Hood Canal is in Washington and connects to Puget Sound. Anthropogenic water and noise pollution from industry are problems. Kip Taylor from Parkland, a former major in the Marines and for three decades has seen this. Richard (Rick) Hicks from Seattle advertised on Craigslist.org for CAD and GIS services and Mr. Taylor answered the ad and we got together to design a fish ladder for use in the canal. For the pollution issue, and oxygenation tunnel for low dissolved oxygen areas from Puget Sound to Hood Canal the designs were put into CAD drawings documented for mapping placement. See the bottom of the page for drawings. View or download the Sea Grant detailed article on the problem below.
To support increased oxygen to acceptable levels and one approach is to add an oxygenation/aeration tunnel from Puget Sound to Hood Canal underground to Case Inlet/North Bay (fig. 3, 4 & 5). Alternate configurations are possible with the figures and links below. A major concern is keeping the water passage free from debris including silt and sand with no way to know without scaled testing.
Tidal high differences between the Puget Sound inflow end and Hood Canal outlet fluctuate meaning aerated water out of valves passing through the tunnel is now about 2mg/L without modification. Tides are oxygenated more from Puget Sound due to the landscape.
Outdated data by the UW (Newton et al) says the dissolved oxygen is about half of what healthy waters should be. The tunnel addition for O2 level increase is not quantifiable at this stage of development. Thoughts are the venturi system to have a bubblator-type (venturisysdetails download below) to add air, or air pump(s) to increase O2.
Another concept from Kip is an innovation in fish ladder design (fig 1). Stacks of these ladders are needed for fish to climb and to get to the spillways or the top of dams.
Mr. Taylor saw the deterioration for about thirty years. Once the canal was thriving with salmonid species is now a far cry from that due to fishing, netting, and water pollution. I recall growing up my father Arlie (Bud) eating live oysters from the beaches in Hood Canal because he owned property near the beach.
Lake Cushman Dam & Lake Kokanee Dam (a.k.a. Cushman 1 & 2) are potential locations however, no readable/usable engineering drawings from the survey gallery are available online:(https://www.loc.gov/resource/hhh.wa0270.photos/?sp=1&st=gallery).
Prior to Kip Taylor passing away, the concept was different using a single venturi nozzle at the outlet. Those passive-plan drawings were kept and drawing scans are available from the links below.