The following links may be helpful in exploring Lake Union and Portage Bay:
How to Find Lake Water Quality Information
By Dave Galvin, a local houseboater who works in the field.
Lake Union Virtual Museum
Short videos about Lake Union and Portage Bay.
Includes the Lake Stewardship Program. Volunteer to help King County monitor lake water quality.
North American Lake Management Society, a professional organization site with links to many sources for lakes information.
"The Health of Lake Union," an article from The Seattle Press.
http://www.nwd-wc.usace.army.mil/nws/hh/basins/data.html?lkw+bths (real time and last month)
Army Corps of Engineers lake level charts.
King County swimming beach monitoring data.
The Portage Bay Coalition for Clean Water Houseboats and Milfoil
Milfoil and other invasive plants.
(2002) Lake Union Sediment quality.
Sediment quality near Gas Works Park. (2003)
Combined Sewer Overflow program.