Creston Valley Wildlife Management Area Water Control System Upgrade _ Leach Lake Water Control #2
Goals and Objectives
The Creston Valley Wildlife Management Area (CVWMA) is a 7000-ha “Ramsar” wetland located in southeastern British Columbia (www.crestonwildlife.ca). It was established in 1968 for wildlife conservation, management and development, in particular, as a waterfowl management area (Creston Valley Wildlife Act [RSBC 1996] CHAPTER 84). Over 35 water controls were put in place along with more than 25 km of dyke, to actively manage habitat for waterfowl and other wetland species.
Most water controls were put into the ground before the mid-1970s and have now surpassed their life expectancy. Six water controls have been replaced and two have been eliminated, since 2006, and we are now working on replacing another three in the next three years.
Water control #2 in Leach Lake is next on the priority list, and the actual water control structure has already been built and is waiting to be put into the ground. The control structure and all materials (e.g. High Density Polyethylene (HDPE) culvert) were purchased in 2009/2010, but could not be put in the ground due to a shortage of funding.
Water control #2, in the Leach Lake unit of the Creston Valley Wildlife Management Area, is vital to control and maintain the water level in unit 1, a 250-ha shallow freshwater wetland compartment. It is also critical for providing water to an additional 400 to 450 ha of wetland spread out into 7 compartments, i.e. water from unit 1 passes through water control #2, to unit #2, and subsequently to units #3, #4, #5, #6 and #7 through a network of water controls. Water controls (i.e. water control #2) are indispensable during wetland enhancement projects such as drawdown, as they allow isolating individual ponds.
The goal of this project is:
1) Continue managing water levels in all four main wetland compartments of the Leach Lake Unit to maintain the existing habitat utilized by waterfowl, species at risk, and other wetland related species.
February 2012-November 2012: Remove the failing existing metal water control structure by dewatering unit #1 and unit#2, building cofferdams at each extremities of the existing control structure to provide workable conditions, and digging out old water control structure and prepare ground for new structure.
October 2012-November 2012: Put the new, already built concrete water control structure into the ground, refill and compact ground to dyke elevation.
Benefits to Waterfowl, Wetlands-Associated Species, and/or Other Wildlife
The Units 1 to 4 are very productive wetland compartments and being able to control and maintain water in those units is necessary to continue providing annual staging, foraging and breeding habitat for tens of thousands of ducks, geese and swans during migration and the breeding season. Over 20 species of waterfowl can be regularly observed from April to October and the Leach Lake Unit also provides habitat for many federal and provincial species at risk such as western toad (Anaxyrus boreas), Short-eared Owl (Asio flammeus), western painted turtle (Chrysemys picta, Intermountain – Rocky Mountain population), northern leopard frog (Lithobates pipiens), grizzly bear (Ursus arctos), Amercian Bittern (Botaurus lentiginosus), American White Pelican (Pelecanus erythrorhyncos), Western Grebe (Aechmophorus occidentalis), etc. Mammals such as the
muskrat, beaver and river otter will also directly or indirectly benefits from the project as well as a few species of bats, and an unknown number of dragonflies and damselflies.
Relevance to Habitat Planning, Decision Making and/or Management
This project has immediate influence on conserving wetland habitat characteristics that benefit waterfowl and other wetland species, by allowing staff to regulate water levels in the Leach Lake Unit. A failure of the water control structure could potentially result in flooding waterfowl nests during the breeding season, or not being able to maintain adequate water levels at specific time of the year. Water control #2 allows to drawdown compartment #1 without having to drain compartment #2 and vice versa. Drawdowns are conducted fairly regularly to restore open water to vegetation ration (e.g. when cattail encroach on open water) in wetland compartments, within the CVWMA. In years of high snowpack, water controls can help
to flood upland areas adjacent to the wetland, thereby modifying the vegetation composition and/or slowing down woody vegetation encroachment.
This project is located approximately 11 km northwest of the town of Creston, in southeastern British Columbia. Water control #2 is located on dyke #2, which separates wetland compartment #1 and #2 of the Leach Lake Unit.
The Leach Lake unit is over 1,000 ha in size, and approximately 70% of it is productive wetland habitat (shallow freshwater marsh, seasonally flooded upland, black cottonwood riparian areas along rivers and channels, etc.). The wetland is located in the valley bottom between the Selkirk and Purcell Mountain Ranges and was originally a floodplain wetland. The wetland was diked in the early 1970 as a result of change in water regime due to damming on the Kootenay River.
For more information on this project, please contact Marc-Andre Beaucher, Area Manager/Chief Biologist, Creston Valley Wildlife Management Area, Creston, BC.