Flood mitigation projects worth $120M underway
The rush of water through Windsor area streets and into basements during heavy rainstorms in August 2017 and September 2016 has local municipalities pouring millions of dollars into improving sewer systems and overland water flows.
There are over $120 million in construction projects underway or in the planning stages. Also in the works are plans to harmonize regulations and standards, and better co-ordinate approaches to battling the threat of flooding. “There’s an administrative energy being put forward focused on infrastructure assessment, maintenance and upgrades,” said Tim Byrne, director of watershed management for the Essex Regional Conservation Authority (ERCA). “The floods have definitely created more of a focus on the issue.” ERCA’s rain gauge in South Windsor recorded nearly 300 millimetres of rainfall in 24 hours last Aug. 28-29.
“2016 was terrible, but after 2017 we felt (flooding) was out of our control,” said Windsor Mayor Drew Dilkens. “We came up with
an eight-point plan to try and do something. It’s going to take 10 years, but this plan is going to get done.”
The municipalities hit hardest by the two major floods — Windsor, Tecumseh, LaSalle and Lakeshore — are all working on master sewage and storm water plans that should be completed within a year.
ERCA is overseeing a harmonizing of development and planning standards in the area to deal with the growing threat of overland flooding.
All four municipalities are doing computer and topography modelling to help them understand what overland water will do when it rains heavily. The models can show how water behaves in varying intensities and durations.
In all, about 11,000 area homes reported flooding from the two events.
Windsor has already announced a nearly $90-million plan focused heavily in the Riverside area. It includes sewer replacements, upgrades to pumping stations, sewer and rebuilding roads. The city is already working on the Lennon Drain in South Windsor and the Riverside Vista project, both of which will aid storm water management.
Tecumseh has a $30.3-million plan in place to cover over the Manning Road ditches and improve sewers and pump capacity along Riverside Drive. LaSalle is focusing on a $3-million project to turn a park and sports recreational area into a dry pond in the Heritage Estates and Oliver Farm areas. That area flooded two years ago during a localized storm unrelated to the Sept. 29, 2016 flood.
The town is also working to improve its municipal drains and overland flow measures. Lakeshore’s priorities are making improvements in its sewers and pump capacity in the western end of the town that got hit hard in 2016 and 2017 and to expand its waste water treatment plan. Of the four municipalities, Windsor is the only one that still has areas with combined sanitary and storm sewers. About one third of the city’s 1,800 kilometres of sewers are combined. “Historically, development took place in a random fashion,” said Byrne. “Now we’re faced with moving to put in place a planning process that’s more intricate and sophisticated. We’re trying to compensate for a rudimentary process that goes back to the turn of the previous century.”
Byrne added that in some areas the shoreline has become built up to the point that water run-off can’t escape into the lakes. The new reality is municipalities have to defend themselves against flooding coming from the sky as well as from the lakes and rivers due to a changing climate. “The lakes are near record levels and we’re concerned one good rain with the wind coming from the right direction and it could be really bad,” said City of Windsor engineer Mark Winterton. “We’re flat, surrounded by water and have 100-year-old sewers. I have a lot to worry about.”
After a century of municipalities going their own way on development and flood control, the solution is going to require a coordinated effort.
The towns of Tecumseh and LaSalle are part of Windsor’s water system, which means any improvements by one are beneficial to all. “By making flood mitigation improvements, not only do we prevent flooding for our townsfolk, we also save money by sending less water to Windsor to be treated,” said Tecumseh Mayor Gary McNamara.
LaSalle, which has relatively new infrastructure, has avoided major flooding recently, other
The lakes are near record levels and we’re concerned one good rain with the wind coming from the right direction and it could be really bad.
than some overland water at the Turkey Creek in 2017, said Mayor Ken Antaya. “That was water pushing through from South Windsor. It just couldn’t get out to the river fast enough.”
Nelson Cavacas, Lakeshore’s director of engineering and infrastructure, said the intensity, frequency and duration of rainfalls requires changes to planning standards.
