Officials from Boulder County and the Boulder County of Office of Emergency Management held a meeting at LifeBridge Church in Longmont Monday night (March 10) to update residents on the potential threat posed by the spring snowmelt, and to advise them how to prepare and mitigate for the threat of reflooding. Boulder County Flood Recovery Manager Gary Sanfacon and Mike Chard of the Boulder County Office of
Emergency Management handed out color brochures and made a Power Point presentation that were loaded with good information and updates including available resources, contact numbers, housing and human services, road construction, debris removal, email sign ups, family emergency kits/plans, weather radios, vehicle safety, right of entry forms, flood insurance, the FEMA 404 “Buyout Program,” and community recovery grants. All good important information. There were also aerial maps in the lobby showing stretches of the North and South St. Vrain Rivers above and below Lyons indicating almost a hundred sites along the rivers that had been identified as critical for debris removal and stream bank improvement/mitigation, and outlining what mitigation had already been completed, and an anticipated timetable for what work was yet to come. Sanfacon and Chard stressed that we are all in this together, and that everyone should be vigilant and act as the eyes for the community. If you see a problem, call 911 and report it. If a particular site isn’t marked on the map for mitigation, let them know about it. That was the good news.
The bad news is that the snow pack for the various drainages of the St. Vrain River system is currently at 168% to 200+% depending on the specific area. Adding to that Chard informed the group that since the state has been keeping records (1937), this winter is on pace to be in the top five for accumulated snow pack. Unfortunately, another take away from the meeting was that these resources, i.e. debris removal, stream bank mitigation, and the resources available at the “one-stop” Boulder County Flood Rebuilding & Permit Information Center (1301 Spruce Street, across from the Boulderado Hotel) are only available to “unincorporated Boulder County residents impacted by the 2013 flood.” That was a bit of a head scratcher (So why did they invite residents of Lyons to come to this meeting in the first place?). Every time someone asked a question or raised an issue that pertained to something that wasn’t part of unincorporated Boulder County (When is the Sunset Bridge going to be repaired? I live on the border of Longmont and there is a culvert that needs mitigation. What is the current status of the Button Rock Dam, vis a vis sedimentation, debris removal, capacity?), the answer seemed to be, You have to talk about that with the City of Longmont.
So, Dale Rademacher, Director of Public Works for the City of Longmont was called, and he gave the Lyons Recorder some answers to some of the questions area residents have about the Longmont Reservoir, Button Rock Dam, and the Ralph Price Reservoir (named after a former Mayor of Longmont), a.k.a. Button Rock Reservoir.
County Road 80, off Rte. 36 at Shelly’s Cottages, also called Longmont Dam Road has been “winter repaired” to allow emergency access to the Longmont Reservoir (the lower reservoir on the right hand side of the road below Button Rock Dam), which diverts water for Longmont/Lyons drinking water system. Rademacher explained that approximately forty to sixty thousand cubic yards of silt, sand, and rock was dredged from the reservoir to restore it to its pre-flood capacity (Incidentally, some of that dredged material was used to repair the road). The road to, and along the northern border of the Ralph Price Reservoir is being repaired, and work on clearing out the log debris that is located at the inflow of the reservoir should begin in early April and should take about two weeks to complete. Apparently this log jam at the inflow prevented most of the woody debris from actually entering the reservoir. The capacity of the Ralph Price Reservoir is about normally about sixteen thousand acre-feet, and the current level is at approximately thirteen thousand-five hundred acre-feet. Longmont engineers’ best estimate at how much silt, sand, and debris settled in the reservoir as a result of the September flood is somewhere around three to four hundred acre-feet (or about two and a half percent of normal capacity). Options for removing this sediment are being looked into. So, the dam and spillway are intact and functioning normally, total water capacity is fairly close to pre-flood levels, and mitigation for debris removal should begin in a few weeks.
When Rademacher was asked about anticipated release levels during melt off, he explained that the pipe below the dam itself releases up to eight hundred cubic feet of water per second (cfs), and that the spillway, by design, doesn’t release water until the reservoir is full. The spillway has the capacity to release as much as thirty thousand cfs, and Rademacher estimates that at its peak during the September flood, it was releasing about eleven thousand cfs.
So, for those of you who are wondering about the status of Button Rock, that is some more good news. Rademacher said he would be open to coming to Lyons to give a presentation about Button Rock to help allay any lingering concerns the community might have. Maybe we should invite Boulder County officials and residents of unincorporated Boulder County to attend.