Oshawa Second Marsh makeover postponed

Oshawa, Ont. – A collaborative makeover of the Oshawa Second Marsh – one of the last remaining windows to the natural wonders of wetlands in the Greater Toronto Area’s backyard – to lower water levels and kick start biological activity within the wetland has been postponed.

In the spring, the City of Oshawa, Central Lake Ontario Conservation Authority, Friends of Second Marsh and Ducks Unlimited Canada (DUC) joined forces to give nature a helping hand. The partners began a Second Marsh drawdown project to help ensure that the marsh continues to function as a healthy wetland that supports a diverse wildlife community.

By gradually drawing down marsh water levels using an on-site pumping system, new growth of plants that provide essential food and cover for wildlife would be encouraged. This biological management technique of lowering water levels was to be temporary; and in September, gradual re-flooding would bring back typical fall water levels, improving water quality and attracting local and migrating waterfowl, shorebirds, raptors, songbirds and other wildlife to feed and rest.

However, a combination of pumping challenges in the spring and strong storm events in June made proceeding with the project this season impossible.

“The partners and volunteers worked tirelessly to overcome the pumping challenges we faced early in the process,” says Dave McLachlin, biologist and conservation specialist for DUC. “Thanks to their diligent monitoring and reporting, progress was being made, but when we were hit with heavy rainfall throughout June, including a severe storm towards the end of the month, that was the tipping point. We were simply unable to continue the draw down this season.”

According to the team at Central Lake Ontario Conservation Authority, the June 2015 rainfall amounts were well above historical averages, with 76% of the average monthly precipitation falling overnight on June 22.

During this significant rain event, partners learned that infrastructure installed back in 2002, designed to manage flood waters from major storm events such as this, had proven successful.

“Wetlands function as important tools in the control of water levels,” explains Heather Brooks, Director, Watershed Planning & Natural Heritage for Central Lake Ontario Conservation Authority. “They can store significant quantities of water during rain events and slowly release water during dry periods. In this case, the existing infrastructure and Second Marsh worked together to help redirect high water levels and prevent overtopping of the banks downstream”.

Before the project was put on hold, benefits to wildlife were already being observed, explains Friends of Second Marsh Executive Director Brian Brasier: “This year, Second Marsh saw record numbers of Little Gulls during their annual migration through southern Ontario followed by an impressive variety of arctic-breeding shorebirds stopping at the marsh to feed on the exposed mudflats.”

For more information, visit oshawa.ca/secondmarsh.