A sweeping city drainage project at City Park Golf Course (CPGC) that will remake the landscape and bulldoze about 260 trees has survived a legal challenge that put the controversial plan on trial.

Denver District Court Judge David H. Goldberg on Thursday issued a decision in favor of city parks officials, including parks director Allegra “Happy” Haynes. He rejected the arguments of a group of activists who have claimed that installing a huge stormwater detention area on designated parkland would violate the city charter.

But that doesn’t mean Goldberg dismissed their concerns.

In his 24-page ruling, issued two months after a four-day bench trial in August, Goldberg wrote that “the loss of a mature (tree) canopy is materially detrimental to the habitat and the neighborhood,” that the project could imperil the course’s historic status and that he was loath to see it closed for construction.

But the judge ruled that city officials were within their right to use the golf course for the drainage project, which is part of the city’s larger Platte to Park Hill stormwater plan. He also credited a city engineer’s expertise in storm drainage issues, giving it more weight than the plaintiffs’ critical experts.

Goldberg didn’t wade into the debate over connections between the project and the state’s controversial $1.2 billion expansion of Interstate 70 through northeast Denver, which opponents argue is the city’s true motivation.

“Though the reconfiguration of CPGC may be a thinly veiled subterfuge to pave the way for new construction plans on I-70 and along the I-70 corridor, consideration of the various rationales and funding mechanisms for the project is beyond the scope of this court’s charge due to the applicable standard of review,” he wrote early in the decision.

The Denver residents who challenged the plan could still appeal his ruling.

But for now, with trees already marked for removal — some opponents called their impending cutting an “arboreal holocaust” in recent weeks — the course is set to close Nov. 1, with ground work beginning soon after. The golf course will close entirely for up to two years.

“To ensure that Denver’s parks are protected in the future, we may need new laws or new elected officials,” said Aaron Goldhamer, the plaintiffs’ lead attorney, in a statement Thursday afternoon. He said his clients were considering their appeal options.

In a separate case that’s still pending in U.S. District Court, Goldhamer is among attorneys challenging the I-70 project based in part on its connection to the Platte to Park Hill plan.

Denver’s Department of Public Works, which is overseeing the project, said in a statement Thursday in response to the new ruling that the golf course redesign project would provide better flood protection for some areas of the Montclair Basin as well as an improved course for golfers.

“As the city showed during the trial, harmonizing stormwater management and recreation in urban parks is a best practice that Denver, and cities around the world, are utilizing to create great public spaces that provide a multitude of environmental benefits,” the statement says.

Public Works spokeswoman Nancy Kuhn said that of the 260 trees pegged for removal, about 55 percent are younger, with diameters of less than 12 inches. The project will not disturb trees along the golf course’s perimeter, she said, except for five trees near the entrance; several large historic groves inside the course also will be retained, she said.

Goldhamer’s office represented former Colorado Attorney General J.D. MacFarlane and seven other Denver residents who opposed the golf course plan — several of whom were gathered, along with other opponents, in the City and County Building on Thursday for a scheduled 2:30 p.m. court hearing on Goldhamer’s now-moot request for an injunction blocking construction.

Until they arrived, they didn’t get word that the trial ruling had come out about two hours earlier, resulting in the court calling off the hearing. Christine O’Connor, one of the plaintiffs, said the group was frustrated at the timing, as well as in the decision itself.

“We’re all pretty disappointed that the court didn’t put some kind of limits on the power of the executive director of Parks and Recreation,” O’Connor said via phone.

The lawsuit, filed last year, targeted one of four main components in the Platte to Park Hill plan to improve stormwater drainage in parts of east and northeast Denver.

Carrying an estimated price tag of $267 million to $298 million, the project includes large detention areas, new pipes, a drainage channel along 39th Avenue and a new outfall on the South Platte River at Globeville Landing Park.

For City Park Golf Course, the city has awarded a $44.9 million design and construction contract to a team that is redesigning the entire course to incorporate a stormwater detention area into the landscape of the western third.

During and after heavy rainfall — up to a 100-year storm — the course would take on water for up to eight hours to slow the runoff’s flow toward the river.

The plan requires the removal of about one-third of the course’s trees, to be replaced by new ones on the course and elsewhere that will take decades to mature.

As the trial unfolded Aug. 21-24, the plaintiffs and their attorneys argued that such a large and invasive project would violate the Denver city charter’s rule that designated parks can’t be used for nonpark purposes. They also cited zoning rules.

“Although plaintiffs strongly disagree with the project, they have not presented clear and credible evidence that defendants have improperly discharged their duties,” Thursday’s ruling says. “As a result of the presumption of regularity of the official acts of public officials, the court accords deference to defendants’ determinations with respect to parkland generally, and CPGC specifically.”

During the trial, city attorneys argued the project was allowed because it wouldn’t change the core function of the land as a golf course.

Goldberg’s decision noted that Haynes, the parks director, said in her testimony that Denver has more than 500 acres of parkland that serves as detention areas, though “a significant portion of the acreage is comprised of lakes.”

Here is Thursday’s court ruling: