The amount of water allocated in a basin is important to know; however, it needs to be put into perspective. You need to consider not only the total amount of water allocated, but also how the allocations compare to the potential available supply. The following graph shows the absolute amount of water that is allocated as compared to the average natural flow.

The Peace and the Athabasca Rivers, which extend beyond the edge of the chart, are so large that the scale had to be adjusted so details for the other basins would still be visible. The same information is shown below but with the allocated volumes shown as a percent of the available average natural supply (=100%). This measures all rivers to the same relative standard.

By this measure, the South Saskatchewan has been allocated to almost 70% of the average natural flow, while the North Saskatchewan is over 27% of natural.

The Battle River, apparently allocated to 278% of natural, is misleading because of a single license that continuously diverts and recirculates water before returning it to the river. When actual consumption in the basin is estimated, the more likely range of the allocation drops to under 30% of natural flow. This is a great example of how allocations only represent the maximum amount that can be taken, and do not consider any return flows that put water back that other licenses can use again downstream.

In general we often do not know how much is actually consumed - only that each license provides an estimate of what we expect the upper limit of what the losses and consumption might be. This is based on the type of activity or usage and process requirements.

Therefore, it is important to consider not only the gross allocation amount, but also what the use of water will be and how much may be actually consumed or eventually returned to the water body. Depending on how the water is needed, the actual amounts that are consumed or not returned can be much less than the overall total allocation.

Alberta Environment has an Indicator that shows the level of water allocation in Alberta's major basins. You can see the map on the State of the Environment web site.

Groundwater
On the whole, Alberta does not rely very heavily on groundwater resources - only 3% of all water allocated comes from groundwater. However, groundwater is a water source that is easily impacted by neighbouring activities and wells, especially in areas where there is intensive development of groundwater. It is also an important water source for many rural communities and farms. Note that individual domestic (household) is a fairly large use of groundwater overall but it does not require a license and therefore is not accounted for in licensing totals. Therefore, actual groundwater use is probably somewhat higher than what is indicated here. In the previous section, total groundwater allocations were considered by combining them with surface allocations. This was to compare total allocations, from all sources, to the volume of water available in the major rivers. Another way to look at the potential amount of groundwater available for use is to estimate the annual natural recharge that might be expected as a result of precipitation infiltrating into the ground to replenish aquifers. Such an estimate is shown in the chart below.

This type of assessment shows that the amounts of allocated groundwater are for the most part a very small fraction of what might potentially be available for use. This doesn't mean there aren't times at a local or regional scale where groundwater is scarce or not easy to pump. This is especially possible in areas where many wells are sourcing a single aquifer, or where local geology makes groundwater extraction more complex. What it does suggest is at a provincial scale, groundwater allocations are small when measured against potential supply.