of points to be collected. If the utility is prepared for data collection by pre-locating and marking all features to be collected, the data collection can be performed more efficiently, thus reducing the overall cost of the project.
What does the system receive?
KRWA's map production can generate printed maps and a digital map file. The printed maps can be large-scale wall maps, 42" by 42+", showing the major features with just about any layer desired (aerial photos, streets, sections, railroads, rivers and streams, etc.).
The printed maps can also be generated
into a map book format. The map book is a bound 18" by 24" book of high-detail
maps printed at whatever scale the utility desires. An index of detail sheets is
also included. The digital map file can be viewed and printed with free software
that KRWA will provide. The software and file can be used on nearly any
Feature attributes, details such as size and date of installation, can be added and edited with additional programming. The city or RWD can also utilize after-market products such as hand-held computers in conjunction with a GPS attachment in order to navigate in the field. The possibilities are limitless and the costs incurred with developing a Geographic Information System are solely dependent on the needs of the utility and its future intentions.
KRWA will be here to help you develop and implement your mapping to meet future
needs of your utilities and your community. The main advantage KRWA guarantees
is that you will be in control of your data. You will not find any more
reasonable costs for these services.
KRWA is prepared to respond to your interest by providing a pre-assessment. KRWA staff also are pleased to attend a meeting of your board or council to further discuss and demonstrate how you can obtain better quality maps at affordable costs. Email GIS Coordinator, Pete Koenig at email@example.com.