Snowpack and the Alpine LakesSnowpack and the Alpine Lakes<div class="ExternalClassCA6FAD117AD24C35899FD414F8911284"><p>Ever wonder about the significance of the snowpack on our water supply? Most years, the North Shore Mountains receive a healthy amount of snow, which gradually melts in late spring and flows into the reservoirs, supplementing the spring rains. In years when the spring rainfall is lean, the snowpack takes on added importance in replenishing the reservoirs. </p><p>Metro Vancouver’s Watershed Protection staff keep a close eye on the snowpack –from the beginning of January to mid-June, they travel on foot and by helicopter into the remote wilderness to measure the snowpack. They take samples from five different sites to measure snowpack depth and density, to determine the snow-water equivalent – the quantity of stored water in the snow that will be available for the reservoirs in spring and summer. The 40-year average for the highest site is 4 metres snow depth. </p><p>Snowpack levels during the 2015 drought were the lowest on record, since data collection on Grouse Mountain began in 1936. Four of the five measurement sites were snow free by March 1, an unprecedented occurrence. While snowpack levels this year were healthier than in 2015, they were still 30% of the historical average, as of June 1. This year’s El Niño weather cycle resulted in a higher freezing level than usual, with considerably less snow at lower elevations. Hot April days also contributed to a quicker snowmelt, although this was offset by lower temperatures and rain through late spring and into early summer.</p><p>Metro Vancouver’s reservoirs are also bolstered by water from three alpine lakes: Burwell Lake, Palisade Lake, and Loch Lomond. These feeder lakes are typically used in mid-summer to supplement the supply of water available in the Capilano and Seymour reservoirs. The water from these deep, cold lakes is particularly high quality and contributes to an increase in downstream aquatic habitat, particularly during periods of drought. </p><p>Like the main storage reservoirs in Capilano, Seymour and Coquitlam, the depth of the alpine lakes is carefully monitored and managed. Only about two-thirds of the available water is normally used throughout the summer, to ensure that the lakes will completely refill and be available to feed the reservoirs in the following year. </p><p>In years such as 2015 with poor spring rainfall, the snowpack and the alpine feeder lakes take on added significance as contributors to our drinking water supply. While our reservoirs consistently provide adequate water for our growing population, it’s important to remember that this supply is linked to our own demand. By using our water wisely, especially in the dry summer months, we can ensure that the water supplied by rainfall, snowmelt, and the alpine lakes continues to meet our needs.</p><p>You can watch a video about snow pack monitoring <a href="/media-room/video-gallery/issues/218579278" target="_blank">here</a>, and accessing the alpine lakes <a href="/media-room/video-gallery/issues/219034528" target="_blank">here</a>. Metro Vancouver also posts <a href="/services/water/sources-supply/reservoir-levels/Pages/default.aspx" target="_blank">weekly reservoir storage levels</a> from May to October, when rainfall is lower and the regional demand for water is higher. </p></div>|#2d395db4-59c2-4bcd-8cf3-118afd214b4e;L0|#02d395db4-59c2-4bcd-8cf3-118afd214b4e|Issue 23;GTSet|#d14ffe11-45dc-48fb-8684-ff109cf15a74<div class="ExternalClass0F6B71E18DD949439B43FFC61F74CE5E"><p>​Looking to the North Shore Mountains, we can see the majority of the visible snowpack for 2015 is melted. What does this snowpack mean to our water supply? And how is it monitored? Find out here…</p></div>0