The low head dams in and around the park, Bosher’s Dam and Z-Dam, are extremely dangerous and should be avoided at all times while recreating on the James. You must use the available portages to bypass these dams. For more information on why low-head dams are dangerous please watch this video.
River strainers are created by obstructions – naturally formed or man-made objects – that allow water to pass through but “catch” larger objects, pinning them in place. In essence, they will strain the river of debris, boats, animals, and people, by “filtering” the water through the gaps in the obstruction – hence the name. They can be a dangerous feature of a river or a stream because they can cause you to become trapped against the blockage. Strainers are extremely hazardous and must be avoided.