By Ella Swan and Megan Peloso
Metro Vancouver officials announced last week that lawn watering will be restricted to one day a week, in the wake of the driest spell since 2003. A little farther southwest, California is facing one of the worst droughts on record, with speculation that it could be a “mega-drought” persisting upwards of 20 years. And it’s not only surface water that is at stake; there are serious concerns that groundwater aquifers are being overdrawn. Normally, California draws 40% of their total water from aquifers, however this year it has increased to 60%. Once an aquifer is depleted it takes a very long time to recharge. An absence of groundwater also leads to greater susceptibility of salt-water intrusion, a phenomenon where ocean water seeps in and turns underground fresh water briny and brackish.
There are four main types of drought: meteorological, agricultural, hydrological and socio-economic. Meteorological and hydrological droughts pertain to precipitation and surface, and subsurface stored water, respectively. Agricultural drought is closely linked, but refers to soil and subsoil moisture content with regard to plant growth. Socio-economic drought occurs when supply is unable to meet demand due to meteorological, hydrological and agricultural deficiencies.
Paleoclimatic techniques such as tree-ring assessments allow scientists to estimate when droughts have taken place over the course of thousands of years in the Americas. Data shows that over the past 400 years, multi-year droughts have occurred in the Great Plains (eg. Dustbowl of the 1930s) as often as twice per century. Like rivers gradually changing course or forest fires renovating landscapes, droughts are a natural phenomenon that modern society has little choice but to adapt to.
We can look to the natural world for clues on how to manage water to promote resilience against stresses. Whereas roads and other impervious surfaces shed water quickly into basins, wetlands capture and retain water. When we build over wetlands, we are reducing the ability of aquifers to recharge. Grasslands are able to go dormant for long periods of time, and use little water. Floodplains are some of the world’s most diverse and productive landscapes, and act as a catchment for groundwater in the event of a flood. Unfortunately floodplains are also located on shorelines popular for development and this eventually causes problems for people living in the area and reduces the effectiveness of the natural flood management system.
The District of Invermere’s Drought Management Plan reviews water supply and requirements, acknowledging growing stresses on water resources in our area from population growth and climate change. However a Management Plan is just the first step, and public awareness is needed to make an impact on drought preparedness.
Are you aware that British Columbians are the nation’s highest users of water at 490L per person per day? Irrigation accounts for 75% of domestic water use, so consider letting your lawn “sleep” during summer, or water minimally. Currently, Invermere is under a Stage 1 Water Restriction, which means all houses are expected to alternate watering days based on house number, and to do so in the early morning or the evening to reduce evaporation loss.
The Regional District of East Kootenay asks that residents in Windermere, Timber Ridge, Holland Creek and Edgewater refrain from watering on Fridays to allow reservoirs to replenish.
Consider other ways you can save water, and remember that by doing so you are helping to sustain the Columbia River and its watershed. Although it is a bit of a dry subject, talking with your neighbours and informing the people around you will help to make a big difference when it comes to mitigating drought.