Degrove recently completed a Hydrographic Survey of Lake Panasoffkee for the Southwest Florida Water Management District (SWFWMD). The area surveyed included the open water within Lake Panasoffkee and the centerline of open water portions of Little Jones Creek, Big Jones Creek, Shady Brook spring runs, and the Lake Panasoffkee Outlet River that flows west to the Withlacoochee River. The survey was completed using RTK/GPS with cellular modems at the base and on the boat. Lake cross-sections were surveyed every 1000 feet, and two transect lines were surveyed the length of the lake – perpendicular to the cross-sections. The data from these crossing lines was used to calculate precision statistics for the hydrographic data.
Lake Panasoffkee is a large (over 3200 acres) lake, but very shallow and heavily vegetated. These conditions forced us to use non-typical processing procedures for the hydrographic data collected. Due to the extreme amounts of vegetation, we had to view the echogram of each cross-section line individually, in order to determine and manually digitize the lake bottom – a tedious process. Electronic soundings could not be achieved in some areas, either because the vegetation was too matted for electronic soundings, or floating vegetation was too thick for an outboard motor. In these areas, field crews collected bottom shots using an airboat and a GPS receiver on a 25 foot rod. The base of the rod was equipped with a six-inch plate, which was allowed to come to rest in the silt and mud. This allowed for a consistent lake bottom to be determined. Bottom shots were also taken near the shorelines, where the lake became too shallow for electronic readings or outboard motors. Crews overlapped rod shots with electronic soundings to ensure continuity in the data of each cross-section line. The image seen at the top of this page depicts the data collected. The magenta lines depict hydrographic data, and the yellow lines depict data collected with the airboat and rod.
SWFWMD intends to use the data collected to support decision making in the long-term management of Lake Panasoffkee, and more specifically how the District operates the Wysong-Coogler Water Conservation Structure.
The photographs below illustrate some of the field procedures and conditions. Notice the photo of the floating vegetation.
Degrove President, Ray Niles, has achieved the status of Certified Hydrographer by the American Congress on Surveying and Mapping and The Hydrographic Society of America. This certification is well-recognized in the hydrographic surveying industry. It is also considered by many Federal, State, and Local Agencies when selecting consultants. Ray has been actively practicing hydrographic surveying for over 25 years, and is highly skilled in both hydrographic data collection and processing.
In addition to becoming a ACSM-THSOA Certified Hydrographer, Ray is a Hypack Certified Hydrographer. This is another prestigious certification, as less than 5% of surveyors who take the certification exam achieve a passing score. Hypack’s website states the following about the certification exam:
“Users must demonstrate advanced knowledge in Survey Design, Hardware Configuration, Survey, Single Beam Processing, Sounding Selection, Multibeam Calibration and Processing, Volume Computations and General Hydrography in order to pass. Less than 5% of surveyors who take the test achieve a passing score.”
More about the exam, as well as a list of those who have passed the exam worldwide, can be found at www.hypack.com.
Degrove has had to utilize a helicopter to access places of the Everglades so remote that even our airboat and marshmaster could not suffice. This was in support of a benchmark monumentation and monitoring project for the US Army Corps of Engineers – Jacksonville District. The project included three main tasks.
The first task was to construct and set six benchmarks meeting the requirements of Class “B” NGS Stability Standards. We then had to observe these six benchmarks, as well as eight existing control points, to establish accurate horizontal and vertical information on the monuments. Degrove used a jack-hammer to build the new benchmarks and did 24-hour static observations to establish the horizontal and vertical information.
The second task is the task that is ongoing. Degrove was tasked with recovering 48 benchmarks and obtaining a measurement from the measuring point of the monument to the top of water. Most of the benchmarks were submerged. All of these also had to be accessed with the aid of a helicopter.
The third task was vegetation monitoring. Degrove created sketches of each benchmark, showing the location of the surrounding vegetation.
The majority of the field work was completed by Degrove Senior Party Chief, Mark Coxwell (seen in pictures above and below).
