County, PRWID Consider Options for Aerial Survey
Carbon commissioners decided last week to join with the Price River Water Improvement District and interested agencies in obtaining detailed aerial photography of portions of the county.
On July 19, representatives of PRWID requested the partnership of the county in paying for the aerial survey.
The Utah Automated Geographic Reference Center has announced that it plans to conduct an aerial photography survey of all of Utah.
The United States Department of Agriculture and the AGRC have conducted similar aerial surveys previously and made these images available to the public as well as other governmental agencies.
During the survey, the entire state will be surveyed using one-meter telephotography. The images are accurate to one meter.
During the county discussion, Ben Clement, who oversees the county's geographical information system or GIS, demonstrated the quality of the one meter imagery which will come out of the survey.
In addition to the aerial photography of the entire state, local agencies have been given the option of piggybacking more detailed aerial surveys with the statewide survey.
Local agencies can choose to add surveys which will produce one-foot imagery or more detailed imagery.
Clement demonstrated the difference between the one-meter images and the more detailed one-foot images. In the one-meter images, cars and similar-sized objects show up as simple rectangles.
In contrast, objects as big as a car or truck have some detail in the one-foot imagery.
One of the areas where this level of accuracy could be useful is to design and construct a better road through Nine Mile Canyon.
Clement explained that with one-foot imagery, designers could specify how to construct the road almost down to the shovelful of dirt that needs to be moved.
Another type of survey that can be piggybacked on the statewide survey is detailed digital elevation models.
These DEMs provide not only the latitude and longitude as shown on a map, but also show a elevation values for every 10-by-10 meter quadrant. This gives a three-dimensional effect to the date supplied by the survey.
Clement said that the most accurate DEM statistics available in Carbon County are 10 square foot models.
The statistics provide an elevation for every 10 square feet.
One of the options for a piggybacked project is a two square foot model.
A two-square foot model is 25 times more accurate and more detailed than a 10 square foot model.
The more detailed DEMs are part of the reason PRWID is interested in participating in the aerial survey, said Jeff Richins, assistant manager for the water improvement district.
Richens explained that with the elevation models and more detailed aerial photography, the water district could plan the placement of sewer and water lines more accurately.
PRWID is interested in having a survey performed on approximately 130 square miles in Carbon and Emery counties.
The region would extend from just north of Helper to the Miller Creek area and from Gordon Creek to Wellington.
The county planning and zoning office could benefit similarly from the more detailed survey data.
County planning director Dave Levanger told commissioners that he supported piggybacking projects onto the aerial survey.
Levanger suggested exploring the options of including the Nine Mile Canyon corridor and the Scofield area into the survey, as both of the areas have been experiencing increased development.
However, the added benefit to county agencies and the water improvement district comes with a price.
The total cost of the piggy backed projects could range as much as $128,000 or be as low as a few thousand dollars.
The large gap in possible costs is due to questions regarding how large of areas can be grouped together into one project for the aerial surveyor. As the size of a project increases, the cost per square mile decreases.
Sevier and Emery counties have both expressed interest in having portions of their counties surveyed. In order to connect the isolated regions into one larger region, the state could pay for more detailed surveys of the connecting regions. The hope is that by connecting the various projects into one, the state can help lower the cost per square mile surveyed.
If Carbon County were to piggyback surveys on top of the statewide survey, costs would be billed at approximately $200 per square mile. If the county merges with other counties, into one larger project, the price drops to as low as $90 per square foot.
Richens told commissioners that PRWID was prepared to provide $15,000 toward the survey at this time. The county or other agencies would have to come up with funding for the balance.
One possible source for such funding is the Carbon County Recreation and Transportation Special Service District. The district has discussed the possibility of paying for an aerial survey of Nine Mile Canyon in the past.
Using this information, the special service district could accomplish that goal and help collect data which would be useful in addressing future transportation and recreation concerns.
And while there are significant costs to the survey, the prices available by piggybacking are much lower than what they would be if the county did the surveys on their own.
An aerial survey of Nine Mile Canyon, for instance, was estimated at more than $125,000 recently. That region is smaller than the areas considered by the county.
As a result, county officials could see the cost savings if the project were done as part of the statewide survey. Even if Carbon County cannot take advantage of grouping the project with Emery and Sevier counties, a survey which included not only the PRWID region, but added hundreds of square miles in Nine Mile Canyon or Scofield, would cost somewhere in the neighborhood of $100,000, still lower than figures estimated for Nine Mile Canyon alone.
"I think this is going to save is thousands of dollars tomorrow," said County Commissioner Michael Milovich.
The question of whether the county could group the projects together was set to be discussed earlier this week by ACRC representatives and the company performing the survey.
The outcome will determine the actual costs associated with the project.
While the county commission and PRWID representatives agreed to partner in the survey, the overall scope of the survey will need to be determined.
During the meeting, it was unclear if the data provided would be adequate for plans in Nine Mile Canyon. If the agencies can drive costs down, they may pay for a survey of a larger area.
If costs remain at a higher rate, the survey could be limited to only the PRWID district.