| Willow Bunch Lake | |
| Location: | RM of Willow Bunch No. 42 and RM of Excel No. 71, |
| Pushpin Map: | Saskatchewan#Canada |
| Pushpin Map Caption: | Location in Saskatchewan |
| Coords: | 49.4582°N -105.5901°W |
| Type: | Salt lake |
| Basin Countries: |  Canada |
Willow Bunch Lake[1] is a salt lake in the southern region of the Canadian province of Saskatchewan. The lake is in the Big Muddy Valley in a semi-arid region called Palliser's Triangle. There are no communities nor public facilities at the lake. The nearest town is Willow Bunch at to the south and access is from Highway 36.[2] The entire lake and its shoreline has been designated an Important Bird Area (IBA) of Canada.
Willow Bunch Lake is shallow salt lake with a surface area of about .[3] It sits in the Big Muddy Valley, which was formed over 12,000 years ago near the end of the last ice age when a glacial lake outburst flood occurred from a pre-historic glacial lake located at present-day Old Wives Lake.[4] In the summer, extensive mudflats develop at the east and west ends of the lake providing habitat for a variety of species, including the piping plover.
The entirety of Willow Bunch Lake is part of the Willow Bunch Lake (SK 020) Important Bird Area (IBA) of Canada.[5] The IBA, which totals, is important to the piping plover as it has one of the three largest breeding concentrations on the Canadian Prairies. The other two areas are Chaplin Lake (SK 033) and Quill Lakes SK 002. The provincial Wildlife Habitat Protection Act designated the entire Willow Bunch Lake basin as a critical piping plover habitat and the lake's shoreline up to the high water mark is protected from development. The population and breeding success of the piping plover depends largely on lake water levels. Being in a semi-arid landscape with no major inflows, Willow Bunch Lake is subject to widely fluctuating water levels and this becomes one of the main threats to the long-term success of the birds.[6]