Agriculture and Irrigation - Request for Proposal - Carseland-Bow River Headworks Capacity Assessment 2024

This project has been initiated to assess the capacity of the Carseland-Bow River Headworks (CBRH) system and study the feasibility of increasing its capacity. The project is motivated by the efforts of the Province of Alberta to enhance operational flexibility and increase water security during times of low flows in the Bow River Basin while keeping the mandate to satisfy the water licenses downstream of the headworks. PROJECT DESCRIPTION Background The Carseland-Bow River Headworks (CBRH) system is located approximately 60 km southeast of Calgary. The purpose of the system is to divert, impound and release water for water management, water supply (including irrigation), flow regulation, conservation, and recreation. It diverts water from the Bow River at the Carseland weir to the Bow River Irrigation District (BRID) and Siksika Nation. The system provides irrigation water to about 119,000 hectares in the Bow River Irrigation District (BRID) and Siksika Nation through its main canal. It also provides water to several municipalities, domestic users, livestock operations, and sports/commercial fisheries, and recreational activities. Alberta Agriculture and Irrigation (AGI) owns the CRBH system and contracts the BRID for operations and maintenance support. Key operational and maintenance decisions are authorized by AGI. This water supply system is valued at approximately $1 billion and is a critical infrastructure for southern Alberta. The CBRH system consists of the diversion headworks, main canal, several water conveyance structures (e.g., syphons, drain inlets, turnouts, etc.), three main reservoirs (McGregor, Travers, and Little Bow reservoirs) and about 4.6 km of connecting canals between the reservoirs. The system is then followed by the BRID canal systems, the Vauxhall main canal, and the Lomond lateral starting downstream of the Little Bow Reservoir. The headworks diversion structure diverts up to 51 m3/s of water from the Bow River into the main canal during the irrigation season. This diversion is controlled by three radial gates. The total length of the CBRH main canal traveling east from the headworks then south toward McGregor reservoir is approximately 65 km. The left bank of the canal is mainly constructed embankment and the right bank is higher ground with a natural slope toward the canal. The total drop in the canal bed elevation from the diversion headgate structure to McGregor Reservoir is 34 m. In addition, there are two syphons and seven check/drop structures that control the grade of the canal. The last drop in the system serves as the inlet to McGregor Reservoir. The extent of this project is from the headgates to the inlet of McGregor reservoir and the structures in between.