Puslinch Lake

The lake is normally fed by surface runoff and underwater springs; there are no permanent inflow streams. Several ephemeral streams discharge into Mud Bay, however.[3] During high water conditions, the lake outflows into Puslinch Lake Creek, which is a part of the Grand River drainage basin. There is a channel connecting Puslinch Lake to Little Lake, located to the northeast. However, it is devoid of moving water, except for high water conditions.

The lake is relatively shallow, most of it being less than 2 m in depth; the maximum depth is approximately 5.5 m.[3] The deepest area corresponds to only 0.4% of the entire lake. Because of that, and due to very limited inflow and outflow, the lake actively undergoes the processes of eutrophication, with associated algal bloom, low oxygen level, and periodic fish kills. While these processes are natural, their rate is increased by anthropogenic factors, since a large portion of the lake's shoreline was modified from its original state to allow residential development. Increasing thickness of organic sediments resulted in the necessity to dredge the lake. Settling ponds were constructed nearby; however, they were quickly deemed inadequate. A new approach was then implemented, involving moving the dredged material into porous bags, which allowed water to be released back into the lake. The remaining dried material is intended for sale as topsoil enrichment.[1]

There are 16 species of fish present in the lake; some of them had been introduced. The lake supports a population of banded killifish, one of only a few known populations in the whole Grand River basin.[3]