The polygons in this dataset are from Alberta Environment and Parks and are the Hydrologic Unit Code Watersheds of Alberta level 8 watersheds (HUC8).

Recharge:

Recharge Modelling:

Recharge was estimated throughout the white area in the upper Peace region through recharge modelling which incorporates three steps:

1. Terrain analysis in ArcGIS of individual depressions and their catchments in order to derive upland-depression characters within the study area for four types of surficial deposits.

2. Modelling of recharge using a suite of simulations with varying catchment and depression areas, crop types, and meteorological data from different stations.

3. Spatially distributing the modelled recharge results based on surficial deposit types.

Baseflow:

Baseflow at each hydrometric gauging station was determined using recorded streamflow rates from the HYDAT database. Daily data from the HYDAT database was aggregated into weekly and monthly data to supplement record gaps. Percentiles were calculated from average monthly flows and expressed as a percent exceedance. The lowest monthly Q95 streamflow value, which is equivalent to the 5th percentile, was chosen to be the representative of baseflow for each hydrometric gauging station within the study area.

The Q95 determined for each hydrometric gauging station is not representative of baseflow generated solely within that zone; rather, it is an accumulation of baseflow up until that point and may include many zones depending on how many tributary zones are located upstream. Therefore the Q95 value(s) from hydrometric gauging station(s) immediately upstream of each zone were subtracted from the Q95 of that zone.

Discharge:

Under the assumption that in a steady-state, closed basin, inputs are equal to outputs; the rate of natural discharge within each HUC8 watershed would be equivalent to recharge. Two permissive sustained yield (PSY) values were calculated to illustrate how PSY will fall on the continuum. In the first scenario, 90% of natural discharge was desired to stay in the groundwater system; this is described by Gleeson and Richter (2018) to be a presumptive standard for ecological protection in the absence of more detailed assessments. The second scenario falls in the middle of PSY range, where 50% of natural discharge was desired to stay in the groundwater system. These scenarios are equivalent to assuming pumping represents 10% and 50% of the simulated recharge for the PSY class.

Volume:

Aquifer volumes to a depth of 150 m below ground surface were estimated from the AGS' 3D Provincial Geological Framework Model of Alberta, Version 2.