The City of Dawson Creek has an excellent water storage and treatment system which is a source of justifiable pride. The system has recently had a 5.2 million dollar upgrade which has increased the storage, treatment and pumping capacity. From the Kiskatinaw River, raw water is pumped to the Harald Hansen Reservoir, which holds approximately 100 million US gallons. From the Hansen Reservoir the water is pumped to the Hart Reservoir, which holds approximately 8 million US gallons. After leaving the Hart Reservoir the water is gravity fed into the Trail Reservoir, which has a capacity of 85 million US gallons. Water from the Trail Reservoir is gravity fed to the Water Treatment Plant.
The Water Treatment Plant can now produce approximately 3.5 million US gallons per day. A high usage summer day ranges from 2.5 to 3.0 million US gallons per day. The Parkhill Reservoir can hold approximately 2.0 million US gallons of treated water, and acts as a buffer for high demand times. The pinch point of the system is at the Kiskatinaw River where the operating permit allows the City to pump a maximum of 2.4 million gallons ( U.S. ) per day but, with the installation of high volume pumps at the river, the system will be able to supply raw water 365 days a year.
Daily water use within the City can double at times during the summer months. This is almost entirely due to outdoor watering. Studies show that 40% of water produced by a municipality in a given year is consumed domestically and 70% of that water is used for lawn watering and toilets. Demand studies done in Winnipeg showed that residential use of water rose 2% annually compared with commercial increases of 0.5% and a decrease of 0.3% in the industrial sector. These findings suggest that the residential sector should be the primary target for demand management.
Demand Management Strategies
There are a number of commonly used strategies for managing the demand for treated water. These have been studied in various jurisdictions and the impact on demand calculated. The results are as follows:
| Strategy |
Water saved
|
| Water scheduling |
10%
|
| Irrigation |
10%
|
| Metering |
30%
|
| Public education |
10%
|
| Leak detection |
10% – 15%
|
| Increasing block pricing |
25% – 30%
|
Metering, the most effective demand management tool, is already in place in Dawson Creek and has long been accepted by the residents. The City has recently started a program of introducing irrigation in City parks in order to reduce watering needs. The next most effective means of managing demand is increasing block pricing.
Pricing as a Conservation Strategy
The price system is the principal mechanism for resource allocation in western societies. When accurate signals about the true costs of resource use are not received, the public inevitably fails to employ available resources in an optimal manner. Increasing block pricing reduces water use by increasing per-unit charges for water as the amount used increases. For example, the first volume of water (block) is charged a base rate, the second block is charged the base rate plus a surcharge, and the third block is charged the base rate plus a higher surcharge. It is necessary to increase real prices significantly to offset the effects of conservation.
As an example, when the cost of water increased in Tucson, Arizona, residents used 33% less water between 1974 and 1980. A 10% increase in water rates provided about 3% more revenue while triggering a 7% reduction in use. Using seasonal increasing block rate pricing during winter and summer months to encourage year-round conservation resulted in estimated water savings for the residential class in Tucson of an average 2.23 million gallons per day.
Water demand becomes more elastic as it moves from the interior of the house to the exterior. That is to say, demand for water for lawn maintenance falls as the price of water increases while demand for drinking, bathing and cooking remains the same. Any attempt to implement increasing block pricing should ensure that the inelastic aspect of water use is not affected.
In order to be effective and accepted water demand management must be part of an overall strategy. Public education and civic leadership are important in order to deliver the benefits desired by consumers: potable water, sanitation, attractive yards etc. The City must also be seen to be a part of the conservation effort through more efficient watering, installation of low flow fixtures and more use of xeriscape (landscaping for low water use) principles.
