Subwatershed Reports

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1. Catchment Facts

LandCoverIrish-Creek-001-001

General Geography

  • The Rideau River flows through the heart of the Middle Rideau and is a focal point for residents and visitors to the area. It extends from the outlet of Lower Rideau Lake at Poonamalie (where there is one dam and one lock) to Burritts Rapids (where there is also a dam and lock), at which point it enters the Lower Rideau on its way to Rideau Falls. The Rideau River is also an integral part of the Rideau Canal National Historic Site of Canada and is a significant tourist attraction which draws boaters, cottagers, and campers to the area
  • Smiths Falls, Merrickville and Burritts Rapids are the main settlements in the Middle Rideau subwatershed. The Irish Creek catchment is predominantly rural in character with agriculture being the main land use. Settlement areas include Jasper, Toledo, Newbliss, Frankville, Bellamys Mill and Lehighs Corners
  • Parks Canada staff manage water levels for recreational purposes along the Rideau Canal/Waterway that flows by the catchment, ensuring 1.5 metres of draft during the navigation season. In this managed system, water levels on the Rideau Canal are manipulated by operation of numerous dams. In the Middle Rideau subwatershed, Parks Canada staff operate 9 dam and lock complexes with 13 locks for a fall of 36.2 metres over 35.6 kilometres. Water levels are maintained as close as possible to set objectives through the May to October navigation season. The levels are lowered through the rest of October and into November and held at the winter levels until the spring freshet in late March or early April naturally increases inflows to the system. To reduce the impact of the higher flows in the spring, the amount of snow water equivalent, forecast rain, ice cover, flows and levels are assessed and the dams in the Middle Rideau reach are operated accordingly to quickly pass as much water as possible. In late April and early May, the dams are gradually closed and water levels are brought up to be ready, once again, for the navigation season

Physical Geography

  • All of Irish Creek Catchment and the rest of the Middle Rideau Subwatershed primarily resides within the Smith Falls Limestone Plain, which in this area, happens to consist of older Paleozoic quartz sandstone and dolostone of the March Formation. The bedrock across the catchment is mainly overlain by a thin veneer of glacial sediment, referred to as ‘drift’ that is generally less than a metre in thickness; although the south western area is overlain by glacial till and Irish Creek’s corridor is underlain by clay and organic deposits
  • Seventy-seven percent of the catchment lies within the Township of Elizabethtown-Kitley, 14 percent within the Township of Rideau Lakes and nine percent within the Village of Merrickville-Wolford
  • Irish Creek catchment drainage area is 161 square kilometres and occupies about 19 percent of the Middle Rideau subwatershed and four percent of the Rideau Valley watershed
  • Parks Canada staff manage water levels for recreational purposes along the Rideau Canal/Waterway that flows by the catchment, ensuring 1.5 metres of draft during the navigation season. In this managed system, water levels on the Rideau Canal are manipulated by operation of numerous dams. In the Middle Rideau subwatershed, Parks Canada staff operate 9 dam and lock complexes with 13 locks for a fall of 36.2 metres over 35.6 kilometres. Water levels are maintained as close as possible to set objectives through the May to October navigation season. The levels are lowered through the rest of October and into November and held at the winter levels until the spring freshet in late March or early April naturally increases inflows to the system. To reduce the impact of the higher flows in the spring, the amount of snow water equivalent, forecast rain, ice cover, flows and levels are assessed and the dams in the Middle Rideau reach are operated accordingly to quickly pass as much water as possible. In late April and early May, the dams are gradually closed and water levels are brought up to be ready, once again, for the navigation season

Vulnerable Areas

  • The Assessment Report developed under the Ontario Clean Water Act identifies the upper bedrock aquifer underlying all of the catchment area as a Highly Vulnerable Aquifer, although, where sediments are thicker in a local area, the vulnerability would be less

Development

  • Land uses in the catchment are Rural and Agriculture with Natural Heritage-Provincially Significant Wetland

Conditions at a Glance

Water Quality

  • Surface chemistry water quality rating in Irish Creek is “Good” (2009 to 2014) and has improved from a “Fair” rating in the 2003-2008 reporting period. While elevated total Kjeldahl nitrogen is a feature of Irish Creek, nutrients and E. coli counts have decreased between the two monitoring periods
  • Instream biological water quality conditions at the Irish Creek sample location range from “Very Poor” to “Poor” from 2003 to 2014 (using a grading scheme developed by Ontario Conservation Authorities in Ontario for benthic invertebrates) with an overall rating of “Poor” from 2003 to 2014 as the samples are dominated by species that are tolerant of high organic pollution levels

