Reservoirs are bodies of stored fresh water that typically form behind dams. They are a critical water source, supplying farms with irrigation and providing potable water to people and homes. Increasingly, they are also an important component of outdoor, water-based recreation.
As rivers flow, they naturally carry along sediment (clay, silt, sand, and gravel). When rivers are dammed, sediments are deposited in the reservoirs that form behind dams. Sand and gravel deposit at the upstream end of reservoirs and form deltas that also extend upstream beyond the full reservoir pool. Clay and silt deposit farther downstream along the reservoir bottom and all the way to the dam. Over time, these sediment deposits build-up to the point where they significantly reduce a reservoir’s storage capacity and may prevent the proper function of dam outlets and reservoir water intakes. Without intervention, reservoirs eventually become filled with deposits, which means water is no longer being stored for future use.
The Bureau of Reclamation (Reclamation) is the nation’s largest wholesale water supplier. They operate over 330 reservoirs that store 140 million acre-feet of water. For reference, an acre-foot is 325, 851 gallons - which is enough to supply a family of four for one year.
Reclamation, in collaboration with the U.S. Army Corps of Engineers (USACE), is sponsoring this three-phase Guardians of the Reservoir Challenge. The goal of this challenge is to develop and demonstrate new processes and technologies that will collect and transport sediment from reservoirs at a rate that sustains their current capacity. Reclamation’s primary interest is in technology that will move sediment downstream at the average annual rate at which it would otherwise accumulate, but approaches that can help in regaining lost reservoir capacity are of interest if they can do so in addition to meeting environmental and other performance criteria.
The authors of the most compelling submissions to this Guardians of the Reservoir Challenge will have the opportunity to develop and demonstrate their technologies at increasing scales for the Challenge sponsors. In addition to prize money, winners may receive review comments and/or observations from their technology demonstrations and may have additional opportunities to work with Reclamation, USACE, or their partners to further develop their approaches.
Submissions must be received by October 20, 2020
As many as 5 of the top submissions will advance to Phase 2. Winners each receive $75,000 (total of $375,000 awarded)
Phase 1 winners have approximately 15 months to work according to their proposed project plans, develop their proposed approaches, perform a laboratory-scale demonstration, and submit a report
As many as 3 of the top-performing approaches will advance to Phase 3. Winners each receive $25,000 (total of $75,000 awarded)
Phase 2 winners have approximately 9 weeks to prepare for a large scale demonstration (scale, location, and other demonstration specifics to be mutually agreed upon), where they will set up and run their scaled-up demonstration for Reclamation, USACE, and their partners
A final event will occur at the end of Phase 3. Teams participating in Phase 3 will present an overview of their approach and results to Reclamation, USACE, and possibly affiliated commercial partners
This Guardians of the Reservoir Challenge is part of a larger sustainability effort to maintain our nation’s reservoirs. These reservoirs and dams are all part of an important, but aging infrastructure. In addition to finding new ways of sustaining reservoir capacity, raising awareness about this problem is itself another objective of the challenge. It is hoped that developing new sediment removal strategies will jumpstart interest and activity in this area both within Reclamation, USACE, and within the larger water resource management community. Having a wide range of viable solutions will create interest among industrial partners to further develop and commercialize solutions. Additionally, new testing capabilities and methodologies will need to be developed to support those different solutions.
An earlier ideation challenge sponsored by Reclamation and USACE on this same topic provided many interesting ideas. This current challenge extends the effort of the previous one by offering development support and field testing opportunities to the most compelling ideas. It is open to everyone. Whether you are new to this topic, you missed the last challenge, or you have a new twist on an idea you submitted previously, this is a great opportunity. In the spirit of helping to set the community up for success, Reclamation is sharing some general thoughts to consider when putting together your ideas:
Technical maturity - Many of the earlier ideas would have required significant time and effort to prove the concept, let alone reduce it to practice. Whatever you propose, it must be something that can be successfully developed and demonstrated within the 15-month Phase 2 development window.
Practicality and scalability - Although many of the previous ideas were intriguing, it was clear that it would be impractical to implement them without additional resources at anything larger than laboratory scale - whether due to cost, time, or energy efficiencies, or robustness.
