Projects / Surface Water Management
AQWC Restoration - Feasibility Study
The objective of this study was to evaluate the suitability and cost-effectiveness of maintaining the Aha Quin West Channel (AQWC) as an open water backwater channel with associated wetlands. Hydrology and sedimentation issues have demonstrated over time that the AQWC site is not self-sustaining and requires frequent and costly maintenance to continue to provide the originally intended function.
- CLIENT
- USBR(sub-consultant to AES)
- YEAR
- 2016-2017
- APPLIED SKILLS
- H&H Modeling: Data processing, conceptualization, & Setup
Design storm simulations
Scenario evaluations - CONSULTING AREAS
- Surface water management
- SOFTWARE
- HEC-RAS, EPA-SWMM5, SWMM5 to SHP, ArcMap, AutoCAD.
Specifics
Models used in this study:
- SWMM model developed for the Manson Wash basin to obtain design storm outflows.
- Existing HEC-RAS model of the Colorado River adjusted to obtain seasonal water level percentiles at project sites.
- HEC-RAS model built to obtain water levels profiles at the AQWC under existing conditions and two proposed scenarios: original design criteria and sustainable design restoration.
- HEC-RAS model to obtain water levels profiles at the offsite mitigation channels.
The proposed scenarios for the AQWC included the dredging to reach two different bottom profiles, a retention basin to reduce sediment load from the Manson Wash ephemeral flows, and a sedimentation basin at the upstream end. An off-site mitigation channel was also proposed. Extend of open water and wetland areas were determined for all cases. A cost analysis at conceptual design level was also conducted.
Outcome
The suitability and cost-effectiveness evaluation of the different scenarios lead to some recommendations that are helping the stake holders in their decisions.