A drop in regional water use following the imposition of a complete lawn sprinkling ban has Metro Vancouver cautiously optimistic that even tougher water restrictions can be avoided.
The regional district declared stage 3 water restrictions July 20, outlawing any home sprinkling, pool filling, pressure washing or outdoor car washing.
Consumption had run between 1.31 and 1.48 billion litres of water per day prior to the stage 3 declaration, but water use dropped to 1.24 billion Tuesday and 1.19 billion Wednesday.
That’s just under a new regional target of no more than 1.2 billion litres a day that officials estimate should stretch the water supply all the way to November, even if not another drop of rain falls until then.
“We are seeing positive results with stage 3,” said Metro utilities committee chairman Darrell Mussatto. “Obviously cooler weather is our friend, rain is our best friend and people are making a difference.”
Tougher water rules were imposed because the reservoirs have continued to decline significantly through July, reaching 69 per cent capacity this week, much earlier than normal.
The move to stage 3 came after Metro engineers retooled their estimates of how long the water could last if the extreme dry conditions persist for months.
Original calculations were based on the driest year previously on record, which still had some rain in the summer.
“We changed the model last weekend,” Mussatto said. “We said forget the driest year. Let’s pretend there’s no water between now and the end of October. What does that look like?”
That scenario is estimated to be a one-in-750-years incident, Mussatto said, adding that’s how the 1.2 billion litre daily maximum was reached, as well as the decision stage 3 was required to reach it.
Metro has approval from B.C. Hydro to buy up to 62 billion litres of water from the Coquitlam reservoir – more than usual at an additional cost of $862,000 – but Mussatto stressed that volume is already factored into Metro’s supply estimates, as is the water stored in high alpine lakes that will be transferred to the Seymour and Capilano reservoirs.
The Coquitlam reservoir is a large water supply, but Metro’s ability to draw from it is currently limited by the height of its intake pipe.
The region plans to build a deeper intake so it can draw more, gaining more capacity to serve population growth in future years, but Mussatto said that will be a multi-year construction project.
Longer term, the region can raise the height of the Seymour dam, but it hopes it won’t have to embark on that very costly project for decades.
The Coquitlam reservoir serves the eastern third of the region, including Surrey, Delta, much of Langley, Maple Ridge and Pitt Meadows.
B.C. Hydro has not been using it to generate power, conserving the Coquitlam source’s water for drinking and sufficient flows for fish survival.
Mussatto said the regional board will likely try to coordinate a more standardized approach between local municipalities to punishing water wastrels.
He said some cities give one letter of warning before fines, while others provide two and some go beyond fines to shutting off water when users defy water restrictions.
That debate is expected in the fall.
As for violations, he said most are out of ignorance, with only a few offenders outright defying the restrictions.
Neighbours have been blowing the whistle on illegal lawn sprinkling, and some businesses and cities have also faced a backlash for continued sprinkling.
Some exemptions are allowed, including minimal watering to maintain school yards, sports fields, golf greens and turf farms.
More metering urged to conserve
Hans Schreier, a soil science and watershed management professor at UBC, said Metro could likely have moved faster to impose tough water restrictions, as some U.S. jurisdictions did, as well as regional districts on the Sunshine Coast and Okanagan.
He said a better approach than expensive water infrastructure mega-projects would be for Metro cities to get serious about metering water in existing homes, not just new construction.
“We have very poor water accounting,” he said, adding modern smart water meters can remotely alert officials to excessive use and fines can issued electronically.
European countries also charge three to seven times as much for water as residents here, he added.