Natural Resources and Environmental Sciences Lake Fort Scott Bathymetric Survey Spring 2006 Natural Resources and Environmental Sciences Kansas State University

Natural Resources and Environmental Sciences

Lake Fort Scott Bathymetric Survey

Spring 2006Natural Resources and Environmental Sciences

Kansas State University

Kevin BergmanKyle Fitzgerald

Jud GladinJennifer Hancock

Tyler Pjesky



Outline• Introduction

– Purpose– Background Information– Bathymetric Survey

• Process and Approach– Contacts and Resources– Training– Conducting Survey

• Analysis– Assumptions– Volume Calculations

• Conclusions


Purpose

• Develop Map of Lake Bottom

• Estimate Lake’s Storage Capacity

• Determine Sedimentation Rate

Lake Fort Scott. www.giskansas.org


Background Information

• Lake Fort Scott constructed in 1958 to augment water supply

• Original capacity of 2.1 billion gallons or 6485 acre-feet.

• Water occasionally used from lake during dry years to maintain sufficient quality drinking water for city.

• Land use within watershed is primarily production agriculture (grassland)

• Shoreline property has been sub-divided into 141 lots for part-time and permanent year round residential housing


Bathymetric Survey

Bathymetric Survey: A survey of the bottom surface of a water body to produce a topographic map.

• Uses – Estimating water volumes– Mapping bottom surfaces of water

bodies for exploration


Single Beam Echo Sounder

A single-beam echo sounder produces soundings by transmitting short pulses of acoustic energy down towards the lakebed and detecting those pulses reflected. The depth under the vessel is then calculated from the 2-way travel time of pulses and the mean speed of sound over the water column

Image taken from pao.cnmoc.navy.mil/…/ indexunderwater.htm


Making Contacts and Acquiring Resources

• Kansas USGSLawrence, KS

• Hypack Inc.Middletown, CT

– Develops software for marine surveys

– Agreed to loan software for one month at no charge, $6,500 value

• Odum Hydrographic Systems Inc.Baton Rouge, LA

– Agreed to loan equipment at no charge

– One day of training at no charge, $10,000 - $15,000 value


Training

• Training in Baton Rouge, Louisiana

• Odom Hydrographic Systems Incorporated

• Detailed explanation of the survey process

• Hands-on-training on Mississippi River

Hydrotrac HT100 single beam echo sounder Hypack bathymetric survey software


Conducting Survey

• Equipment Requirements:– Boat

• 2000 Lund 1800 Fisherman

– Power Source • Generac 5550 Watt/8550 surge generator

– Survey Equipment • Hydrotrac HT100 single beam echo sounder• GPS receiver

– Analytical Software • Hypack

– Laptop • Dell Inspiron 300m

– Calibration Device • 8 pound anchor


Conducting Survey

• Preparation– Attach the transducer

– Mount GPS receiver


Conducting Survey

• Calibration– Building a calibrating device


Conducting SurveyDam

NORTH


Conducting Survey

Dam Location Cross Section Lines

Boundary Line


Analysis

• Assumptions

• Volume Calculations – Hypack– Notepad– Microsoft Excel– AutoCAD Land Desktop

• Map and Volume


Assumptions

• Minimum depth 2’

• Lake perimeter adjusted – Lake aerial image– Lake floor


Volume Calculations

• Hypack

• Notepad

• Microsoft Excel

• AutoCAD Land Desktop

2393474.48 1736804.91 840.302393543.38 1736881.02 843.002393618.11 1736951.12 841.602393700.28 1737010.30 839.702393787.47 1737060.83 837.40

1 2392920.09 1742689.33 844.92 2392940.53 1742683.83 843.23 2392960.56 1742682.78 842.14 2392981.52 1742685.28 841


Results

1957 2006 6,485 acre feet 5,980 acre feet

505 acre feet of sedimentation

• 7.8% capacity loss• 10.31 acre feet per year• 0.16% capacity loss per year


Conclusions

• The sedimentation rate of the lake may not be the major concern with quality water supply to the city.

• Adjacent land use may require better regulation.

• Rate is based on two points of data over 50 years apart which does not give an accurate indication of lake conditions.


Alternative Surveying Techniques

Hardware Alternatives

• Multi-beam Echo-sounder

• Fishfinder/Depth finder

• Manual depth recordings

Software Alternatives

• Hypack (for analysis and modeling)

• Trimble HYDROproTM


Service Learning Goals

• Contribution to Community

• Professional Development


Cost Comparison

• Project budget: $2000

• Project expenses: $1500– Software donated by Hypack Inc (actual cost = $6500)– Equipment donated by OHSI (actual rental cost = $95/day + shipping, etc)– Training donated by OHSI (actual cost = $800/day)– Personnel hours donated (actual consulting cost = $150/hr)

• Cost to hire a professional consultant to perform a similar survey: approximately $20,000

• Cost to City of Fort Scott– 2 nights at Best Western

• Learning Experience = Priceless


Acknowledgments

• City of Fort Scott

• Kansas Department of Health and Environment

• WaterLINK

• Odom Hydrographic Systems Inc.

• Hypack Inc.

Questions?

Documents

Natural Resources and Environmental Sciences Lake Fort Scott Bathymetric Survey Spring 2006 Natural Resources and Environmental Sciences Kansas State University