| Report Documents
|
|
|
| |
| Map Plotfiles
|
-
No files of this type available
|
| |
| Data Files
|
-
No files of this type available
|
| |
| Digital Map Files
|
-
No files of this type available
|
| |
| Image Document
|
-
No files of this type available
|
| |
| Video Files
|
-
No files of this type available
|
| |
|
All Documents
|
|
|
| Contact
|
|
-
If you have any questions on the information presented, or require additional report data or attachments, please contact the Report Contact
|
|
|
A monthly groundwater budget model for the main aquifers underlying the City of Kelowna was developed to support groundwater allocation and licensing under the Water Sustainability Act.
|
Author: Sarah Alloisio & Rod Smith
|
|
|
Date Published: Nov 2016
|
Report ID: 51879
|
Audience: Government and Public
|
This report describes the development of a monthly groundwater budget model for the main aquifers underlying the City of Kelowna. which has experienced significant population growth and expansion in agriculture over the last few decades. Mill Creek, Mission Creek and Bellevue Creek, which run through the Kelowna area, are ecologically important. The BC Ministry of Environment described the Kelowna Aquifers based primarily on existing well records. This study developed a water budget for Aquifers 463, 464 (which includes 465) and 467.
A conceptual hydrogeological model of the Kelowna aquifers was defined based on the review of the relevant studies, maps and available data. Based on the GSC geologic mapping, most if not all of the aquifer units mapped by the ENV potentially comprise a vertical sequence of aquifers. Although each aquifer unit may include aquifer materials at more than one depth interval, all aquifer materials located in vertical sequence was represented in the groundwater budget model as part of the same groundwater budget zone. This discretization is compatible with an adequate representation of surface water - groundwater interaction and acknowledges the probable vertical leakage expected across aquifers, especially over the size of each of the aquifers of interest.
Groundwater flowing in the upland catchments of the local streams discharges primarily into the creek channels, with part of the flow reporting to the Kelowna aquifers. Groundwater recharge to the Kelowna aquifers is mainly provided by water returned from irrigation, urban leakage and septic discharge, followed by streamflow leakage and groundwater inflow from the upland bedrock aquifers. Groundwater discharge mainly occurs to surface (including stream baseflow, wetlands vegetation and losses to drainage works), followed by groundwater withdrawal and with a relatively small discharge to Okanagan Lake. Groundwater discharge to Okanagan lake is believed to be limited based on seepage meter measurements and investigative modelling reported in the literature.The conceptual hydrogeological model was represented in quantitative terms by means of a semi-distributed parameter, spreadsheet-based groundwater budget model. The model was calibrated by identifying a representative climate data and selecting four unregulated catchments with continuous streamflow data sets. Following calibration, a monthly water budget was developed for each of the 42 zones defined in the study area, in different climatic conditions. Average, wet and dry conditions were represented by years selected from the calculated low and high water tables generated by the model using the historic climate data set between 1900 and 2015.
The groundwater budget results are consistent with the general groundwater flow pattern assumed for the Kelowna aquifers, whereby groundwater flows from Aquifer 463 into 467 and 464, where it discharges into Okanagan Lake. Streamflow recharge is prevalent in Aquifer 463, where it represents 33% of the total inflows to this unit. Irrigation loss, urban leakage and septic tank infiltration are a considerable contribution to groundwater recharge in Aquifers 463 and 464, where they represent approximately 32% of the total inflows.
The model was used to compare simulated average streamflows associated with the current water withdrawal conditions and estimated Environmental Flow Needs (EFN). Subsequently, the model was used to estimate effects of future groundwater demand on average streamflow. The report discusses limitations of the modeling approach and sources of uncertainty in model parameters and estimates. The report also provides monitoring recommendations to improve understanding of the groundwater resources and to reduce model uncertainty.
The groundwater budget model presented in this study is not only a helpful water management tool, but also provides valuable information on the surface water - aquifer dynamics in the study area.
|
Report Type
Subject
| |
Watershed Groups - 310 - Okanagan |
| |
Water Information - Groundwater |
| |
|
|