Expense - Even for ideas that are feasible and demonstrable, the cost to implement them ideally would be less than the cost of current methods or at least comparable.
Novelty - Many of the previously submitted (and non-selected) ideas were approaches already in use, with little or no improvement in capability. This challenge is looking for new ways of thinking about the problem. If you are using existing technologies, your approach should have some innovative element that provides a significant advantage in capability or reduces costs, maintenance, or downtime over the current version.
This Guardians of the Reservoir challenge seeks to do more than just identify and award good ideas. This challenge will identify the most promising of the submitted ideas, help to develop them, and hopefully enable full-scale demonstrations of them. The long-term objective is to connect promising technologies with industrial partners for further development and eventual commercialization. Successful commercial development of new sediment removal technologies will provide our nation with a suite of innovative and proven solutions to manage our reservoirs’ long term sedimentation problems for future generations.
Current approaches to managing reservoir sediment are variations of dredging, flushing, and sluicing. Dredging is essentially underwater excavation, in which sediment is collected and removed from the bottom of the reservoir. In mechanical dredging, buckets or clamshells dig and bring up sediment from the bottom. In hydraulic dredging, the sediment that is dug from the bottom is mixed with water to form a slurry that is then transported away. Dredging is expensive because of the large amounts of manpower, energy consumption, and equipment maintenance required. In the case of hydraulic dredging, the slurries of sand and gravel can be extremely abrasive. This means that the transport process is subject to regular downtimes for repair and preventative maintenance. Downtime for these types of operations is expensive since both personnel and equipment are idle during these periods.
Flushing is the process by which water in the reservoir is used to help transport previously deposited sediment downstream from the reservoir. This can be done in several different ways. In pressure flushing, the reservoir level is not lowered down while water is released through dam outlets. The pressure of the water overhead scours sediment in the vicinity of those outlets. In drawdown flushing, the water level is lowered down. This creates high velocities as the water moves across the reservoir, allowing the water to transport sediments through the dam's low-level outlets. While this method does not have all of the equipment issues and costs associated with dredging, flushing uses large amounts of precious freshwater that could otherwise be used to supply cities and towns, or for irrigation. This technique is not equally effective in all reservoirs, and flushing can have detrimental effects to ecosystems downstream.
Sluicing prevents inflowing sediments to the reservoir from depositing by lowering the reservoir water level prior to high flows that contribute large amounts of sediment. The inflowing sediments are transported through the reservoir with reduced deposition. Sluicing also reduces the amount of water stored within the reservoir.
The Resources tab contains additional information about reservoirs and sediment management. Some of the drawbacks to current methods for removing sediment from reservoirs include:
Expense - Dredging approaches can cost more than $20/yd3, in some cases significantly more
Durability and reliability - Sand and gravel can be very abrasive, which causes equipment failure and subsequent downtime
Versatility - Reservoirs are not uniform in size or shape. Some reservoirs have unique characteristics that make some Guardians of the Reservoir approaches less effective. In particular, many currently-used dredging methods do not work well in deeper reservoirs (>50 ft deep)
Water loss - Reservoir flushing or sluicing uses water to either clear sediment from in and around dam outlets or to wholesale push sediment through low-level outlets. Either flushing or sluicing sacrifices valuable water reserves.
Ideal solutions to this challenge will be applicable to a wide range of sediment types and reservoir geometries. But solutions that specifically address a targeted issue, such as just sediment collection or transport, deeper reservoirs, more cohesive sediments, or very abrasive sediments are also of great interest. Regardless of whether the solution is broader or more narrowly focussed, successful solutions must be practical, scalable, and cost-effective. Reclamation and the USACE are interested in innovative approaches that may have additional capabilities over existing sediment removal solutions. For example, currently used methods do not perform well in deeper reservoirs (deeper than 50ft), and having new options for managing capacity at those deeper reservoirs would be of great interest. Additionally, many of the current approaches do not perform well in freezing weather conditions when ice is prevalent on the reservoir surface. This limits the window for sediment management work. Reclamation and USACE would also be interested in something that either operates continuously or can be permanently installed at a given reservoir. Finally, many of the currently used approaches are very energy-intensive and present large carbon footprints. New, more efficient, and more sustainable approaches are needed.
