What the heck’s happening at Brewer Pond??

By Carol Macleod

Those of you who have been around a while may remember fondly the swimming hole on the Rideau at Brewer Park. It has been closed for several decades, being slowly reclaimed by cattails. Over the years the Environmental Committee of Ottawa South (ECOS) rooted out invasive species and planted native shrubbery around its shore. It also developed a signed interpretive trail. Recently you may have noticed blue fencing around the pond as you cycle south on Bronson past Sunnyside. What’s going on?

THE PROBLEM WITH BREWER POND

Each spring, Brewer Pond is inundated by Rideau floodwaters. As water levels drop, trapped fish die in the landlocked pond. The bottom of the pond is 1.5 metres above the Rideau’s bottom, so not much water stays in the pond. What’s left becomes almost stagnant. Tests show that the oxygen level in the pond is so low that it cannot sustain most aquatic life, including amphibians, fish and plants. It’s definitely not a good place for fish to lay eggs or for minnows to feed or overwinter. It doesn’t even support a healthy frog or plant population. Moreover, there’s not much wetland suitable for fish habitat on the shores of the lower Rideau.

BREWER POND RESTORATION: THE SOLUTION

The answer? Create 16,000 square metres of suitable fish habitat on the lower Rideau River by reconnecting the old swimming hole to the river by a large culvert, and adding brush and other underwater hiding spots to make the pond more fish friendly. The area around the old change house will be somewhat altered. Although there will be a lot of work up-front, soon only close observers and anglers will notice! It’s a project that offers an opportunity to increase riverside habitat for the 40-odd species of fish that live in the Rideau system.

HOW THE PROJECT CAME ABOUT

How did this project, long the dream of ECOS, come about? Over more than a decade several like-minded organizations including ECOS, the Rideau Valley Conservation Authority (RVCA), the Ontario Ministry of Natural Resources (MNR), the federal Department of Fisheries and Oceans (DFO), the city of Ottawa, Muskies Canada and more recently Carleton University, developed a plan to return the pond to a natural wetland condition, improve connection to the Rideau River and enhance sport fishing on this part of the Rideau. Muskie Canada’s (www.muskiescanada.ca) interest in the project flowed from its mandate to protect muskellunge, an iconic fighting sport fish indigenous to the Rideau system. The club conducts research and manages muskies to enhance the sport fishery, and carries out projects designed to raise public awareness of the muskellunge.

The problem, as always, was money. How could such a costly project be funded? The Department of Fisheries and Oceans requires developers to compensate when their developments destroy fish habitat. The RVCA remembered discussions about Brewer Pond, and has experience with similar but smaller restoration projects. The Brewer project is still being refined by consultants from Minto and Richcraft, with input from the local community. The estimated budget is $1 million.

WHAT WILL THE PROJECT INVOLVE?

As the RVCA describes it, the proposed restoration project is to reconnect this pond on the north shore of the Rideau River adjacent to the Brewer sports field east of the Dunbar Bridge and create a wetland embayment (a wetland pocket). So far the project involves excavating the pond to create three levels ranging from a depth of 4.5 meters to a one-metre shallow shelf. Brush and logs will be placed in the excavated pond to serve as shelter for fish and frog eggs and hiding spots for minnows. Channels will be dug to allow the Rideau River to flow freely through the pond.

On shore, some shrubs and trees are being dug up for replanting; others will be replaced, and more trees will be added. The top several inches of soil from the surrounding shoreline will be removed and stored on site because it is full of seeds from plants already established there. This soil will be spread back on the shoreline when the excavation work is done. The RVCA sources fish and plant material locally where possible. Trees come from the Ferguson Forest Centre in Kemptville, which also sells tree and shrub seedlings to private landowners (see http://www.seedlingnursery.com/). Finding local wetland plants is a taller order. They currently come from southwestern Ontario but a major supplier has just closed.

BENEFITS

At Brewer the RVCA believes the benefits of a reconnected pond for the Rideau watershed to be manifold. The pond will allow fish species year-round access into the pond and out to the Rideau River, by allowing water to flow from the river through the pond and back to the river. It will raise the level of oxygen in the water to a healthy level to alleviate fish kills believed to be related to lack of oxygen in the pond in the winter and summer months. The deeper and shallower water levels in the pond will create conditions suitable for more diverse plant material both below and above surface. The restored wetland will provide good new spawning, nursery, rearing and food supply habitat for the fish community of the adjacent reach of the Rideau River. It will provide new and enhanced winter and summer refuge areas for fish. It should increase biodiversity. Finally, it will improve water quality the length of the lower Rideau River as a result of the wetland enhancement.

The RVCA also hopes the project will benefit the community. The current uses of Brewer Park will not change. Sports teams continue to use the change house, so it will stay. ECOS educational signage will be retained and signs will be added to describe the project and its social and ecological benefits to the lower Rideau watershed. The project in an inner city neighbourhood is a pilot in private/public partnership. More trees will be planted around the pond, contributing to Ottawa’s 20 per cent forest cover target. The Ottawa South Community Association and ECOS will continue to use the site for environmental events focused on the restoration activities such as fish appreciation and biodiversity, and it will provide inner city anglers with exciting fishing opportunities.

The third local partner is Carleton University. The Brewer project simultaneously provides Carleton students with educational opportunities, research questions and lessons in working with community groups. It has become a field site for several Carleton programs. Environmental Science students have analyzed sediment cores, assessed the vegetation community, and collected water quality parameters in the pre-monitoring phase of the project to enhance RVCA data. For over a year, students in the Fish Ecology and Conservation Physiology Lab have radio tracked northern pike and muskellunge in the river adjacent to the pond, a tool commonly used to provide baseline movement on the spatial and seasonal ecology fish species. The lab will continue to track these species during construction and for several years thereafter to see how they use the new habitat. If effective, the approach used at Brewer could be adopted elsewhere for these species. The project has been advanced as an example of how to plan and implement a habitat creation project. Students are included in meetings with project planners. The collaboration among levels of government, developers, and environmental and community organizations is considered to be a pioneer model that may become the norm for future habitat restoration projects.

WHAT WILL HAPPEN NEXT?

This month and next, fencing will be erected to allow the work to be done safely and efficiently. Any remaining aquatic species will be removed and relocated to the Rideau River. The pond will then be dewatered. After the pond level is brought down substantially, excavation will begin. The pond will be shaped into the three zones of varying depths, and structures such as basking logs, sweeper trees and inverted stumps will be placed in it. The site will be stabilized using erosion control blankets and the new banks will be seeded. It will take approximately eight weeks, depending on weather, to complete the work and stabilize the site for winter and spring freshet.

The RVCA will evaluate the project for at least five years. Each year the RVCA will look at how the fish are using the new habitat. They will assess the quality of the vegetation (how well it is growing), and plants will be replaced as needed. They will also check the stability of the new water levels to see whether the culverts are silting up and whether there is silting or settling in the pond proper. Carleton University researchers will collect fish from the pond to examine their health and will put new fish into the ponds to see how they do. We look forward to watching the implementation of this unique project on our doorstep.

Carol Macleod is co-chair of the Glebe Community Association Environment Committee and an avid enthusiast of the natural world.