Aquatic Environmental Services braved the record snow event and cold weather to map a nine acre lake in Rome, GA on January 12, 2011. After delaying the job for two days we had to finally suck it up and get the job done before our schedule for the entire month became backed-up. The lake we mapped is located at Castle Farms in Rome, GA. We have been providing fisheries management services on this lack for several years now and have constantly battled with submersed grasses in the lake. This lake has a lot of water with depths of three feet or less and “gin” clear water. This creates prime habitat for aquatic weed growth because the sunlight can penetrate down to the lake bottom which allows the weeds to grow.
This lake is managed for quality bass fishing and more importantly aesthetics. Castle Farms provides company meetings, weddings, etc. overlooking the lake so any weed growth in the lake needs to be eliminated. Since the herbicides were not getting the job done and the grass carp escaped the lake during a flood, we determined the best solution is to dredge the lake to increase water depths. Increasing the water depths will decrease the amount of sunlight that reaches the pond bottom which will in turn decrease the amount of weed growth. But to accurately determine how much sediment needed to be dredge to achieve the proper depths, we needed to create a bathymetric map.
Common uses for these maps include: sedimentation control, volume calculation, recreation maps, habitat and ecology management, watershed management and awesome fishing maps. For this particular project, we wanted to find how much sediment needed to be removed to achieve a depth of four feet. With this data, we can the project the cost of dredging the lake instead of our client getting surprised with an enormous bill at the end of the dredging work.
Using a high end GPS unit connected to a depth finder, we are able to collect the data needed to create the bathymetric map. This system collects a GPS coordinate and water depth every second. To acquire the data needed to create the map, we simply drive around the lake while collecting data. In a lake with very little depth changes this is a very easy process but if the lake bottom has a lot of contours (ridges, channels, etc.) we have to make sure to collect enough data at these locations to accurately show theses changes on the map. Once all our data is collected, we send to our partner company The Mapping Network where they convert the data into the bathymetric map.
The pictures below show Castle Farms Lake. One shows the contour lines and the other is a 3-D representation of the lake.
Please contact Aquatic Environmental Services at 770-735-3523 or www.lakework.com if you are interested in lake mapping or any other fisheries management services.