In addition to the desired performance specifications discussed above, there are other solution constraints. Reclamation and USACE reservoirs are an important part of outdoor recreation activities in the US. These outdoor recreation activities contribute billions of dollars to regional economies. Outdoor recreation opportunities include water-based activities such as boating, fishing, and swimming as well as camping, hiking, and photography. Any successful sediment removal solution must be able to coexist with these recreational activities, without limiting access to large areas of the reservoir or endangering visitors.
Environmental safety is also important. Proposed approaches should not release harmful materials into the water or the air and should not endanger wildlife in the vicinity where sediment management operations are in progress. Successful solutions will introduce the smallest possible environmental footprint - meaning that noise levels, water temperature fluctuations, equipment emissions, etc. are either minimal or are accompanied by some impact mitigation measures.
Everyone is invited to participate in Phase 1. The deadline to submit your responses is October 20, 2020. Reclamation and USACE are interested in novel approaches to collect and/or transport reservoir sediment that are more efficient, use less energy and/or less manpower, are more durable, and operate in a wider range of reservoirs than currently used methods. Regardless of the technical maturity of your approach, it must be something that can be successfully developed and demonstrated within the 15-month Phase 2 development window. In addition to providing a strong scientific rationale and any preliminary data for your proposed approach, submissions must also include a realistic project plan that clearly outlines the timeline and path that will enable your approach to be ready for the Phase 3 demonstration event.
Submissions that have passed a pre-screening step - which removes non-responsive and/or incomplete submissions - are reviewed by the Evaluation Panel. They will select up to 5 of the most compelling submissions as Phase 1 winners. Winners will be selected based on how submissions score against the evaluation criteria, see below. Each winner will receive $75,000 award money to support their development efforts.
The Phase 2 development period is approximately 15 months long, with a mid-point check-in during August 2021. Phase 1 winners will each receive $50,000 of their award money at the start of the development period and will be assigned a technical point of contact (POC) from Reclamation. It is anticipated that teams will be in regular contact with their POCs throughout the development period: advising the POC of changes to the project plan or of any unforeseen roadblocks, requesting time with an SME, asking for advice, informing the POC of important breakthroughs, etc. In addition to development funds won from Phase 1, Phase 2 teams will also have up to 40 hours of access to SMEs. The experts will be drawn from Reclamation and USACE, depending on the specific expertise required by a team. During the mid-point check-in, each team will review with Reclamation and USACE their progress relative to the project plan submitted in Phase 1. Additionally, they will present a video showing a lab-scale demonstration of the proposed technology, or progress towards such a demonstration. After successful completion of the check-in, teams will each receive the remaining $25,000 of the award money to aid in the continued development of their approach.
During this check-in, each team and Reclamation will mutually agree upon what a large scale demonstration at Phase 3 will look like. Depending on the specific technology being developed and the progress being made, the definition for large scale demonstrations may vary. For example, for a sediment collection approach, a Phase 3 demonstration might be collecting 500 cubic yards of silt and sand (size gradation will be specified) from water depths ranging from 20 to 50 feet and doing this for 6 hours per day over a time period of 3 days. The team would have to explain how their approach would work in deeper depth.
For a sediment transport approach, teams could be asked to demonstrate their approach by transporting sand or gravel (size gradation will be specified) at a rate of 20 cubic yards per hour, a horizontal distance of at least 500 feet, over a hill rising and falling at least 25ft and doing this for 6 hours per day over a time period of 3 days. Abrasion could be tested at an accelerated rate.
At the end of the Phase 2 period, each team will submit a report that contains a summary of the development efforts, supporting data, and detailed descriptions of improvements and changes made since the mid-point check-in, including any additional videos. The Evaluation Panel will review the reports and evaluate the teams for performance relative to both their project plan and the challenge’s stated performance criteria. Up to 3 of the top-performing teams will advance to Phase 3 and will each receive an additional $25,000 to support travel and associated costs with participation in the Phase 3 large scale demonstration.
