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Monitoring Surface Water Quality

The Thames River is sampled on a regular monitoring program at 10 locations.  The parameters analyzed include biochemical oxygen demand (BOD), pH, temperature, dissolved oxygen, total phosphorous, ammonia, bacteriological quality, suspended solids, chlorides, nitrates, nitrites, and conductivity.  Heavy metals are sampled at Clarke/Highbury, Whites, Byron and Komoka bridges.  Monitoring is also conducted on a number of creeks in the City of London on a monthly basis.

Water quality in the Thames River has improved significantly since river monitoring was initiated in 1963.  The dissolved oxygen levels have increased.  Wastewater treatment has improved from 90% efficiency in the 1960s to the present where 98% of the BOD is removed.  Typical wastewater treatment plants have an efficiency of 85 to 95% for BOD.  The City of London Wastewater treatment plants remove 95% of suspended solids and 90% of total phosphorous.


Water Quality Monitoring Data up to 2019

  • There is a lot of data, but is it good or bad?  The Ministry of the Environment has produced surface water quality objectives.  Look for Table 2 and compare the data to the objectives to determine if it is good or bad. Check the bookmarks in the pdfs to find annual data, daily data, annual graphs and daily data graphs.
  • The Springbank data below has a comparison of annual averages with Wharncliffe, Springbank and Byron to see differences as the water moves through the City on the main branch of the Thames River.
  • The Richmond data below has a comparison of annual averages with Highbury on the north branch of the Thames River.
  • The York data below has a comparison of annual averages with Whites on the south branch to see differences as the water moves through this part of the city.
  • The Dundas data below has a comparison of annual averages for the Fork of the Thames (North and south branch join) with data from York and Wharncliffe.
  • Dingman Creek has five monitoring stations and the annual averages can be found on Old Victoria data below.

Thames River Main Branch


  • Wharncliffe   42.980802, -81.262528
  • Springbank    42.962344, -81.298768
  • Byron                42.963030, -81.331907
  • Komoka           42.934779, -81.421519
  • Giles                  42.871736, -81.388650


Thames River North Branch



Thames River South Branch


  • Whites        42.968617, -81.150141
  • Adelaide     42.975301, -81.225807
  • York              42.977321, -81.255891




  • Stoney             43.022304, -81.252017
  • Medway           43.014700, -81.276676
  • Pottersburg   42.975198, -81.176022
  • Coves               42.975963, -81.275416


Dingman Creek

  • Old Victoria                                               42.921653, -81.134443

(has annual trend comparison for all Dingman Creek Sites)

  • Highbury (South of 401)                        42.915524, -81.192958
  • Wellington Rd.                                            42.912837, -81.214955
  • Dingman Drive (at White Oaks Rd.)  42.910994, -81.245580
  • Lambeth                                                         42.914150, -81.313617

Dissolved Oxygen 24 Hour Monitoring Data

Water Quality Sampling Locations


Monitoring Locations