The developer of the controversial Hogan-Pancost project has withdrawn a request for annexation to the city of Boulder.

Neighbors of the proposed development in southeast Boulder long have expressed concerns that the project would make flooding worse.

In a letter to city planning officials, developer Michael Boyers said the severity of this month's flooding in Boulder and across the Front Range made this an inappropriate time to pursue the project.

"In light of the historic flooding our community has experienced and the ongoing need to refocus city resources on flood recovery and other flood-related issues, and after discussion with you and other staff members, we have concluded that it would be most appropriate to defer consideration of this annexation to another time," Boyers wrote in the letter to city planners.

Boyers said in the letter that the flooding provides the opportunity to study and analyze the actual impact on the property, rather than models and projections. However, doing that analysis will take a year or longer.

Boulder Planner Karl Guiler said the annexation application is considered closed. If and when Boyers refiles, the approval process will start from scratch.

The city's Planning Board unanimously rejected the project in April after 14 hours of testimony and debate spread over three days.

The plan for the 22-acre site called for construction of 121 homes near South Boulder Road and 55th Street, including 50 "congregate-care" senior housing units, six affordable duplexes, two affordable single-family homes and 63 market-rate single-family homes.

The City Council was scheduled to hold a public hearing and vote on the annexation request at a special meeting Oct. 3.

The annexation request was made without a site plan, which is unusual and had raised concerns from some council members.

Jeff McWhirter, a southeast Boulder resident who has spent more than a decade fighting the Hogan-Pancost development, said that in some ways, he and other opponents were hoping for closure with a rejection of the annexation request next week. At the same time, he was also concerned there might be enough votes on the council for annexation to go forward.

However, McWhirter agrees that more study is needed.

"This is the right decision right now," he said. "They have the right to reapply, but they can and should do more study."

McWhirter said opponents will also lobby to move the property into Area III of the Boulder Valley Comprehensive Plan when the plan is updated in 2015. With the exception of the Planning Reserve north of Boulder, Area III properties are ineligible for annexation.

McWhirter posted photos online of the Hogan-Pancost property with significant surface water on it on the morning of Sept. 12, before a second night of heavy rain further overwhelmed area drainageways.

He cautioned that this month's flood does not appear to have been a 100-year flood along the South Boulder Creek. The Keewaydin neighborhood was built without storm sewers and frequently sees flooded basements and running water in the streets during heavy rains.

"Would development on the HP site have made our recent flood worse?" McWhirter wrote in a blog post on the flooding. "I think the answer is yes. Where now most of the rain falling on the property stays in place and soaks into the 20 acres of pasture, after development all local drainage on the site is routed to the northwest towards the existing homes."

Flood engineers hired by Boyers have said the flood impacts can be mitigated.