Soon after the Phase 2 winners announcement, the specific locations and dates of the large scale demonstrations will be shared with each winning team. These demonstrations will occur during the Phase 3 demonstration period, which is approximately 9 weeks long. During this time, teams may continue to refine their technologies until the specific demonstration itself, but they will be required to provide a written report that documents any improvements made since the submission of the Phase 2 report. The Evaluation panel, and possibly additional personnel from Reclamation and USACE, will attend each demonstration.
At the conclusion of the demonstration period, a final event will be held. Each team will present an overview of their work over the course of the challenge. This event will provide an opportunity for teams to interact with one another, with various personnel from Reclamation and USACE, and with potential commercial partners invited to the event.
At the end of the Phase 3 networking event, the Evaluation Panel will select and announce the final winner of the Guardians of the Reservoir Challenge. The selection will be made based on the winning technology’s performance relative to the challenge’s stated performance criteria, and may also be swayed by input from experts attending the event relating to issues such as: long-term costs, durability, prospects for commercialization, etc. The final winner will receive a $100,000 cash award.
Performance targets for Phase 3 demonstration
Although it is difficult to set targets in advance of receiving proposals from the community, Reclamation and USACE hope to facilitate the development of promising technologies to levels well beyond laboratory-scale. The performance targets described below are intended to help the community understand Reclamation’s and USACE’s goals for this challenge. Should a team be unable to meet the target, they may yet be considered successful by the Evaluation Panel - depending on individual situations and contributing factors. Actual performance targets will be set individually with each team during their Phase 2 check-ins.
For sediment collection, teams could be asked to demonstrate their approach by collecting 500 cubic yards of silt and sand (size gradation will be specified) from water depths ranging from 20 to 50 feet and doing this for 6 hours per day over a time period of 3 days. The team would have to explain how their approach would work in deeper depth.
For sediment transport, teams could be asked to demonstrate their approach by transporting sand or gravel (size gradation will be specified) at a rate of 20 cubic yards per hour, a horizontal distance of at least 500 feet, over a hill rising and falling at least 25ft and doing this for 6 hours per day over a time period of 3 days. Abrasion could be tested at an accelerated rate.
Phase 1 open to submissions July 14, 2020
Phase 1 submission deadline October 20, 2020 @ 5pm ET
Phase 1 judging and evaluation October 20 - December 1, 2020
Phase 1 winners announced December 8, 2020
Phase 2 development period December 8, 2020 - February 15, 2022
Phase 2 mid-point check in August 10, 2021
Phase 2 reports due February 8, 2022
Phase 2 judging and evaluation February 8 - March 22, 2022
Phase 2 winners announced March 29, 2022
Phase 3 demonstration period April 5 - June 10, 2022
Phase 3 final event June 21-22, 2022
Phase 3 winner announced June 22, 2022
How do I win?
To be evaluated by the evaluation panel, the proposed solutions will minimally:
Present an approach for collecting and/or transporting sediment from reservoirs
Provide complete and thoughtful responses to the submission form prompts
Submissions that have passed the pre-screening process will be evaluated by the evaluation panel, using the Judging Criteria listed below.
Phase 1 Judging Criteria
Is the submission complete and responsive? Is the writing clear, concise, and compelling? Are the ideas and information presented thoughtfully and in an easy follow manner?
Soundness of Proposed Approach
Is the proposed idea technically sound? Is it likely to be practical and scalable when fully developed? Are there any issues with efficiency, durability, or operational constraints? How is the proposed approach an improvement over current methods? Is it environmentally friendly and sustainable?
Potential for the proposed approach to be developed, demonstrated and validated
What is the technical maturity of the proposed approach? Is the proposed approach likely to be validated with a successful lab demonstration within the timeframe of this challenge?
Are the proposed costs competitive with or better than those associated with current methods? Are there additional capabilities offered by the proposed approach that would affect the calculation of the cost proposition? Are the assumptions used for the cost estimation realistic?
If the proposed approach were successfully demonstrated in the lab and/or at the Phase 3 demonstration event, what is the likelihood that an industrial partner would fund it for further development and eventual commercialization?
Is the submitted project plan realistic, clear, and indicative of a good understanding of the major hurdles that must be overcome for successful prototype development. Does the project plan clearly outline the activities and milestones that must occur in order to successfully demonstrate the proposed approach at the correct scale by the Phase 3 demonstration? Are all environmental impacts identified and addressed with mitigation measures?
Does the team contain the necessary skills and expertise required to execute the project plan. Does the team have adequate access to resources and other experts, as needed?
How novel and innovative is the proposed approach? Does it represent a completely new approach? Does it use existing technology in a new or unusual way (that offers unexpected benefits or cost savings)? Does this represent an incremental improvement or a significant one?
Phase 1 Submission Form
Team Information: For each team member: please list their names, their roles/expertise, and their email addresses. Please note who is the team leader/primary point of contact.
Please select the option that best describes your proposed solution:
Complete solution for Guardians of the Reservoir
Proposal Overview: Please provide an overview of your proposed Guardians of the Reservoir approach:
What is it?
How is it an improvement over current methods?
Why do you believe it can be developed and demonstrated within the timeframe of this challenge?
Technical Details: Please discuss in detail the scientific rationale for your proposed approach. We are particularly interested in your thoughts about practicality, scalability, and efficiency:
What do you see as a realistic removal rate when your approach is fully scaled?
What are the likely points where equipment might fail, or problems might occur? What are possible mitigation strategies?
How easy will this approach be to deploy and how robust will it be to variability in field conditions?
Cost Using this approach, what do you estimate the Guardians of the Reservoir cost per yd3 to be when it is fully scaled? What is the rationale for this cost and what assumptions are you making? How does this cost compare with the current cost range for sediment removal? Does your proposed approach offer advantages that are not captured by a cost number? If so, what are they?
Technical Maturity: What do you estimate the TRL for your proposed approach to be currently? (Select from list)
TRL 1 – Basic principles observed
TRL 2 – Technology concept formulated
TRL 3 – Experimental proof of concept
TRL 4 – Technology validated in lab
TRL 5 – Technology validated in relevant environment (industrially relevant environment in the case of key enabling technologies)
TRL 6 – Technology demonstrated in relevant environment (industrially relevant environment in the case of key enabling technologies)
TRL 7 – System prototype demonstration in operational environment
TRL 8 – System complete and qualified
TRL 9 – Actual system proven in operational environment
To what TRL do you realistically think you can advance your approach during the development period? (Select from list, same options as Q6)
Project Plan: Please provide a realistic project plan for how you would develop your proposed approach into something that can be demonstrated at lab-scale and then at a larger scale at the Phase 3 demonstration event. Your project plan should include the following milestones:
Project start: Dec 2020
Lab-scale demonstration and mid-point check in: August 2021
Final report due: Feb 2022
Demonstration event: June 2022Remember, if you are selected as a Phase 1 winner, you will be expected to execute against this project plan.
Additionally, please discuss the resources and expertise that you will need to successfully develop your proposed approach. If there are resources and/or expertise needed that are currently not available to your team, how do you plan to address these gaps?
What do you anticipate will be the biggest hurdle in successfully developing and demonstrating your technology? What are your current thoughts about how to tackle it?
Commercial Potential: What do you think is the commercial potential of your proposed approach? Why would an industrial partner want to help you commercialize your technology?
Novelty/Innovation: How would you characterize your approach with regards to innovation? Is this a completely new way of approaching the problem? Does this take known technologies and use them in a novel way? Does this approach yield significant improvements (as opposed to incremental improvements) over existing methods?
Phase 3 demonstration: If your proposed approach is selected and you advance through to Phase 3, how would you envision demonstrating the validity of your solution? At what scale would your approach likely be demonstrated. What type of facility would you need for your demonstration and what site-specific requirements would you have? How would you document the results of this demonstration?
Supporting Files: Please upload any supporting files, such as design files, a bibliography or citation list, etc.
Note that your submission should be complete and judgeable without the additional content in any supporting files.
Phase 2 Judging Criteria
Does it offer new capabilities that are currently not available?
If widely deployed, does it offer the potential to maintain or even improve on current reservoir capacities?
Breadth of applicability
Can it be used in all, many, or just some reservoir settings?
Is it likely to lower the overall cost/yd3 for sediment removal?
Safety and Environmental Issues
Is it safe and environmentally friendly? For example:
How does it impact the downstream environment?
