UP above the North Shore, it's raining in the mountains. Clouds hang low, drifting over the dark shapes of the ridgelines and the trees that stand there like sentinels.

At the Cleveland Dam, water rushes over the spillway, frothing and billowing, its wash of white noise thundering against the damp canyon walls. Beyond the dam, rain stirs the lake's grey-green surface.

The Capilano watershed is one of three - along with the Seymour and Coquitlam - that supply water to more than two million people, half the population of the province. Each watershed is 20,000 hectares, the equivalent of 50 Stanley Parks, rising from just above sea level to between 1,500 and 2,000 metres in elevation.

Streams that begin as slow trickles merge as they plunge downhill, finding other tributaries, taking on names like Sisters and Hesketh creeks before joining the Capilano River. The river changes from a quiet burble in summer to a roar in winter. Sometimes the water gets so high it touches the stringers of the old railroad bridges.

All three watersheds are closed to the public and controlled by Metro Vancouver under 999-year leases. It's an arrangement envied by other jurisdictions.

"There are people in the province who come to us and say 'How'd you get that?" says Bob Cavill, watershed division manager for Metro Vancouver. The secret? "It occurred 80 or 90 years ago."

What happens in the watersheds has always loomed large over the Lower Mainland. There's a lot at stake here.

While water itself is plentiful and free for three-quarters of the year, the systems needed to store it, filter it and distribute it aren't.

The water utility has the largest budget of all Metro Vancouver departments, coming in around $224 million this year, including debt servicing costs - about a third of Metro Vancouver's total expenditures. Water infrastructure projects run to the hundreds of millions.

But water isn't something most people think about in Vancouver, unless there's a problem.

. . .

"In at one. Cap Main." As he heads into the Capilano watershed on a still-sunny day, past the security gate at the Cleveland Dam, Cavill calls in his position over the truck radio. Not many people have spent extensive time over two decades in the watersheds, but Cavill is one of the few.

About 40 people work in the watershed permanently - more in summer. They do everything from replacing road culverts to stabilizing slopes to fire protection.

Water storage in the reservoirs is constantly fluctuating. At their lowest, in mid-October this year, the three reservoirs dipped to just below 60 per cent of full. Thanks to a soggy June and a better-than-average snowpack, that was well within normal levels.

Capilano Lake reservoir holds 53 million cubic metres of water. But beyond the main reservoirs, the watersheds also contain a series of other lakes and rivers, crucial to maintaining supply in dry months. When water levels dip in the summer, Metro staff release water from high alpine lakes including Palisade Lake that feeds the Capilano River, and Burwell Lake and Loch Lomand that supply the Seymour. "They are absolutely essential to our water supply," says Cavill.

Another essential component of the water system is gravity, which is why the North Shore mountains play such a large role. In places without that advantage, utilities face large power costs to pump water, sometimes over long distances. Or as City of Vancouver Mayor Darrell Mussatto, chair of Metro Vancouver's utilities committee puts it, "Gravity saves us millions."

In the Capilano watershed, you don't have to go far into the woods to see history. Near the top of Capilano Lake, the remains of an old aqueduct snakes through the trees, leading to a clearing with concrete settling ponds. A large moss-covered gear sits next to a fern. "This was the water supply to the mid 1950s," says Cavill.

When the system was operational, there was a screen to keep the logs out of the pipes and a furnace to thaw the ice buildup in winter. "They mucked it out by hand," said Cavill. "There was no water treatment. It was just a direct hit of raw water."

The Vancouver Water Works company built the first water system on the Capilano River for a cost of $300,000, ultimately delivering water from the Capilano to taps downtown in March 1889. Within months, there was trouble, including leaks, broken mains and an annoying tendency for ships to slice open the pipes in the First Narrows. The public was not amused, and the young City of Vancouver soon acted on a clause allowing it to buy the waterworks.

But other threats to the water supply soon materialized. Around 1904, logging companies moved in to the Capilano watershed.

