Watersheds & Marsh Water Quality
Cootes Paradise Marsh receives water from 17 different streams while Grindstone Marsh receives water from 9 different streams. These flow from neighbourhoods, parking lots, agricultural lands and natural areas covering 270 km2 and 89 km2 respectively. The health of these marshes reflects the conditions of the upstream communities.
Recovery of water quality to that typical of natural Ontario conditions is a basic goal for the restoration of the marshes but requires each property on the land to take responsibility for water runoff. Few inflowing creeks are restored to clean water. Chedoke Creek watershed flowing from West Hamilton remains substantially polluted. It enters Cootes Paradise Marsh in the southeast corner along the Desjardin Trail at Princess Point access area. Chedoke Creeks sewer system is regularly overloaded with water from the urban landscape during moderate to larger rainstorms and spills to the creek.
Many projects in recent decades including the exclusion of carp, improvements to agricultural lands, and establishment of several urban C.S.O. (Combined Sewer Overflow) tanks have resulted in a much healthier marsh and much of Cootes Paradise Marsh now has fair water quality, and a some interior areas have excellent water quality (CCME Guidelines).
Water quality monitoring data results are available through Great Lakes Datastream’s interactive map.
Watershed Report Cards
Watershed report cards are reports on local watershed conditions using a standardized set of indicators and evaluation, focusing on surface water quality, groundwater quality and forest cover.
Chedoke Creek Remediation
In July 2018, the City of Hamilton informed the public that the largest of the Combined Sewer Overflow tanks within the City had malfunctioned. In November 2019, it was clarified that this tank had been malfunctioning since 2014, with 2018 including an additional malfunction. The effect was the discharged of 24-billion litres of sewage and urban stormwater spill into Chedoke Creek and subsequently Cootes Paradise Marsh over a period of four years. Royal Botanical Gardens publicly voiced our concerns, while at the same time providing ongoing environmental condition monitoring updates for Cootes Paradise to Hamilton Harbour Remedial Action Plan partners.
Following a Provincial Order, the city worked with the Ministry of the Environment, Conservation and Parks (MECP) to investigate the incident and plan for remediation efforts in the Creek and Cootes Paradise. The City then submit workplans to the MECP that defined remediation/mitigation method to offset damage from the spill and the added nutrient loading to Chedoke Creek, Cootes Paradise Marsh and the Western Hamilton Harbour Area.
The City of Hamilton has created an information resources map to help understand the many elements of restoring water quality in Chedoke Creek watershed to help create a healthy environment at the waterfront in Cootes Paradise.
The overview to all the elements is the Chedoke Creek Watershed Improvement Framework, created by the City of Hamilton in 2021 in collaboration with stakeholders including Royal Botanical Gardens. It includes many strategic projects to reverse the damage of a century of note valuing water and was spurred to action following a 4 years spill of the largest CSO tank in the City between 2014 & 2018.
Short Term Remediation Projects
As part of the Chedoke Creek Workplan, offsetting remediation projects have been completed to complement the targeted dredging work. Two initiatives including the installation of floating treatment wetlands and the installation of a small scale aeration system were undertaken to improve water quality conditions in the creek.
- Floating Treatment Wetlands
- Small Scale Aeration
- Targeted Dredging
Long Term Offsetting
In response to the MECP Order, the City of Hamilton is implementing long term solutions to improve the quality of the water. Offsetting projects were identified in the Cootes Paradise Workplan focusing on long term project solutions that improve the quality of water inflow into Chedoke Creek and the receiving bodies of water.
The long term offsetting projects are identified and reviewed through Environmental Assessments, public consultation and policy development. Three Environmental Assessments are currently initiated:
- Lower Chedoke Creek Masterplan
- Sewer Separate – West Tributary
- Watershed Stormwater Mitigation
- Chedoke Creek Environmental Impact Report (pdf)
- Chedoke Creek Background and F.A.Q.s (City of Hamilton)
- Chedoke Creek Targeted Dredging (arcgis.com)
- Chedoke Creek Factsheet (Hamilton Conservation Authority)
- Canadian Water Quality Guidelines for the Protection of Aquatic Life (pdf)
- Financial Assistance Programs (Conservation Halton)
- Let’s Talk Water: Walking Chedoke Creek from Mouth to Spring (BARC)
Support Conservation at RBG
These conservation projects are possible thanks to the generous support of RBG Members and donors. With a donation to Growing up Green, you can ensure an active, vibrant and healthy future for the children of today and tomorrow through our horticultural and conservation projects.