Replace 14 Culverts on the North Escarpment Waterline Access Road

Mesa Verde National Park » Replace 14 Culverts on the North Escarpment Waterline Access Road » Document List

Mesa Verde National Park is proposing to replace 14 culverts located along the Park's waterline right-of-way, located approximately one mile north and west of the Mesa Verde National Park boundary, along the North Escarpment, Montezuma County, Colorado. These culverts provide a drainage path within intermittent drainages that pass underneath the Park's main waterline and access road. These 14 non-historic culverts were constructed during the Waterline Replacement Project Phase III, in 1992. The replacement of the 14 culverts will take place on BLM, State of Colorado, and private land.

These drainage structures protect the main 8" waterline that traverses the Montezuma Valley floor from the Park's Water Treatment Plant west to the base of the North Escarpment. These culverts protect the pipeline from damage caused by flooding. The waterline is the Park's only water source and is critical for all operations, visitor services (585,000 annual visitors) and fire protection.

Most of the existing culverts are 28 years old and are corroded, deteriorated, and in some cases damaged beyond repair. Poor designs and improper channeling cause frequent plugging and extremely high maintenance as they do not allow debris to pass through the structures. They are not draining effectively and are contributing to erosion of the access road and embankments. If the structures plug during high water flooding events, the Park's waterline could be destroyed, causing the water supply to be lost, contaminated, and the park could be closed until repairs are made.

The intermittent drainages have been flooded and cleaned so many times, that it will be necessary to realign the drainages into and out of the culverts. The upgraded aprons and concrete head walls will prevent this from happening in the future.

The project is divided into four smaller projects for the purposes of contracting and funding. The work will be conducted between the summer of 2020 and the summer of 2022.

The scope of work for all 14 culvert replacements includes the following:

• The area of direct ground disturbance includes all staging areas, plus 25 ft around each culvert to maneuver equipment. The maximum depth of excavation is 10 feet.

• Impacts include compaction and surface ground disturbance within 25 ft of each culvert resulting from driving equipment in the area. Compaction and ground surface disturbance in the staging areas. Excavation up to 10 feet to remove existing culverts and install new culverts.

• Culverts and staging areas are located on Bureau of Land Management land, State of Colorado land, and private property. The Project Leader will be consulting and coordinating with property owners to time the construction. The project will have to be scheduled around when the fields are used for cattle grazing and hunting season. Equipment and materials to be used on the culvert replacement project will be placed on the staging areas.