Lower Welland River Characterization Report - Niagara Peninsula ...

Lower Welland River Study Area
Characterization Report
is stressed hydrologically. The Tier Water Budget and Water Quantity Stress Assessment (NPCA
2010d) ties in the Water Availability Study and a Stress Assessment. The report includes a
watershed characterization (climate, topography, geology, physiology, land cover, soils,
streamflow), watershed modelling (model set-up, calibration, verification, sensitivity, results, and
uncertainty), water taking analysis and stress assessment, as well as conclusions and
recommendations. The Stress Assessment was completed for both surface water systems and
groundwater systems; these assessments were conducted separately. A system is considered
moderately or significantly stressed if the demand exceeds a provincial benchmark threshold value
Table 10 (NPCA 2010d).
The Niagara Peninsula Tier 1 Water Budget and Water Quantity Stress Assessment (NPCA
2010d) identified the Lower Welland River study area as having a moderate surface water stress
level based on provincial benchmark threshold values (Table 10). A moderate stress level is
assigned to surface water systems where the maximum monthly water demand consists of 20% to
50% of the surface water supply. The Lower Welland River study area was also identified as
having a low groundwater stress level. A low stress level is assigned to groundwater systems
where the demand for monthly maximum ranges between 0 to 25% or the average annual is
between 0 to 10% of the groundwater supply.
Table 10: Provincial Benchmark Threshold Values
Potential for Surface Water Stress Thresholds
Stress Level Assignment
Maximum Monthly % Water Demand
Significant > 50%
Moderate 20% to 50%
Low < 20%
Potential for Groundwater Stress Thresholds
Stress Level Assignment Average Annual Monthly Maximum
Significant > 25% > 50%
Moderate > 10% > 25%
Low 0 to 10% 0 to 25%
Additional benefits that will result from the completion of the Tier 1 Water Budget include; this
project will satisfy one of the Niagara Water Strategy objectives which is to prepare water budgets
for watersheds within Niagara Region; and the project will aid the NPCA when commenting on
Permit-To-Take-Water (PTTW) applications (Wright 2009).
In Ontario, water takings (both surface and ground) are governed under the Ontario Water
Resources Act (MOE 1990) and the Water Taking and Transfer Regulation. Under the Ontario
Water Resources Act “a person shall not take more than 50,000 litres of water on any day by any
means except in accordance with a permit issued by the Director” (Section 34.3).
Currently in the Lower Welland River and Thompsons Creek subwatershed there are 31 PTTW.
Four of these permits are in the City of Thorold and the remaining 27 are in the City of Niagara
Falls. Eleven of the PTTW are for surface water takings, 6 are for groundwater takings, and the
remaining 14 are for both surface and groundwater. The purposes of these permits are as follows;
fifteen are for commercial uses, 11 industrial, 2 de-watering, 1 for groundwater remediation, 1 for
water supply, and the remaining permit is for agriculture (MOE 2009).
Due to the moderate surface water stress assignments determined by the Water Budget and
Water Quantity Stress Assessment (NPCA 2010d) study and an ongoing fluctuation of water
demand it is recommended that this study be improved further by undergoing development of
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