In the early years of the Garden there was a small open pool at the north end of the wetland, within the current Garden space. The small pool was created by Eloise Butler when she built an earthen dam. Eloise describes her placement of the dam. “A tiny stream threaded the bog and emerged into a depressed area of slimy ooze flanked by low banks. A dam was constructed that converted the depression into a lovely pool …..” (The Wild Botanic Garden - Early History by Eloise Butler). By the time an article about the Garden was published in The Bellman in 1913, the dam was described as covered with vegetation as though it had always been there, so it must have been put in right around 1907 when the area was set aside as a botanic garden.
In the north meadow, north of the current Garden space, the large Mallard Pool was created by Eloise Butler in 1932. By late 1939 the Mallard Pool area was being abandoned by curator Martha Crone. Details on that pool are in the Mallard Pool article.
Now we concern ourselves with what happened in the existing Garden wetland space. The existing small pool at the north end of the Garden was too shady for sun loving aquatic plants, which is why Eloise Butler wanted the larger pool in the north meadow. Plus, most of the 1930s were dry years and wetland water fluctuated. So, to provide more water in 1939 curator Martha Crone had a spring tapped on the west shore of that open pool in the wetland by the dam and it supplied a good flow of water. In later years she wanted visitors to have a close-up view of aquatic plants that were in and by the pool, so a trail through the center of the wetland was added in 1946. The trail was a necessary step for the next project Martha wanted to do. To rectify the problem of shadiness, she had two more pools dug out in 1947. There were now three in total including the original wetland pool by the dam. In 1948 she had the two new pools enlarged and in these she planted aquatic plants. One of the pools is shown in the photo above just after it was enlarged in 1948.
Below: This photo from May 6, 1949 shows the same new pool that had been enlarged the year before. These pools in the wetland subsequently silted in and swamp grass took over and the pools had to excavated several times, to preserve the open water. Gardener Ken Avery and assistant Ed Bruckelmyer did the first excavation in 1961, removing swamp grass and digging out to a depth of 18 inches. The pools were not connected and if rainfall was not sufficient, the pools would be filled with a hose run from the city water supply in the Upland Garden, one pool at a time. So when Ken and Ed dug out the pools they created a channel from one to the other so that filling one would cause the others to fill also. By 1965 the pools were only 6 inches deep so Ken dug them out again, this time to a depth of two feet. By 1979 the pool channel was silted in and had to be dug out once more.
In the photo below taken on May 27, 1950, we see what was called "pool #3," two years after enlargement, with vegetation covering all scars.
Below: Here is another view of the marsh taken on the same day, May 27, 1950, from a different angle, with the same pool visible.
Below, in a photo from June 23, 2008, we see the vegetation of the wetland today. It was such a chore to keep the pools open that after digging them out in 1979 they were left to silt in. Without open water, a number of the water plants that Eloise Butler and Martha Crone had set out can no longer grow. There can be standing water in the wetland in the spring and during very rainy periods, but not open pools.
Below, in a photo from April 2008, the topography of the wetland area is clearly visible. The perspective is from the opposite direction from the photo above. The path follows that established by Martha Crone in 1946. The depressed area behind the Red Osier Dogwood may be the site of one of Martha Crone's pools.
Below, the same area as seen above but from a closer position. The black path marker post is a reference point. May 2018.
Below: In the spring the lack of open water creates a perfect environment for Marsh Marigold (Caltha palustris ) which is prolific in the wetland in early May.
Below: We do not have any photos of the old pool by the outlet dam, but here is a photo from recent times of the remnant of that pool. This pool area in the Garden may be entitled to take on the old "Mallard Pool" name as these Mallards find it of interest. They were found scouting out the pool area on April 29, 2008. The current rock outcrop dam is visible at the top of the photo and is in about the same position as all the previous dams going back all the way to Eloise Butler's earthen dam. The pool was dredged in 1992 but has silted in once more.
For more information on the wetland at Eloise Butler Wildflower Garden see our article on "Wetland History"