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Surface Water Quality



Water Chemistry Monitoring

The Rideau Valley Conservation Authority presently monitors water chemistry at 59 stream locations and approximately 45 lake locations throughout the Rideau watershed on a routine basis. The three water chemistry monitoring programs are: Provincial Water Quality Monitoring Network, RVCA Baseline Monitoring Program. Watershed Watch.


Provincial Water Quality Monitoring Network (PWQMN)

Program objective: to provide a consistent baseline dataset that can give a general indication of water quality in the watershed. Click here for the Provincial Water Quality Objectives.

Number of sites:

  • 10 sites throughout the watershed
  • 6 sites are in common with the City of Ottawa monitoring program and 3 with the RVCA baseline program which increases the total dataset for those sites which can allow more detailed assessment.

sampling frequency: 8 times per year about once a month spaced to collect samples from the complete range of flow conditions from April to November

sample variables: 36 nutrients, metals and anions


RVCA Baseline Monitoring Program

Program objectives:
1.) to assess the contribution of tributary streams to loadings in the Rideau River and upper watershed lakes and 2.) to monitor ambient conditions at locations on major tributary streams

number of sites:

  • 52 sites in total
  • objective 1: 17 at or near the mouth of tributaries, objective 2: 9 sites on Kemptville Creek, 15 sites on the Tay River, 1 on Fish Creek — increase of 10 from 2002 to 2003 — 3 RVCA baseline sites are in common with the PWQMN, as mentioned above, and 2 are also sampled under the City of Ottawa program

sample frequency: once in May, September and October, twice per month June, July and August.

sample variables: 31 bacteria, nutrients, metals, dissolved solids and anion variables — increased from 4 bacteria, nutrients and suspended solids previously


Watershed Watch

Program objectives: to intensively sample the 45 major lakes in the watershed on a regular cycle to help identify trends in water qulaity. To view general information on the program, newsletters and state of the lake reports, click here.

number of sites:

  • 91 in 2003 (varies each year depending on lakes); 1 site at lake deep point (surface and bottom samples, dissolve oxygen/temperature profiles), average 8 inshore sample sites near possible pollution source points/areas

lakes sampled through 2003: Farren, O’Brien, Davern, Little Silver/Rainbow, Crosby, Little Crosby, Pike (2001); Otty, Long (Tay Valley Township), Westport Sand, Eagle, Black, Burridge, (2002); Christie, Otter, Bobs (Buck Bay, West Basin, Green Bay/Narrows, East Basin), Crow (2003). Click here to access the 2001 State of the Lake Reports.

sample frequency: once in May, September, October; twice per month June, July, August

sample variables: total phosphorous (TP), total Kjeldahl nitrogen (TKN), dissolved organic carbon at deep points; TP,TKN, Eschericia Coliform (E.Coli.) at inshore sites (sampled at half metre depth in approximately one metre of water)


Understanding Water Chemistry— Sampling methods:
Provincial Water Quality Monitoring Network (PWQMN)
RVCA Baseline
Watershed Watch

Provincial Water Quality Monitoring Network (PWQMN):

  • a “grab” sample at approximately 30 centimetres depth taken standing in the water where possible, from the bank using an extension pole or from a bridge using a sampling cylinder on a rope
  • lab analysis at the Ministry of Environment lab in Etobicoke
  • field measurements of pH, dissolved oxygen, conductivity and temperature

RVCA Baseline:

Watershed Watch

  • Go to the Watershed Watch web page
  • grab samples taken at a half metre depth in about one metre of water near the lake shore; composite sample at the deep point of the lake in the “euphotic” zone (surface zone of light penetration); alpha bottle sample one metre above the lake bottom at the deep point
  • lab analysis at City of Ottawa lab at the Robert O. Pickard Environmental Centre
  • field measurements of pH, conductivity, deep point surface and bottom water temperature; dissolved oxygen/temperature profiles at deep point



The Provincial Water Quality Monitoring Network (PWQMN) data is presented in scatter charts relative, in most cases, to the PWQO or guideline. It is obvious in all cases how the variable is performing. As well, there is a finger chart for each variable that shows the comparison from site to site. The fingers show the maximum and minimum concentration and the box shows the spread of the data between the 25th and 75th percentile. In other words, 50% of the data falls within the box. The shorter the fingers, the smaller the box, the lower on the scale the data falls and if the same pattern occurs for all variables, the better the water chemistry quality at the site is.

At this time, the RVCA baseline data is presented in its entirety. When a site is selected on the WIS map, the dataset for that site will be opened. The variable list was expanded in 2003 so there is only one year of data for many variables which is not sufficient for any statistical analysis. The data can be compared to the PWQO or guideline where available which will give some indication of what has happened in each area over the summer. Where the chemistry monitoring site is also a benthic macroinvertebrate monitoring site, the biological data will give an indication of the longer term situation.

The published reports for the Watershed Watch 2001 program are available online. The 2002 and 2003 reports are expected by April 2004. Until then, the dataset is available as for the RVCA baseline program.