Nobody can say exactly how many, but trees in Balboa Park are dying, according to park advocates and city officials.

Years without hard rain have weakened the trees, many of which do not belong in this climate to begin with. Now, the drought is making that painfully clear.

The city, which operates the park, is working to save some of the trees, mainly those in the heart of the park. The city is going to leave many, however, to die. Casual tourists may not notice anything amiss, if all goes according to that plan.

Even now, park visitors who keep their heads straight ahead may not notice.

Yet, look up. A ring of browning Canary Island Pines by the Sixth Avenue Playground are like a canary in the coal mine and several may die. A grove of redwoods with denuded tops could be mostly lost, according to two park cheerleaders. Century-old eucalyptuses may not make it.

The City Council talked this week about whether they could make room in the city’s upcoming budget to hire an irrigation specialist for Balboa Park. That could help, but it may be too late for some trees that need weeks of rain to survive. Almost nothing can replicate that, especially not with watering restrictions already in effect and more cuts to water use coming.

The city could not quantify the number of tree in peril. It has not taken a census of the park’s more than 15,000 trees since 1998.

Casey Smith, the park’s operations manager, said the city is focused on saving trees in well-trafficked areas and trees that it considers unique, historic, “horticulturally important” or that have been dedicated in someone’s honor.

Parks department workers have dug basins around some trees, including the Canary Island Pines, to try to capture water around the trees to give their roots a deep soak. Because there aren’t irrigation systems in every part of the park, some watering is being done by hand.

Patrick Caughey, a member of the Friends of Balboa Park board who is also a landscape architect, estimated that roughly 10 to 15 percent of the trees he sees on his daily walk in the park look like they’re dying.

“The trees, once they start dying and they go into decline, they don’t come back,” Caughey said during an interview at his office, which is a block from the park, and on walk by the nearby Sixth Avenue Playground.

Besides empathy for the trees themselves, he wondered if the high owners of expensive places along the park would see their property values go down if their view changed from trees to just brown grass and stumps.

The problems have been building for years without hard rains, the sort of rains that trees need. Suddenly, though, the problems are obvious to park supporters and it’s only May. There are now long months of summer ahead. By summer’s end, Caughey predicted, the Canary Island Pines would either be cut down by the city or standing dead.

Betty Peabody, who has volunteered at Balboa Park for 45 years, said park supporters have only recently become aware of how much tree damage there is.

“We need to do what we can do,” she said, “because the park is an icon.”

Redwoods, towering natives of the Pacific Northwest, seem doomed. A grove of them near Highway 163 are brown and sickly. Those that stand are still lucky. Nearby are stumps that preview their fate.

“We’ve lost several of those trees over the years and it’s just not feasible for us to dump a lot of water over there to keep these alive,” Smith, the park manager, said.

The park’s irrigation system uses drinking water, meaning it’ll be subject to new cutbacks mandated by the state. The park can already water only three days a week.

If the park was hooked up the recycled water system – so-called purple pipe water, which is not treated to the same standards as drinking water – the park might have access to more water and might be able to spare more for trees. If that were the case, Smith said, “We would probably be putting more water down than we are.”

But it’s not. The purple pipes don’t reach the park.

There is also no irrigation system in the canyons, where some of the most distressed trees can be found, Smith said.