Construction Cost Estimate
To complete the project, the team completed a construction estimate. The construction estimate focused primarily on new material and some essential equipment in completing the job. Each team member did a quantity takeoff for their dam and estimated the respective equipment usage. After compiling each dam’s takeoff, the total estimate is $1,000,000.
Activity Date:
30 April 2022
Final Dam Designs
The resolution of this project entailed a combination of armoring the dam, increasing the dam top elevation, and replacing the original spillway with either a labyrinth spillway or piano key weir shaft spillways. Lake Stockwell Dam’s design comprised of two piano key weirs, armoring of the dam, and lowering of the spillway by 0.8’. Papoose Lake Dam’s design consisted of an increase in the dam top height and a labyrinth spillway. Upper Aetna Lake Dam’s design involved three piano key weirs, an increase in dam height, and lowering of the spillway by 1’. Lower Aetna Lake Dam’s design included three piano key weirs, armoring of the dam, and lowering of the spillway by 0.8’. These designs were vetted to be most optimal, as they effectively satisfy the safety constraint, while being cost efficient and constructible.
Activity Date:
15 April 2022
Labyrinth Chute Spillway
Through numerous iterations the project team established that a longer weir length would be required for each dam. To accomplish this, spillways were researched and tested to see if they would be adequate for the dam system. One of the spillways that was found to be optimal for Papoose Lake Dam was the labyrinth spillway. This spillway utilizes cycles of a labyrinth to lengthen the effective weir length without having to use a long width along the dam. This spillway structure was found to be about three times more effective than a straight spillway across the dam top. This was the optimal selection for Papoose Lake Dam for two reasons. The first reason being that the dam needed an increase in height and the excavated soil could be reused to achieve this. The second reason was that along the dam top was a dirt trail and not a road so the loss in access across the dam was a tolerable loss.
Activity Date:
30 March 2022
Piano Key Weir Shaft Spillway
The team decided to utilize a combination of a labyrinth spillway and a chute spillway. The inspiration for the unique design came from a Scottish design for the Black Esk Reservoir located in the United Kingdom. This design uses a style of labyrinth called piano keys which greatly increases the effective length of the spillway for the chute. Displayed in the Figure is the top view, side view, and cross-section view for the spillway. This shows the piano keys around the rim of the chute which has a much greater perimeter than if we had used a circular perimeter. This increased perimeter allows for more flow to enter the spillway structure thus alleviating the problem of a large influx of water into the reservoir.
Activity Date:
11 March 2022
Alternative Spillway Research
An objective set by the team was to manage the precipitation by manipulating the spillway design. The current spillways are inadequate in design and to resolve this issue, the team decided to try drop box spillway structures. The advantage of this design is that it increases the length of the weir which is the critical design parameter. The team is experimenting with using multiple varying sized spillways and alternative spillway designs. One alternative design the team is researching into is the labyrinth spillway. This spillway maximizes the effective spillway length while minimizing the width of the box. Thus, the zig-zag structure allows for more weir length instead of using a straight edge for the box.
Activity Date:
25 February 2022
Spring Dam Design
The team was tasked with taking an individual approach to redesigning their dam. The goal was to produce three sufficient, unique designs to resolve overtopping due to the PMP. The team’s first design goal was to create a dam that would not overtop and would have an increased height. The second design included a combination of increasing the height but mostly increasing the spillway. The third design allowed for reasonable amounts of overtopping and the armoring of the downstream fascia with concrete. Once the designs are completed, a construction estimate will decide which design is the most feasible.
Activity Date:
15 February 2022
Engineering Services Cost Estimate
The engineering services cost estimate was calculated for the fall and spring semester using the tasks on the schedule. The fall semester hours were recorded as the team progressed through each task. The spring semester hours were estimated from the fall semester's productivity in accomplishing similar tasks. The cost for the fall semester was $23,400 and the estimated cost for the spring was $18,600 totaling a cost of $42,000 for the engineering services for this project.
Activity Date:
29 November 2021
Optimal Design Selection
After completing the analysis of the existing conditions on ArcMAP’s ArcGIS Software, the team successfully modeled the dam network on HEC-HMS. This software differs from ArcGIS because it allows the team to model the reservoirs and sub-basins response to rain events. The program was ready to simulate rain events once the area elevations and spillway characteristics were defined.
Activity Date:
16 November 2021
Optimal Design Selection
The team compiled the realistic and design constraints and developed three alternative designs to approach the project. The alternative designs were determined to be increasing the height of the dams, armoring the dams, and widening the spillway of the dams. According to the team's decision matrix, which was a preliminary ranking of the designs to address the constraints, the team agreed that the optimal design solution would be increasing the height of the dam. This design was determined to address the constraints the best, however, the team may need to take multiple approaches to rectifying the dams. Each member has unique dam characteristics and upstream flow conditions, so each member may employ multiple techniques, such as increasing the height and armoring. The team will individually adapt their design as the analysis continues.
Activity Date:
29 October 2021
ArcGIS Computational Analysis
With advisory and direction from Dr. Horst, the team was able to connect what they learned using StreamStats to the new program ArcGIS. The team utilized the software to find a more precise average watershed slope and longest hydraulic length for each sub-basin within the overall watershed. With persistent effort, the team overcame the unfamiliar syntax of the software and was able to produce precise results. The team will later utilize these results to perform their design analysis.
Activity Date:
17 October 2021
Watershed Analysis
The team has welcomed an industry advisor to the project. Sarah Hatala, from the Dam Safety sector of the Department of Environmental Protection, has been a vital component behind the scenes. She has helped us obtain the preexisting data of the dams, and has led us to other resources available, further driving our project.
The team has progressed into the analysis phase of the project. After data acquisition, the team decided to start the analysis by using StreamStats and WebSoilSurvey software. Overall, we were able to calculate the approximate soil types, watershed areas, curve numbers, and lag times. The team plans to use ArcGIS to more precisely read the watershed slopes to assess the accuracy of the calculations.
Activity Date:
26 September 2021
Data Acquisition at DEP
The team traveled to the Department of Dam Safety located in Trenton NJ to review the available data on the four dams that are being redesigned. The most critical information acquired from the meeting were blueprints and the HEC-1 input data which will allow the team to have a better understanding of the pre-existing geometry of the dams as well as rainfall data.
Activity Date:
16 September 2021
