1. Field of the Invention
The present invention relates to a water body cleaner, and, more particularly, to a water body cleaner with a sediment dredging head.
2. Description of the Related Art
Sedimentation of streams and lakes is listed by EPA as one of the most damaging pollutants of US waterways. Sedimentation chokes otherwise native coarse gravel bottoms such that the streams are no longer supportive of a diversity of native aquatic species, while also diminishing habitat for fisheries. The polluting fine sediments have entered our streams and lakes from a combination of unnatural sources, including poor agricultural practices causing wide spread soil erosion and run off, run off from streets and man-made surfaces, run off from disturbed construction sites, run off from increased deforestation, and run off from both urban and rural roads and highways.
In the last few decades, much experimentation and efforts have been made to restore streams by removing the undesirable fine sediments and restoring a relatively clean coarse gravel and cobble stream bed.
One such device is commercially sold by Streamside Systems, LLC as the Sand Wand™, which uses the unnatural method of a jetting system that drives water into the bottom and disrupts the structure to dislodge sediments into a slurry, which is then removed with a separate suctioning system. The Sand Wand is a dual system, which requires two separate heads, two sets of hose lines and two separate pumping systems. The Sand Wand's methodology is also disruptive to the stream bed, and relatively cumbersome to operate.
Shear stress is the ability of liquid flows to entrain (suspend) sediments and transport that mixed flow of liquid and sediment (slurry). Sediment particles in the streambed become suspended into the flows when the resistance to shear is exceeded, or what is known as the critical shear stress. The greater the shear stress the greater the particle that can be transported. Shear stress in a natural stream is affected by many factors, including, change in elevation, configuration of the channel, volume of flows, and size of sediments within the stream bed. Where shear stress increases, the capacity to mobilize and transport sediment increases in both volume and particle size. Where shear stress decreases the capacity to mobilize and transport sediment decreases in both volume and particle size.
Unfortunately, many US streams have been overwhelmed with fine sediment pollution to the point that those steams no longer have the capacity to create critical shear stress forces sufficient to mobilize and remove sediment pollution, leaving the stream habitats permanently degraded and without the necessary coarse gravel and cobble bottom conditions needed to support a healthy stream ecology.
What is needed in the art is a simpler system for removing undesirable sediment from a stream or other water body with less disruption to the stream or water body's bottom conditions.