Instream and Riparian

  • Overall instream and riparian condition for the Irish creek catchment as assessed by the stream characterization and headwater drainage feature assessment programs show that Irish Creek and its tributaries are in generally good condition. The majority of the system has a healthy riparian corridor with minimal erosion levels along the system. Instream diversity of aquatic habitat is somewhat variable with low levels of riffle habitat and high levels of riverine wetland habitat along the system. Several opportunities were identified on headwater tributaries of Irish Creek to enhance riparian habitat conditions along with one invasive species removal close to the Rideau River. Several beaver dams and one perched culvert were identified as potential migratory obstructions for fish passage
  • The Irish Creek catchment has 22 species of recreational and bait fish that is classified as having a warm/cool water thermal guild that supports the Irish Creek/Rideau River fishery
  • In the Irish Creek catchment, the riparian buffer (30 m. wide strip along the shoreline of all lakes and streams) is comprised of wetland (53 percent), crop and pastureland (25 percent), woodland (18 percent), roads (two percent) and settlement areas (two percent)

Land Cover

  • Dominant land cover is crop and pastureland (39 percent) and woodland (35 percent) followed by wetland (20 percent), settlement areas (four percent) and roads (two percent). From 2008 to 2014, there was an overall change of 195 hectares (from one land cover class to another), most of which is associated with crop and pastureland emerging as young woodland along with some smaller areas of woodland conversion to crop and pastureland
  • Woodland cover in the catchment has decreased by 80 hectares between 2008 and 2014 and interior forest habitat has increased by 42 hectares
  • Wetland cover has decreased by two percent (363 ha) from pre-settlement times to the present and now occupies 20 percent of the catchment area

Other

  • There are approximately 720 to 760 in-use water wells with provincial records in this catchment. While most water wells are used for domestic water supply, in this catchment, several are also used for commercial, agricultural, municipal and public water supplies or cooling
  • An Environmental Compliance Approval has been issued in this catchment for municipal sewage works and several Permits to Take Water have been issued for wetland conservation
  • There are three bedrock aggregate licenses located in this catchment
  • Groundwater information from a discontinued historic Provincial Groundwater Monitoring Network well is available from the MOECC

Catchment Care

  • Thirty-nine stewardship projects have been completed with assistance from the RVCA’s Rural Clean Water, Tree Planting and Shoreline Naturalization Programs (see Section 5 of this report for details)
  • Irish Creek surface water quality has been monitored by the RVCA through its Baseline Monitoring Program since 2003. The surface water quality at site IRI-02 is monitored once a month from April to November
  • RVCA has been collecting benthic invertebrates in Irish Creek at the Kinch Street site since 2003
  • RVCA conducted a fish survey along Irish Creek in 2014
  • RVCA completed a beaver dam survey on Irish Creek between Jasper and Toledo. Thirteen beaver dams were identified/mapped in 2012 and 9 beaver dams were identified/mapped in 2014
  • RVCA completed a the stream characterization survey on Hutton Creek in 2014, working upstream to the headwaters from the mouth of the creek where it empties into the Rideau River taking measurements and recording observations on instream habitat, bank stability, other attributes and preparing a temperature profile
  • RVCA completed 34 headwater drainage feature assessments at road crossings in the Irish Creek catchment in 2014. This protocol measures zero and first order headwater drainage features and is a rapid assessment method characterizing the amount of water, sediment transport, and storage capacity within headwater drainage features
  • A watershed model developed by the RVCA in 2009 was used to study the hydrologic function of wetlands in the Rideau Valley Watershed, including those found in the Irish Creek catchment
  • The Townships of Elizabethtown-Kitley and Rideau Lakes and the Village of Merrickville-Wolford have land use planning policies and zoning provisions - on water setbacks, frontage and naturalized shorelines and wetland protection - and in some instances use site plan control to implement these policies and provisions. Together with RVCA, these municipalities work with landowners on a case by case basis to enable new development while ensuring the scale is suitable on the lot, impacts on neighbours are minimized and development maximizes the watercourse setback
  • Development in and adjacent to the Provincially Significant Wetlands in the catchment (Bellamys Lake, Irish Lake and Creek, Marshalls Creek, Newbliss Swamp, Otter Lake-Hutton Creek Complex) are subject to Ontario Regulation 174-06 (entitled “Development, Interference with Wetlands and Alterations to Shorelines and Watercourses”) that protects the hydrologic function of the wetland and also protects landowners and their property from natural hazards (flooding, fluctuating water table, unstable soils) associated with them