| The height of the water to be contained by the AquaDam® is the most important criteria in selecting the proper AquaDam® size. Consider a diversion channel installation. For a diversion channel of approximately the same width as the stream, a good rule of thumb for determining the water height after diversion is: Add 1) Max Water Depth along Site, 2) Average Water Depth along the Site and 3) Difference in elevation between the installation and the divert water sites. These three numbers equal the height of the water that will be found at the installation after the AquaDam® is installed and the water is flowing through the diversion channel. Figure 1. The height of the water to be controlled by the AquaDam® is related to the maximum depth of water at the installation site and the difference in the water levels between the installation site and the diversion point.
 How does Water Velocity influence the size?
When an AquaDam® is used to stem a water flow, some consideration must also be given to the velocity of the water running around the end of the AquaDam® during installation. When the water flow is being pinched off during installation, the water velocity will increase and depending on the firmness of the stream/river bed that the AquaDam® is being laid over; may cause some undercutting and erosion around the end of the AquaDam® as it is being installed. This would result in an increase in the height of the water to be controlled and should be considered in the above diagram when determining the correct size AquaDam®. Water velocity will play an important part in the installation of an AquaDam®. For example, during installation a AquaDam® has to be filled to a higher level than the water to be contained to prevent it from washing down stream. Once the AquaDam® is installed in flowing water, the water will pool in front of it and increase in height. Flow near the AquaDam® will be terminated and sent down the diversion channel. Are there limitations related to the flow periods?
As long as the maximum water depth to be controlled during the life of the project does not exceed the maximum recommended water depth for the size AquaDam® being installed it will remain stable for the duration of the project. In the event of an unexpected increase in the water level being controlled, the AquaDam® can be removed in a few hours. This causes little environmental impact and the AquaDam® can then be reinstalled after the water levels return to normal. A second option would be to increase the height of the installed AquaDam® by pumping more water into the structure and temporarily super-inflating it. For example, a 3-ft-high AquaDam® could be super-inflated to 4-ft-high under the right conditions. Next, stop the dewatering process to allow water to equalize on both sides of the AquaDam® if possible. |