95th Street partially closed until December

Phase 2 of the North 95th Street Reconstruction and Flood Resiliency Improvements Project began on Monday, Aug. 26. Expect closures in both directions 24 hours a day, seven days a week on 95th Street between Lookout Road and Valmont Road. The construction zone will prohibit motor vehicles, cyclists, and pedestrians from entering.

Residents living along 95th Street will need to access their homes from Lookout Road if living north of Boulder Creek, and from Valmont Road if living south of Boulder Creek. There will be no through traffic during this closure, which is expected to last through December 2024.

The purpose of the improvement project is to reconstruct North 95th Street between Valmont Road and Lookout Road to protect the properties in this area, the road, and the open space from damage caused by flooding. The complete project, which stretches from Lafayette to Longmont, is part of a multi-year, ongoing effort by the Boulder County Public Works Department.

Flooding from Boulder Creek in both 2013 and 2015 flowed over 95th Street causing significant damage to the roadway and utility infrastructure. In September 2013, the Colorado floods were a result of rainfalls that began as moderate, but quickly worsened, causing widespread flash flooding. During this time, the stretch of roadway between Lookout and Valmont Roads remained closed for more than three weeks, due to 95th Street going underwater, and the time it took for the water to recede.

The project's goal is to protect the roadway from flooding, while also ensuring the road will remain intact should flooding events reoccur in the future.

The design of the project will include six large reinforced concrete box culverts that will carry excess flood water during 5 and 10-year storms. They will remain dry most of the time, providing wildlife that travel along the creek corridor with safe passage under the road.

In addition to the concrete boxes, 95th Street will be raised, creating a way for water to flow over the road during events larger than a 10-year flood. Erosion resistance will be engineered along the downstream edge, allowing stability as water flows over the road.

In addition to the floodplain improvement aspect of the project, the road itself will also be reconstructed. The current width of the road will remain unchanged, in addition to its five-foot shoulders. There will be changes to the vertical grade to improve safety which will also reduce noise from vehicles speeding up and slowing down on the hills. The project also includes the addition of a northbound left-turn lane at Gunbarrel Ridge Road.

Boulder County Public Works aims to respect the open space value and agricultural value of the Boulder Valley Farm operation. Not only will the project protect the farm property during flood events, it will also enhance the ecological value by managing flood waters and improving storm drainage across the road.