As rain continued Sunday, Barker Reservoir reached capacity and spilled over at about 1:45 p.m., but it posed little concern for emergency officials because the runoff only slightly increased the flow in Boulder Creek.
Barker Reservoir's system was well able to handle the "fill and spill" because it's something that happens every spring during snowmelt runoff.
Officials estimated Boulder Creek flows would increase by about 100 to 150 cubic feet per second between 7:45 p.m. and 9:45 p.m. because of the spillover.
Boulder Creek now is flowing at 800 to 1,000 cfs, so the extra water from Barker Reservoir should have minimal impact, officials said. By comparison, the creek was rushing at 5,000 cfs late Thursday night.
Even with the extra reservoir runoff, Andrew Barth, a spokesman for Boulder emergency operations, said officials aren't concerned about Boulder Creek spilling over.
Officials on Sunday also monitored Union Reservoir in Longmont, Button Rock Reservoir west of Lyons and Wonderland Lake in Boulder and said the systems in place were working.
"The dams and spillways are functioning as designed," according to an update posted on the emergency management website. "Seeing water in the spillway is normal during times of heavy rainfall or runoff. As always, stay away from moving water and do not try to enter any flooding areas."
Baseline Reservoir, which holds water for the city of Lafayette, has seen its level drop by about 4 to 6 inches since Saturday.
Lafayette spokeswoman Debbie Wilmot said workers shut off an inflow gate that had been letting spillover from Boulder Creek enter the reservoir, while at the same time opening a gate at the other end to let out water and ease pressure on the dam. She said the reservoir's spillover function is working well.
Wilmot said crews have been out today fortifying the "base and face" of the dam at Baseline Reservoir to ensure it holds up as rain continues to fall.
"Everything looks good out there," Wilmot said. "We feel that even with the rain, things should be good."
Contact Camera Staff Writer Brittany Anas at 303-473-1132 or firstname.lastname@example.org or Twitter.com/BrittanyAnas.