The Province newspaper of the day warned logging plans of some big U.S. timber companies would make "Vancouver's water supply look like an Arizona trout stream in summer."

Alarmed, city politicians went to Victoria and asked for a 999year lease on the watershed "with a view to keeping the city's water supply in its pristine purity." The province turned them down.

In the early 1920s, the Capilano Timber Company logged the river valley by railway. There were many escaped slash fires, which poured smoke from the North Shore mountains over the city. Public reaction was instrumental to forming Greater Vancouver's first water district in 1926, with the goal of protecting the city's water supply.

The 999-year lease was granted a year later. "Considered as economic resources, it is not open to debate that the value of these watershed areas lies first in their importance as sources of pure water supply and secondly as stands of merchantable timber," said Dr. Ernest Cleveland, the first water commissioner. The water district soon flexed its new political muscle, buying out the interests of logging companies and other private landowners in the river valley or otherwise persuading them to leave.

"It wasn't just a slam dunk," said Cavill. "There were landowners up here, influential people. Apparently those early years were quite raucous in terms of lawsuits."

Today, protection of the watersheds remains key. The roads in are gated and monitored, but there are people who sneak in. "Occasionally we find them and take them back out," says Cavill. Hydro crews need permits to work in the watershed. Herbicides and pesticides are banned.

A few years ago, the RCMP asked for permission to drive into the Coquitlam watershed to avoid a lengthy water route up Indian Arm to look for poachers. The water board turned them down.

Built in an era of post-war mega projects, the watershed dams addressed a fundamental problem: a water supply that was abundant for eight months of the year, but which dwindled as rains tapered off in the months with the highest use.

As its population has grown, so has Greater Vancouver's water consumption. Our overall use of a billion litres a day is more than 25 per cent higher than it was 30 years ago. About 60 per cent of that water is used residentially, the rest by business and industry. At the height of summer, that number can double, to daily water use of between 1.5 and 2 billion litres.

Things could be worse, however: While overall use is growing, per capita water use has been steadily falling. In the mid 1980s, before conservation dented the public mindset, Metro Vancouver users flushed, sprinkled and showered their way through 743 litres per capita daily and almost double that in summer. In contrast, today's average per-capita water use is about 471 litres - a drop of 37 per cent.

Part of the change has come through regulation - like sprinkling restrictions, first adopted in 1992, and rules requiring new buildings to install low-flow toilets.

Other societal factors have also played a part. Compared to earlier decades, "There are fewer people living in big-yard single-family homes," says Stan Woods, senior engineer in the utilities planning department. "The average resident lives in a multi-family unit and doesn't have a yard to water."

Water metering has been adopted in relatively few communities, despite evidence that price influences behaviour.

For many municipalities, the cost of retrofitting homes with meters has proved a deterrent, particularly given Metro Vancouver's low bulk water rates of between 45 and 56 cents a cubic metre.

West Vancouver, which supplies about half its water from its own reservoir at Eagle Lake, is an exception.

Prior to 2006, "We were known as being water hogs," says Ray Fung, director of engineering and transportation for the district.

The top sixth of the communities users were consuming over 50 per cent of the water, a fact that also helped to drive the change.

Not everyone was pleased when the first metered water bills arrived, however. "People always feel they use less water than their neighbours."

But in the five years since meters were installed, consumption has dropped by 25 per cent, to 546 litres per capita last year.

On the west side of the Capilano watershed, a spur road near Hesketh Creek climbs to over 600 metres. From a high point here, you can look across the valley to Crown Mountain and to slopes around the Eastcap Creek that were watershed battlegrounds in more recent history.

Before the Seymour filtration plant opened in 2010, turbidity - essentially suspended sediments that caused cloudiness and lessened the ability of chlorine to disinfect - had long been a problem in Vancouver's water supply. Steep slopes, combined with light glacial silts and winter storms, had a habit of turning tap water murky.

But as a group of environmental activists began to point out in the mid 1990s, natural geology wasn't the only factor at work in the watersheds.

