Water supply is a legitimate concern in the Milk River watershed during dry summer months. A 2008 engineering report identified a number of possible supplementary water supply routes from the northerly Ridge Reservoir to the Milk River. The three preferred technical routes were:
- Route 2C—an open gravity canal from Ridge Reservoir to Middle Coulee past Warner to the Milk River, discharging 16.1 km (10 miles) east of Milk River town.
- Route 4C—a pump and short pipeline and then an open canal from the Ridge Reservoir following north of the Milk River Ridge and discharging into the river 3.2 km (2 miles) west of Milk River town.
- Route 4P—a pump and pressure pipeline from the Ridge Reservoir following north of Milk River Ridge and also discharging into the river 3.2 km (2 miles) west of the Milk River town.
Socio-economic assessments of the three alternative Ridge Reservoir supply routes were conducted by employing a conventional benefit-cost method and a regional impact assessment.
Incremental direct costs are:
- Diversion construction & operating costs
- On-farm irrigation expansion costs
- Annual incremental on-farm production costs
- Additional recreational development costs
- Environmental studies & related mitigation costs
Corresponding incremental direct benefits are:
- Enhanced existing irrigation crop-livestock development (8,200 acres)
- New irrigation crop-livestock development (10,000 acres)
- Enhanced recreational/tourist opportunities (park activities, river rafting, related)
- Improved municipal water supplies
- Improved livestock water supplies
- Option values, preservation values and existence values
Other regional benefits of a more abundant and reliable water supply include:
- Improved income stability in the watershed,
- Improved income levels in the watershed, and
- Establishing the potential for new economic activities in the watershed.