Niwot Ditch Diversion and Fish Passage Design | Longmont, CO
CLIENT: Trout Unlimited
PROJECT TYPE: River Restoration, Fish Passage Design, Diversion Structure Design, Water Rights
PROJECT LOCATION: St. Vrain Creek, Longmont, Colorado
WaterVation developed stream restoration and fish passage design plans between two ditch diversions on the St. Vrain Creek that were damaged during the September 2013 Flood. Project objectives consisted of removing a push-up dam, providing continuous fish passage, preserving existing water rights for the ditch diversions, restoring the diversions, and implementing a low maintenance natural channel restoration design for a total stream length of 1,500 feet.
The existing push-up dam was approximately 12 feet tall and was replaced with five mild-sloping riffle structures over 1,500 feet of the St. Vrain Creek. Two-dimensional hydraulic modeling was performed to ensure in-stream hydraulic conditions are suitable for fish passage and to confirm ditch diversion functionality. Sediment transport modeling was performed to ensure the proposed design will remain stable and require low maintenance. This project had seven different stakeholders, three of which were private landowners, making up-front objective setting critical for successful project completion. The design team performed detailed stream and geomorphic surveys to facilitate alternative and design development. A total of 3 public meetings were held to obtain landowner input and approval for design and future construction phases.
Stakeholders
U.S. Fish & Wildlife
Colorado Parks & Wildlife
Boulder County Parks & Open Space
South Flat Ditch
Niwot Ditch
Services
· Fish Passage Design
· Irrigation Ditch Diversion Design
· Water Rights Impact Evaluation
· Natural Channel Design
· Dam Removal
· Aquatic & Terrestrial Habitat Restoration
· Sediment Transport Modeling
· 2D Hydraulic Modeling
· Floodplain Permitting
· CM Services
Services; Stream Assessments, River Restoration, Natural Channel Design, Fish Passage Design, Permitting, Construction Oversight
