Documents providing design work are compiled here. They can be seen referenced throughout the main documents. Their purpose is to document the process by which the final design for flood control of the wash was obtained.
All designs developed, including the final designed are briefly outlined in the attached pdf. It is borrowed from the main presentation.
A total of six alternatives were selected to resolve the flooding issues in Switzer Wash. These are the creation of natural channel between reaches 1 and 2, this same natural channel and an culvert that bypasses the neighborhood, the creation of upstream and downstream detetion basins, the creation of upstream and downstream detention/LID basins, wetland developmelnt, and an upstream basin with natural channel modifications.
These alternatives were compared against each other in a decision matrix that used five criteria as the basis of judging. The critera used were the design cost compared to the benefit, environmental and social impacts, operation maintenance, area needed, and individual appeal. Cost vs benefit received higher scores for being comparatively less expensive than other designs to develop while also resolving the flooding problem. Social and environmental impacts gave more points to the designs that minimized negative impacts in those areas while promoting positive impacts. Operation maintenance costs was created seperate to implementation costs to determine long term expenses, and the desings with less extensive maintenance were scored higher. Total surface area needed to implement the design rewarded more points to the designs that took up the least amount of space. Appeal was an individual, personal interest in the design, and the ones more liked by the team received higher scores.
The natural channel modification with the neighborhood culvert bypass was chosen as the final design after considering these criteria. Additional detail on the process can be found in the Final Report.
The output values for the proposed natural channel modifications and its dimensions are provided in the attached pdf.
To determine if the final design was within the City of Flagstaff code, the modified natural channel was modelled in full using the 100-year storm flow. These values were found to be within the code standards. The exact details of these numbers compared to the code can be found in the Final Report.
The output values for the proposed double barrel culvert and its dimensions are provided in the attached pdf.
To determine if the final design was within the City of Flagstaff code, the culvert was modelled in full using the 100-year storm flow. These values were found to be within the code standards. The exact details of these numbers compared to the code can be found in the Final Report.