Does it have a smaller carbon footprint than current methods?
Can it be safely used in the presence of recreational activities?
Improved efficiency by reduced downtown, reduced manpower, reduced maintenance, reduced energy requirements, etc
Phase 3 Judging Criteria
Overall removal rates
Transport rates (and associated wear rates on pipelines)
Anticipated frequency and duration of downtime (preventative maintenance and repairs)
What is the likelihood that the approach will have increased longevity compared with existing methods?
Will the approach lead to increased productivity (overall removal rates per amount of user effort)?
Does the approach have a reduced environmental impact, compared with other methods?
Is the approach likely to save money?
Will the approach save time?
Is the approach offering other advantages or capabilities that are currently not available?
Is it able to pass an accelerated abrasion test? Rules
The following restrictions apply to the Challenge:(1) Federal employees acting within the scope of their employment are not eligible to participate; (2) Federal employees acting outside the scope of their employment should consult their ethics advisor before participating in the Challenge; (3) All employees of the Government, [contractor(s)], Challenge sponsors, and other individual or entity associated with the development or administration of the Challenge, as well as their family members (i.e., spouse, children, parents, siblings, other dependents) and persons living in the same household whether or not related, are not eligible to participate; (4) Contractors receiving Government funding for the same or similar projects, along with their employees, are not eligible to participate in the Challenge.
Submissions must be made in English. All challenge-related communication will be in English.
To be eligible to compete, you must comply with all the terms of the challenge as defined in the Challenge-Specific Agreement, which will be made available upon registration.
Registration and Submissions:
Submissions must be made online (only), via upload to the HeroX.com website, on or before the submission deadline. All uploads must be in PDF format. No late submissions will be accepted.
Intellectual Property Rights:
Title in all intellectual property rights, if any, developed by Innovator as part of the Submission will remain with the Innovator. Please read the full details in the Challenge Specific Agreement here (updated 8/25/2020).
By participating in the challenge, each competitor agrees to submit only their original idea. Any indication of "copying" amongst competitors is grounds for disqualification.
All applications will go through a process of due diligence; any application found to be misrepresentative, plagiarized, or sharing an idea that is not their own will be automatically disqualified.
All ineligible applicants will be automatically removed from the competition with no recourse or reimbursement.
No purchase or payment of any kind is necessary to enter or win the competition.
The Bureau of Reclamation has selected five projects to each receive $75,000 through phase one of the Guardians of the Reservoir Challenge. The winning submissions are:
Wing Marine Team composed of Doug Thompson, John Crowson, Mel Friedman, Peter Crossland, Bryan Longhurst, James Coats, and Joel Friedman, Texas, A Cure for Ailing Reservoirs.
Nicholas LaBry and Kenneth LaBry of Prometheus Innovations, LLC., and Bartolomeo Mongiardino of Hydro Maintenance Service, Louisiana, The 3 D DREDGER™: Complete Sediment Management.
Dr. Peter Murdoch and Dr. John Newport, Pennsylvania, Air Bubble Suction Pipe with Water Recirculation.
Baha Abulnaga, Washington, High Volume Deep Dredging for Low Water De-silting.
Dr. Michael Detering, Laura Backes, and Joana Kueppers, Germany, Sediment Continuity and Restoration.
Thank you to everyone who participated in Phase 1 of the Guardians of the Reservoir Challenge. We received over 90 submissions and the judging panel was impressed with the quality and caliber of the submitted proposals.
The Phase 2 development period is approximately 15 months long, with a mid-point check-in during August 2021. In addition to development funds won from Phase 1, Phase 2 teams will also have up to 40 hours of access to subject matter experts. At the end of the Phase 2 period, each team will submit a report and up to 3 of the top-performing teams will advance to Phase 3 and will each receive an additional $25,000 to support travel and associated costs with participation in the Phase 3 large scale demonstration.
Congratulations once again to our Phase 1 Winners!
It's not too late! There is still one more day to submit your innovative ideas to the Guardians of the Reservoir Challenge. As a final reminder, you must finalize your submission prior to the deadline, which is tomorrow at 5pm ET.
There is 1 week left until we need your submissions for the Guardians of the Reservoir Challenge.
