GCDAMP- Questions and Answers Page
THIS PAGE IS CURRENTLY UNDER CONSTRUCTION
Research Questions and Information Needs Identified in the 2013-14 Glen Canyon Dam Adaptive Management Program Biennial Budget and Work Plan
- Revision Date_140212
| Num | Project, Elements, and Sub-elements | Project/Element summary (from the 2012-13 BWP) | Research Questions, Uncertainties, & Information Needs identified in the 2012-13 BWP | Relevant Research Questions & Information Needs identified from: | Project timeline: When will data obtained through this project be able to answer the relevent science questions? | Project funding (FY) | Reporting links | NOTES |
|---|---|---|---|---|---|---|---|---|
| 000 | Project A. Sandbars and Sediment Storage Dynamics: Long-term Monitoring and Research at the Site, Reach, and Ecosystem Scales | Project will evaluate the geomorphology of fine sediment deposits in and near the Colorado River. Supports the direct measurements of the volume of fine sediment, especially sand, that is stored on the bed of the Colorado River, in its eddies, or at higher elevation along the river's banks. Supports the direct measurement of the volume of fine sediment, especially sand, that is stored on the bed of the Colorado River, in its eddies, or at higher elevation along the river’s banks for the HFE protocol. Monitoring will include daily and annual observations of long-term sandbar monitoring sites by remote camera and conventional topographic survey, respectively. Also includes the analysis of system-wide airborne remote-sensing data to monitor a much larger set of sandbars every four years to assess sandbar size and abundance | "Project will address the broad questions of:
(1) Will multiple high flows conducted over a period of years result in net increases in sandbar area and volume?; (2) With the available sand supply (i.e. tributary inputs), is the approach of using repeated floods to build sandbars sustainable?;and, (3) Will multiple high flows conducted over a period of 10 years result in net increases in campable area along the Colorado River?" |
"How can erosion of sandbars after an HFE be minimized or offset? (IV: Dept. of Interior 2011a)
Do sandbars deposited by HFEs contribute to preservation of archaeological sites in the river corridor? (II: Mellis et al. 2007) Is sediment conservation more effective when an HFE is held in rapid response to sediment input from the Paria River? (IV: Dept. of Interior 2011a) What are the effects of ramping rates on sediment transport and sandbar stability? (USGS 2007b; SSQ RIN 4) What is the desired range of seasonal and annual flow dynamics associated with powerplant operations, BHBFs, and habitat maintenance flows, or other flows that meet GCDAMP goals and objectives? (USGS 2007b; RIN 7.4.1) What is the desired pattern of seasonal and annual flow dynamics associated with powerplant operations, BHBFs, HMFs, or other flows to meet GCDAMP Goals and Objectives? (USGS 2007b; RIN 7.4.2) What elements of ROD operations (upramp, downramp, maximum and minimum flow, modified low fluctuating flow (MLFF), habitat maintenance flow (HMF), and BHBF) are most/least critical to conserving new fine-sediment inputs, and stabilizing sediment deposits above the 25,000 cfs stage? (USGS 2007b; RIN 8.5.1) How do sandbar textures influence biological processes? (USGS 2007b; SIN 8.5.) What is the relationship between the fine-sediment budget and turbidity? (USGS 2007b; SIN 8.5.2) How can the ongoing fine sediment supply be managed to achieve sustainable habitats? (USGS 2007b; SIN 8.5.5)" |
AMWG | |||
| 000 | Meeting Minutes: | LINK | Minutes | 1997 | AMWG |
UNDER CONSTRUCTION:
- To be added: From Knowledge Assessment_"Assessing what we know and don't know_8-22-2011"- USGS
- The food web on which fish depend is very simple
- Availablitity of high-quality food resources limits fish populations- Black Flies and midges are the most important parts of the present food web.
- The mainstem Colorado River water temperature is typically well velow the termal optimum for native fishes, but recently has been warmer.
- Warming increases growth/ production of algae and invertebrates.
- Warming increases the growth rate of humpback chub.
- We don't understand the decline in RBT between 2001 and 2007.
- Rainbow and brown trout disproportionately prey on native fish.
WHAT WE DON'T KNOW--
- Will warmer mainstem temperatures alone allow for increased survival of humpback chub?
- Do trout have substantial population-level effects on humpback chub?
- What ages of HBC are most impacted, and by what mechanisms? Competition, predation...
Contents
RAFTING RELATED
- Do rafting groups get told not to cave-in sandbars?
SEDIMENT RELATED
- Sediment Retention:
- Q: How do intervening flows effect retention of sand bars? A
- Q: In order to retain sandbar life following an HFE, has riprap been considered as a possible action against erosion in the Grand Canyon?
A: The park system was created to conserve unimpaired the resources and values that the park was set aside to protect. Natural landscapes disturbed by natural phenomena will be allowed to recover naturally (where possible). Landscape and vegetation conditions altered by human activity may be manipulated where the park management plan provides for restoring the lands to a natural condition. This usually entails removing the man-made objects (like a fence, structure, or even a dam) to bring the area back to a natural state. If the use of man-made objects or non-native species proves worthy in restoring a landscape, it can be used to a limited degree, and as long as it is done on a temporary basis and does not impair the resources.
In addition, one needs to factor in wilderness management (which applies to the lands along the river). Because the beaches are within NPS proposed wilderness recommendation, They are required to manage the area as Wilderness; including the values of naturalness, primitive and unconfined recreation, solitude, and special values. No action can be taken that would diminish the area's wilderness eligibility until after Congress and the President have taken action. This aspect takes us back to the "as natural as possible" discussion and would be a prohibitive factor for such actions as rip-wrapping and other such man-made structures.
>>Also consider-- the cost of doing such work in the Grand Canyon may even exceed that of sediment augmentation. ---Riprap, HFE, Sandbars erosion
FISH RELATED
- How often do native fish get handled?
DAM- General Overview
- What resources have been improved because of the dam?
- Was there more or less vegetation along the river after GC Dam was built?
Monitoring
- How far back does the readings of the gauges go? Pre-dam?
Flow Regimes
- Do steady flows produce more trout?
- Do steady flows lead to increases in vegetation encroachment?
