Aquatechnex pioneered the use of barrier curtain technologies to isolate portions of lake and river systems infested with invasive aquatic species at Shoecraft Lake in 2000.
Shoecraft Lake had heavy Eurasian Milfoil present in isolated bays on the lake. The problem was keeping a herbicide Sonar AS in contact with the plants for a long period of time as required without having to treat the entire lake water volume.
The solution was to place barrier curtains to cut off these areas from the rest of the lake, and treat the infested areas. These curtains contain a float on the water surface and a wall of impervious material through the water column to a weighted chain system that holds the curtain on the lake bottom. The results of this treatment were excellent, we were able to keep herbicide concentrations where needed inside the barrier areas and had no detect levels outside these barriers. Shoecraft Lake remained Eurasian Milfoil free for 11 years after this 2000 treatment. Recently new plants have invaded from an upstream lake, but one treatment eradicated this noxious weed from this system and kept it milfoil free for 11 years. (see Case Study ShoecraftCaseStudy1)
In more recent times, we have been using this same technology to target these invasive aquatic weeds in areas with high water exchange. Aquatic herbicides all have different contact exposure time requirements to be effective. In many cases large lake systems have currents present that can dilute these products rapidly. In other cases, river channels or reservoirs with infestations pose similar problems.
By isolating these zones from the surrounding lake or river channel, the water inside the barrier becomes stagnent and concentraion exposure times increase dramatically. As this happens, efficacy increases dramatically and lower levels of product are needed to deliver excellent results.