The City's automated, centrally-controlled water management system uses weather data to decide how much water needs to be applied during our watering season (May 1 to September 30).
How The City uses weather data for irrigation purposes
The City has two weather stations, one located at 90th Avenue Depot (3520 90 Ave. S.W.), and the other is located at the North West Recreation Centre (9801 Nose Hill Dr. N.W.). Additional weather stations will be added to the system over the next few years.
The City uses weather stations by Campbell Scientific Corp. and Evapotraspiration Software (Weather 2000) by Aqua Engineering. Each evening, the Weather 2000 software calls the weather stations to gather the information for the day, and then uses the data to decide how much water needs to be applied to our parks during the early morning watering cycle. This information is then automatically handed off to the ICC software and dispatched to field controllers in the parks.
Our weather data software measures several different things, including minimum temperature, maximum temperature (both in Fahrenheit), relative humidity (%), solar radiation (in Langleys) and wind run (miles/hour), rainfall (inches) and calculates ETo (inches/day). The system can also do these measurements in Metric, but currently the irrigation industry uses ETo in U.S. measurements so our system is set up to follow that standard. Using these measurements we are able to understand how much moisture has been depleted from the soil and how much we need to replenish. Early in the spring, we fill a six-inch profile of soil with water for the plants and as evapotranspiration occurs we are replacing this moisture depth. For example, should our calculations from the weather data show that we have depleted this depth by one-half inch we will water to replace that amount.
Further calculations are done with the data, including the sprinkler type and the area to be covered, as well as water pressure, so that we may calculate an efficient method of applying the required amount of water.
Want to know more? Environment Canada provides a short interactive tutorial of how a weather station works.
About the City's irrigation process
Normally, The City waters parks 4 days per week, with three cycles during a watering day. This enables the water some time to soak into the ground before we apply water again. Some parks use non-potable water for irrigation.
Our watering system normally runs between midnight and 7 a.m. in order to allow the public the best use of the park area and to provide water at the optimum time of the day for the plants.
Most of our IRRInets have been equipped with rain and freeze switches, so we are also able to prevent watering when community weather events make it unnecessary or when it may harm the plants.
While The City uses a combination of weather data and other information to assess the required water, there are several types of software that are available online for home use. One such software is WISE Software, by Washington State University, and another is available from Irrisoft.
For definition of special terms please refer to the Glossary.