To be considered eligible for the judging stage, you must complete and finalize your submission before the deadline (October 20th at 5pm ET) and meet the requirements outlined in the Guidelines section.
In case you need assistance, you can view a How-To video on completing your submission here.
This is your official 2-week reminder for the Guardians of the Reservoir Challenge! Submissions are due on October 20th at 5 pm ET.
We have been receiving a few questions on the characteristics of reservoirs that your solution could work on. The Bureau of Reclamation and the U.S. Army Corps of Engineers (USACE) operates hundreds of reservoirs across the United States. While each reservoir is different, they typically share some common characteristics:
Typical lengths range from 1 to 30 miles (2 to 50 km) upstream of the dam with sedimentation along the entire length.
Annual reservoir sedimentation inflow rates typically range from tens of acre-feet per year to thousands of acre-feet per year. These sediment inflow rates are equivalent to tens of thousands of cubic yards per year to millions of cubic yards per year (tens of thousands of cubic meters per year to millions of cubic meters per year).
Sedimentation includes the whole range of grain sizes, i.e. clay, silt, sand, gravel, cobble. Sand, gravel, and cobble tend to deposit as shallow deltas at the upstream ends of the reservoir. Clay and silt tend to deposit farther downstream along the reservoir bottom.
Sedimentation typically includes submerged wood of various sizes (twigs to logs). However, woody debris is not a focus of this competition.
Presently, nearly all inflowing sediments are trapped within water storage reservoirs and little, if any, sediments are released downstream. Existing dams were not designed to pass sediment downstream. Long-term sustainability of reservoir storage can only be achieved by transporting inflowing sediments downstream or removing sediments from the river system.
With new capabilities, reservoir sediments possibly could be passed downstream from a dam, in various amounts, during all months of the year. Passing sediments downstream at concentrations that match the reservoir inflow would be desirable, but this is not a requirement of this competition.
Limits on the downstream passage of reservoir sediment are not part of this competition. In practice, any such limits would be related to the capacity of the downstream river channel to transport sediment.
Recovering past reservoir storage capacity loss would be great, but the sedimentation volume is typically too large to be economically feasible, would exceed the downstream sediment transport capacity, and is too large to be removed from the river system.
Reservoir sedimentation is typically at water depths that range from 1 to 200 feet (0.3 to 60 m).
Typical depths from the reservoir water surface to the lowest dam outlet are 30 to 150 feet (10 to 50 m), but these outlets were not designed to pass coarse sediment or wood.
Reservoir water levels fluctuate both seasonally and year to year. Seasonal fluctuations may range from 2 to 20 feet (0.6 to 6 m). Year to year fluctuations can range from 5 to 50 feet (2 to 15 m).
The height of the dam above the normal reservoir water level typically ranges from 20 to 100 feet (6 to 30 m). Spillways are typically 10 to 80 feet (3 to 25 m) above the reservoir water surface.
The drop in elevation from the top of the dam down to the downstream river channel typically ranges from 50 to 300 feet (15 to 90 m).
Reservoirs in northern USA latitudes typically have ice on the reservoir surface during winter while reservoirs in southern latitudes typically do not have ice. In cold regions, ice may be thicker than 1 foot (0.3 m).
Certain life stages of fish and wildlife could require curtailment of sediment removal activities at specific locations within some reservoirs, but this is highly site-specific and not part of this competition. In general, solutions need to avoid widespread disruptions to fish, wildlife, and recreation throughout the reservoir.
With low noise levels and unobtrusive lights, reservoir sediment removal activities could occur 24-hours per day, seven days per week.
We have presented four case studies of specific reservoirs to provide a more robust image of the diversity and variability of the reservoirs managed by BOR and USACE (view the case studies here). We encourage you not to get caught up in the details of these specific case studies. If you propose a solution that works for certain characteristics, we can likely find a reservoir with those characteristics where sediment removal solutions are needed.
As a reminder, if you have any questions regarding the competition, you can post it in the forum here or email us at firstname.lastname@example.org
We look forward to receiving your innovative ideas!
We are about a month away from our submission deadline for the Guardians of the Reservoir Challenge!
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View a How-To video on completing your submission here.
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