While the watersheds had been closed to fishermen and hikers, from the mid 1960s to mid 1990s, the water district turned its back on the warnings of the earlier watchdogs and set to work logging in its leases. It was a profitable venture. A patchwork of clearcuts sprang up on the slopes and more than 300 kilometres of roads were built.

Not many people made it their business to know what was going on, says activist Will Koop, including politicians charged with protecting the water supply. Among staff, a belief that forests needed to be "managed" and that the best way to manage them involved cutting down old growth trees dominated.

Koop didn't share it. Nor did Elaine Golds, a member of the Burke Mountain Naturalists, who first questioned watershed logging after a landslide in the Seymour watershed turned her tap water to mud.

Koop and Golds started researching, attending meetings of Greater Vancouver's water board and asking questions. They met with a frosty reception. "Initially, we were discounted as hippies who hugged the earth," says Golds. "Politicians do tend to believe what their staff tell them. It was a closed shop."

But environmental activists persisted. When a large slide happened near a clearcut and logging road in the Seymour watershed, the Western Canada Wilderness Committee flew in by helicopter to document the damage.

Koop took to spotting Capilano slides from the Grouse gondola with binoculars, then sneaking in to the watershed with a video camera to document what he found. Politicians weren't happy with Koop's unauthorized forays or his presentations. But over time, they found the arguments of environmentalists impossible to ignore.

By 1994, then-councillor Ernie Crist from the District of North Vancouver sputtered in one meeting that he was "disgusted" plans to log in the Seymour watershed were still being presented and charged the staff reports were "proof the GVRD is controlled by a forest industry which has ruined the city's water supply."

By the mid 1990s, the public mood was clear. Politicians halted logging in the watershed. The option for future logging was cancelled in 2002.

"It was a long struggle. Nine years of my life almost," says Koop today. "I'm glad I did it. It's very critical to have somebody watching these things."

Back across the river valley near Eastcap Creek, Rodgers Lake sits at the end of the road. It's a high point near where the Lynn, Seymour and Capilano drainages come together along the mountain ridges.

It's cool up here, even in summer, the result of subalpine cold air being forced down to create an unusual microclimate. In summer, a waterfall cascades down through a valve on Palisade Lake, eventually running through Rodgers Lake, Palisade Creek, Eastcap Creek and down to the Capilano.

By November, it will start snowing.

Both the alpine lakes and snowpack are key to the region's water supply.

"We're good for a few decades, given our current situation," says Cavill.

By 2070, however, waters use is expected to grow to an average of two billion litres of water a day. That's prompted engineers to think about where the water will come from.

The first and most likely solution will be to take more water out of the Coquitlam Reservoir, which has more than twice the storage capacity of the Seymour and Capilano. Currently only about 25 per cent of Coquitlam Lake is used for drinking water. The lion's share goes to B.C. Hydro's power generation. But negotiations with the power utility are much preferred over other solutions.

Beyond that, raising the height of the Seymour Falls dam by 20 or 30 metres remains the region's fallback plan. That would increase the reservoir's volume by five times, to 169 million litres. But it would also cost hundreds of millions of dollars and flood 250 hectares of forest.

Just how soon such solutions will have to be considered depends on many factors, including the wildcard of climate change. Rising temperatures could bring more intense winter rainstorms, a smaller snowpack and drier summers, among other changes. All of those will be problematic for Vancouver's water supply, especially in combination.

Snowpack levels are monitored monthly during winter in the high elevations of the reservoirs. "We like the snowpack up here," says Cavill. "It's like slow release capsules."

Continued drops in summer consumption patterns mean there's less panic about water supply than there was even a few years ago. But those who manage the resource are always thinking ahead.

"We like to plan ahead 50 to 100 years," says Cavill. Mussatto says today's watershed managers owe a debt to those who came before them, who recognized the value of Vancouver's water sources.

"Sometimes we point back in history and say we did this wrong and this wrong," he says. "But the people who came before us, who protected the watershed, were visionaries."

jseyd@nsnews.com