Sierra Club member raises Little Walnut Creek bypass tunnel dewatering concern to Environmental Commission

Craig Naser, speaking as a Sierra Club member during the Environmental Commission’s public communication period on June 4, reported on observations he and other members took at Little Walnut Creek. Naser described a bypass tunnel under Mearns Meadow designed to carry flood overflow and said recent photographs and video show water coming up through joints in the bypass tunnel and appearing to dewater the surface creek downstream.

Naser said he attended public meetings about the bypass project 15 years ago and noted the project-sized escalation from earlier cost estimates. He presented a sequence of photographs and a video taken that afternoon showing low surface flow in stretches of the creek, algae where flow is reduced, and stronger discharges at the tunnel outlet. "The water is coming up in the bypass tunnel, and it appears to be dewatering the creek," he said, and added that he had "talked to Watershed about it and it's the project isn't completed yet." Naser requested attention from the commission and staff to the matter.

The chair moved on to agenda business after the public comment period; the transcript records Naser’s remarks but does not include a substantive staff response or commission direction on the record during that meeting. Watershed staff were present for the rest of the agenda and Watershed Protection Department staff previously presented other items at the same meeting. Naser characterized the condition as not intended operation for the tunnel and urged follow-up; no formal action, vote, or referral was recorded in the transcript on June 4 specific to the bypass observation.

What is known from the comment and presentation: - The bypass tunnel is along Little Walnut Creek and passes beneath Mearns Meadow; Naser said part of the creek’s origin is under the Q2 Stadium area. - Naser provided photographs and a video taken the afternoon of June 4 showing variable surface flows and a concentrated discharge at the tunnel outlet. - Naser reported he has discussed the issue with Watershed staff and that the project contractor indicates the project is not complete.

What was not resolved at the hearing: - The transcript does not record a Watershed staff technical explanation, corrective action, or a formal referral by the commission for further investigation on June 4. - No formal vote or motion regarding the bypass tunnel was recorded in the meeting minutes portion of the transcript.

Next steps recommended (noted for clarity, not recorded as a commission action): The commission or Watershed Protection Department could verify the site conditions documented by the commenter, confirm whether the observed flow matches design intent or indicates an unintended dewatering pathway, and, if needed, track corrective actions or contractor repairs through Watershed project management and permit compliance procedures. The transcript shows the comment was submitted and heard during public communications but did not result in a recorded direction at that meeting.