It’s fairly common to use turbidity curtains where the depth varies across the containment area - not many rivers have a flat bottom, after all. In all but the gentlest of type 1 situations, you want the bottom of the curtain to be about 1 foot above the floor of the waterway, but directly touching the bottom risks both damage to your curtain and ineffective containment. For this reason, “splitting the difference” and using an average depth won’t work. Instead, you’ll need to make some adjustments to your curtain design.
One way to make adjustments is to request different depths for different segments of your curtain. When the segments are installed in the prescribed order, the profile of the curtain will approximately match the bottom of the waterway. BTL Liners can quickly fabricate custom curtains with varying lengths, which will arrive at your site clearly labeled for easy, quick installation. Another option is the addition of reefing, or furling lines to your curtain segments. Installed during fabrication, these lines allow you to manually adjust the depth of each curtain segment while it is in place (from a boat, for example). This system also permits accommodation of more significant changes in the profile of the bed, since you can simply raise or lower the depth of the curtain as needed. If you’ve got a situation where changes in depth are due to tidal action rather than profile of the river bed, you may opt for a tidal compensator. This equipment actively moves up and down with the changing water level, raising and lowering the bottom of the curtain as it goes.