Degrove Surveyors is in the process of surveying 600 hydraulic structures in the Lake Panasoffkee and Marshall Swamp watersheds. The survey is supporting efforts to develop a hydraulic model of the watershed for Marion County. The model is for the county’s Watershed Management Plan. Degrove is utilizing a combination of RTK GPS, robotic total stations, and digital levels to establish horizontal and vertical coordinates on the upstream and downstream sides of the 600 structures. The project is being managed by Degrove Vice President, Tom Tracz, and is being completed through the Gainesville office.
The tenth annual CH2M Hill Employee Sponsored Bikes-n-Bytes Charity Golf Tournament took place on October 28, 2010. Tom Tracz (pictured below), Randy Tompkins, and Will Pyle (pictured above) participated from Degrove. The Florida Crown Chapter of the Florida Surveying and Mapping Society sponsored a hole at the tournament.
All proceeds of the Bikes-n-Bytes Golf Tournament are used to purchase new bikes and helmets, as well as computers for underprivledged youth in the greater-Jacksonville community. The computers are donated to community centers in the Northeast Florida region. Over the past 10 years, the tournament has generated enough funds to purchase approximately 400 bikes and 75 computers.
The tournament was held at Deercreek Country Club in Jacksonville. Degrove thanks CH2M Hill for continuing to organize the event and support Jacksonville’s youth.
DeGrove Surveyors encourages all Floridians to Vote “NO” on Amendment 4 on November 2, 2010.
Amendment 4 is a “Vote on Everything” amendment proposed for Florida’s constitution. The amendment would require all exceptions to local comprehensive plans to be voted on in a full election (at the taxpayers’ expense), as opposed to being handled by those who are elected to make such decisions. Floridians would be forced to decide potentially hundreds of comprehensive plan exceptions every year. If passed, Amendment 4 would surely eliminate growth and development in Florida, and wreck an already struggling economy.
For more information on Amendment 4, please visit www.florida2010.org
Degrove’s Tyler Tracz, S.I.T., was elected to serve as Treasurer of the Florida Crown Chapter of the Florida Surveying and Mapping Society.
Tyler is pictured above (far right), with the other elected officers.
Degrove Surveyors was again well represented at the annual Florida Surveying and Mapping Society Conference in Naples, FL.
Degrove President, and former FSMS President, Ray Niles, attended the conference, along with Tom Tracz, Tyler Tracz, Will Pyle, and geomatics student intern David Lechner. The Conference always provides an enjoyable opportunity to reconnect with friends, and stay current on the happenings in the Society and in the surveying and mapping profession. We thank the FSMS employees, officers, members, presenters, guest speakers, and vendors for making 2010 another great conference.
Pictured above (left to right): Mary Niles, Ray Niles, Tyler Tracz, Will Pyle, Elizabeth Niles
Pictured below: Degrove employee, Tyler Tracz, greets U.S. Congressman Adam Putnam at the FSMS General Business Meeting. Congressman Putnam is currently running for Florida Commissioner of Agriculture, and Degrove gives him our full support..
Degrove recently completed a topographic survey of the Dead River in Eustis, FL for the St. Johns River Water Management District (SJRWMD). The Dead River flows between Lake Harris and Lake Eustis and runs underneath Highway 441. Degrove surveyed six cross-sectional lines that were specified by the District and totaled 8600’. The survey was completed through our Gainesville office.
The survey will enable SJRWMD to study the hydraulic characteristics and flows of the river. The data will also serve to populate the U.S. Army Corps of Engineers (ACOE) simulation program to model the water surface profiles and flows of the Dead River.
“Since the Dead River is the only natural flow way from Lake Harris to Lake Eustis, this information is critical for determining the minimum flow and level in the Harris chain-of-lakes, the historic lake stages in the Upper Ocklawaha River Basin, and the effects of discharge through Harris Bayou on the flow regime of the Dead River.” – SJRWMD
The topographic survey lines stretched across the Dead River from shoreline to shoreline including the cypress marsh that borders the river on each side. Control for the survey was established using RTK GPS and cross section lines were cut and laid out using total stations. A digital level and chain was employed where the swamps were too deep and overhead cover was too thick for other methods. In the open river, channel soundings were done with a conventional level rod equipped with a standard six inch circular plate attached to the bottom.
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