“I think we need to look especially at what we’re doing on the storm water side,” Cavacas said. “We can only redirect water and build up sewers to certain point.” All agree a major piece of solving this puzzle lies in keeping water in the ground, holding and controlling its flow and redirecting it away from the sewer system. “People wondered about (Tecumseh) spending $15 million to buy Lakewood Park, but that park plays an important role in our flood mitigation strategy,” McNamara said. “Underneath it we have a new reservoir, big sanitary sewers. We built a storm channel and a pumping station. Including buying the land, we’ve put $50 million in that park.”
The biggest challenge for Tecumseh is controlling and redirecting water that naturally wants to flow to the lake. The park is again central to the town’s proposed $30.3-million plan.
“The next phase is to make the park a dry pond,” said Phil Bartnik, Tecumseh’s director of public works and environmental services. “The storm channel can overflow and the park will hold it. Better a wet park for a few days than water in people’s basements.” Towns are increasingly using parks, sports fields and existing infrastructure in their flood mitigation plans.
When Lakeshore redid St. Peter’s Street in Belle River recently, the town regraded the road to carry water straight into the Belle River. Roads are engineered to hold at least 30 centimetres of water. “We’re working with ERCA to design overland water flows,” Cavacas said. “We’re using roads to do that as we rebuild them or put in new ones.” Another example of innovative use of existing infrastructure is Windsor’s development on the site of the old Tecumseh water treatment plant at Martinique Avenue and Riverside Drive. Winterton designed the development for townhouses and 19 single-family homes. He addressed area residents’ concerns that the new development would overload the sewer system by using the old pumping station’s intake pipe as the storm water sewer. The storm water from the development won’t enter Windsor’s system but instead will drain off directly into Lake St. Clair.
“We have to think differently,” Winterton said. “We have to try and keep water out of our sewers rather than build bigger ones.” All four municipalities are inspecting and repairing their existing sewers for leaks or cracks. The seepage of water into sanitary sewers is a significant source of overloading the system.
Last spring, such seepage forced Lakeshore to ask residents in the town’s western end to not use household water for about an eight-hour period while the pump stations cleared out the backlog from a rainfall.
Another source of unwanted storm water in sanitary sewers are
downspouts directly connected to the system.
Local municipalities are also trying to eliminate manhole covers as a source of leakage. Towns are installing plastic catch basins underneath the manhole covers to catch water so the overflow stays on the roads. Tecumseh has adopted LaSalle’s longtime policy of requiring sewer ejection systems for plumbing in the basements of homes. All basement plumbing is connected to the ejection system, which is powered by an electric pump, and the waste water is pumped out of the basement and into the sanitary sewer system. It’s a self-contained system that doesn’t rely on gravity to drain waste water, thus preventing the chance of sewage backups. Tecumseh is requiring all new builds to install ejector systems while Lakeshore is doing it on a case-by-by case for new developments.
A potentially more controversial idea being studied by Windsor is the introduction of a storm water fee.
The fee is aimed at providing incentives to use building materials that allow water to pass through into the ground, construct green roofs and use rain barrels as water collectors.
“We have to try and recharge the ground with water,” Winterton said.
Byrne said the issue of how much land is now covered by impervious material needs to addressed. He said planners have traditionally used an average of 50 to 60 per cent as the estimated coverage of a residential lot by impervious materials.
“We’re now seeing 70 to 80 per cent coverage,” Byrne said. “Houses are bigger, people have big patios, outdoor kitchens, sheds and pools. We have to respond to this to create design standards to address that.”
Municipal officials stressed their efforts will be limited in success unless residents also take responsibility to do what they can to flood proof their homes.
All four municipalities are offering subsidized programs to encourage downspout disconnections, install sump pumps and backflow valves, and camera inspection of private sewer lines. Both Windsor and Tecumseh are considering making downspout disconnections mandatory. Tecumseh is also considering making sump pump wells mandatory. “Homeowners have a responsibility to protect their homes,” McNamara said. “We’ll help, but the big lesson has been ‘don’t be complacent.’”