How much water and where does it come from?
You may have noticed that American Lake does not have any large creeks flowing in or out of it. That's because most of American Lake is filled from thousands of springs of fresh water bubbling up from the gravel. These springs can often be felt as "cold spots" by swimmers. They can be seen on the bottom as clear, sandy areas free from vegetation. Fish often hang out around springs as the cold water is richer in oxygen than warm water.
History of the Weir
In the late 1800’s when people began building homes around American Lake, they built them on the bluffs because the lake would often flood the beaches and lower regions. As people began building on the shore, their homes would sometimes flood. After decades of looking for government support, a flood control standpipe and weir was constructed in 1959 by the Army Corps of Engineers that would prevent the lake from ever rising above 233’ above sea level. The “safe elevation” to prevent floods was 234.4’.
It allows the extra water to spill over a wooden debris barrier, constructed of 8’ boards stacked on edge, The water flows out into marshy Sequalichew Lake where there is a stand pipe that funnels the excess water under the road and out into Sequalichew Creek. From here it eventually flows to Puget Sound. The Fish and Game Department (now WDFW) placed an additional section behind the wall, so any fish that fell over the dam would be able to get back to the lake.
There were no flood events in the 50 plus years between dam installation and 2012 during which time the boards in the weir were left at the intended operational height of 233′. The weir worked very well and people had been confidently building around the lake shore.
The Army contracted Pierce County take care of the outfall, but not to . The fish structure behind the dam proved to be a trap for debris and other branches when the lake ran over, so it was eventually removed. Pierce County Surface Water Management is the entity that is charged with this responsibility today.
For a brief period of time, the County was removing boards in the dam at Labor Day and replacing them again at Mem
But in 2014, some “concerned people” sent a message to Pierce County. Although there is currently no known record of who these people were or what their concerns were, the County began removing some of the top boards in the weir so that water would flow over at a lower elevation. As late as 2021, the County was replacing the boards in time to catch the spring rains and the lake level was maintained at 233’. A few shoreline residents paddled over the weir and into Sequalichew lake at that time.
Since 2014 the county has manipulated the dam following no written operating practice.
The crews who control the dam height know what to do by following their “Rule of 3s”. Labor Day is a 3-day weekend, when they remove 3 boards. This limits the lake to a peak height of 231’ during the winter and spring rains. Memorial Day is the next 3-day weekend and it falls after the spring rains have flowed out of the lake. On this day they replace the 3 boards. Each summer the lake drops about 3’ during the dry season. So adding these extra boards has zero effect on raising the lake level.