Water Allocations, Water Consumption and Use, Return Flows
Water allocations are based on the expected maximum amount that an applicant may require annually. In the past, these allocations were typically granted under the presumption of total consumption; mandated return flow was often not a condition of a water license in the past but this is changing with new licenses. Also, the cost of the license, and therefore the water to the end user, as a rule has been based on the cost to collect, clean, store and/or distribute the water. The water itself has been essentially free. Until recently there have been few economic or other incentives to conserve water.
In general, three water use factors are considered in issuing licenses for water allocations. Allocations reflect the amount of water that the licensee is expected to consume, plus losses due to seepage or evaporation, and in some cases an allowance for returning water back to rivers and lakes after use. The term “licensed water use” reflects those components of the allocation that are expected to be consumed or lost.
- Allocation = Water Use + Return Flow
- Water Use = Consumption + Losses (Evaporation and/or Seepage)
- Return Flow = Diversion – Water Use
The return flow allowance is important because return flows represent water that can be available for use by other licensees. In the past, these return flows were taken into consideration by AENV when they assessed how much water was available for additional licensing specifically in the South Saskatchewan basin. However, the return flow allowances are often not enforceable. This represents a significant policy challenge: balancing the desire for increased conservation and reuse with the need to maintain flow levels in the river for downstream users and a healthy aquatic ecosystem.
The water use information associated with each licence was also organized into several categories:
- Licensed Allocation: The maximum amount of water that a licensee is permitted to divert from a water body. Water allocations from Alberta Environment outline the volume, rate, timing, and any restrictions for the diversion of water. It is the sum of the licensed consumption and licensed return flows.
- Licensed Consumption: The amount of water the licence holder is permitted to divert that is not entirely or directly returned to a water body. It includes seepage and other losses within the system.
- Estimated Consumption: The approximate amount of water actually diverted by each licensee that is not entirely or directly returned to the water body.
- Licensed Return Flow: The amount of water licensed for return to a water body after withdrawal.Water can be withdrawn from one water body and returned to another, sometimes to one in a different sub-basin. Return flows may also include drainage water from surface runoff or shallow groundwater discharge.
- Estimated Return Flow: The approximate amount of water actually returned to a water body after withdrawal by each licensee.