Progress Towards Water Quality Goals in the Upper Thames River Watershed
In 2016, the Upper Thames River Conservation Authority (UTRCA) implemented a Strategic Plan to help support environmental sustainability within the watershed, with one of the key areas focusing on improving water quality. The goal for water quality throughout the UTRCA jurisdiction is to improve each subwatershed’s report card score by one letter grade by the year 2037. Conservation Authorities release watershed report cards every five years that are scored on a letter grade system. One strategy that that may help meet our goal is to encourage landowners and farmers to participate in our Phosphorus Reduction Program. An example of this would be to incorporate the 4R concept into their agricultural practices. This is a Best Management Practice (BMP) that helps keep nutrients, particularly phosphorus, in the farm field rather than running off into the watercourses. The 4Rs stand for Right source, Right rate, Right time, and Right place, referring to the responsible application of fertilizers to crops. Another way to aid in this endeavour is to expand our water quality monitoring efforts, allowing us to fill in knowledge gaps and implement science-based decision-making.
Water quality is assessed using three indicators: total phosphorus, bacteria, and benthic macroinvertebrates. Phosphorus comes from many sources including fertilizers, detergents, and waste. Excessive phosphorus in a water system contributes to algae blooms and low oxygen levels, negatively impacting aquatic ecosystems. E. coli is a form of coliform bacteria present in human and animal waste. High concentrations of E. coli indicate the potential for other harmful pathogens, posing a health risk. Benthic macroinvertebrates are aquatic insects/small organisms that live at the bottom of a stream within the sediments and serve as a bioindicator of water quality and stream health. Diverse and healthy benthics populations are associated with better water quality. Each indicator is impacted by the land use activities in the area, including, but not limited to, agriculture, road salt application, and urban development. Much of the area within the Upper Thames River watershed is heavily influenced by either urbanization or agriculture practices, contributing to an average watershed grade of D.
Despite the current letter grade, UTRCA watersheds are seeing an improvement in water quality. Pottersburg Creek in the City of London has seen steady total phosphorus levels since 2017, and levels are just slightly above the UTRCA goal of C. Compared to some of the phosphorus numbers in other areas of the watershed, this is relatively low. The Avon River has shown improvement in the concentrations of E. coli since 2015 and is also approaching our goal of letter grade C. Plover Mills Corridor is the furthest from its benthics goal, however its current letter grade is currently B, the best in the Upper Thames watershed.
In addition to the improvements above, some subwatersheds have already met their goal regarding the above indicators. Wye Creek has surpassed its total phosphorus goal and is currently sitting at a grade D, while Ingersoll Corridor’s bacteria grade has improved from a D to a C since 2017. Dorchester Corridor is currently the only subwatershed to have met its goal regarding benthics, and has moved from a D in 2017 to a C in 2022. To date, 8 subwatersheds out of a total of 28 have already met or surpassed at least one of their 2037 water quality goals. Many of the other subwatersheds are showing improvement and are on track to meet their targets in the future.
Overall, our total phosphorus goal has been met in five subwatersheds, E. coli bacteria goal has been met in three, and benthics have been met in one. Given the external pressures on our environment, it is remarkable that the grades have improved or remained stable. Water quality monitoring, and implementation of stewardship practices such as our Phosphorus Reduction Program, have and will continue to help improve water quality conditions in the coming years.
For more information visit the Upper Thames River Phosphorus Reduction Program website.