Muck & Sediment

Digestion of organic sediments not only eliminates them and reduces in-lake nutrients contained in them, but it is also far simpler, more cost-effective, and less messy than dredging.

Sophisticated bathymetric mapping allows the total volume of water in a water body to be calculated. The increase in water volume (after off-setting for changes in the water level) is due to the decrease in sediment and is, therefore, a measurement of sediment elimination by digestion of the organic fraction.

The data shows surveys conducted in October 2017 before commissioning the solution and in October 2018 after the program had been running for six months.

The water volume in October 2017 was 183 638m³ (148.88 acre-feet) and in October 2018 was 236 036m³ (191.36 acre-feet). This equates to an increase in water volume and reduction in sediment volume of 52 389m³ (42.48 acre-feet or 63 534 cubic yards). Had this volume of sediment been dredged out of the lake it would have required about 4 500 dump truck loads to haul it away.

Another way to depict sediment composition is shown in the graphic. Sediment shows as “soft” sediment high in organic content, or “hard” if the sand and rock at the bottom are exposed and not covered in soft organic sediment.

The gradient in the graphics runs from beige (soft) to red (hard). Therefore, what one wants to see is a reddening of the bottom composition which is quite apparent.

The pie chart depicts the sediment as being either soft, medium or hard and shows that soft has been almost completely eliminated, and hard has increased by about 200%.