Replies to questions regarding 2018 Flushing Flows RFP
Question 1: In the purpose of the RFP, the Suite of Conceptual Flows Table is referenced. In this table, the function, objective, and flow regime are outlined for Flushing Flows, Channel Maintenance Flows, and Riparian Maintenance Flows. Can you confirm that this RFP is intended to address the Flushing Flows or is the intent of the RFP to also address Channel Maintenance Flows and Riparian Maintenance Flows?
Answer 1: This RFP is intended to only address Flushing Flows. The SG is considering a separate RFP to address Channel Maintenance Flows, but has not reached a consensus decision. A study to determine Riparian Maintenance Flows is unlikely to be addressed by the SG.
Question 2: Based on the snow pack and flows in 2018, it is a real possibility that should another low snow pack year occur in 2019 the flushing flow of 2,000 cfs may not occur in parts of the study area defined in the RFP. If this is the case, it will be unlikely that any field or modeling studies could fully complete objective #1 in the RFP. Should this occur in 2019, it would likely be known in March or April prior to runoff based on the available snow pack data. What options would be available to the project team? Is it possible to delay the study until 2020 hoping for better runoff or could the SG work with water managers in the Upper Colorado River Basin to create a short artificial release of at least 2,000 cfs?
Answer 2: The SG recognizes that a flow of 2,000 cfs may not occur in 2019. The SG's goal is to finalize a management plan by summer of 2020; however, the SG has not determined how the group will move forward in the event of insufficient data. It would be helpful for proposals to identify proposed study components that would require high flow events (2,000 cfs or higher) and if there are components that may be completed at flows less than 2000 cfs. Ideally, proposals will include a backup plan if 2,000 cfs flows do not occur in 2019 or propose other approaches the SG could consider to validate the flushing flow estimate. It is unlikely that the SG will be able to influence flows to create a short release of 2,000 cfs for this purpose.
Question 3: Currently, the 5 riffles suggested in the study area section of the RFP are not located at any of the three USGS gages in the study area. Would it be an effective use of funds from this RFP to collect hydraulic data such as velocity, depth, cross sectional area, or discharge at these 5 riffles? Would it be an effective use of funds from this RFP to establish temporary gages at the riffles to determine the exact flows at the riffles? In other words, would it be recommended to corroborate any sediment transport data collection to the existing gages because they will be operated in perpetuity or to also collect hydraulic data using temporary gages or discharge measurements at the specific riffles of interest?
Answer 3: Some hydraulic data has already been collected at the 5 cross-sections (See the Beeby and Bledsoe report) and could potentially be made available. The SG has not decided whether to continue monitoring macro-invertebrates at those sites on a long term basis. It may be helpful to have some hydrologic (flow) data collected in those locations, but the existing gage data should provide a reasonable indication of streamflow.
Question 4: Is there a specific proposal format or length recommended as it didn't seem any were suggested in the RFP?
Answer 4: There is not a specific proposal format or length.
Question 5: Will the 2D hydrodynamic models and associated data, particularly grain size estimates, created by Miller Ecological Consultants in their 2011 report be available for use by the successful proposal team?
Answer 5: Data and analysis collected as part of the Miller 2011 study can be provided on request via CD.
Question 6: Is there a general funding target ($10,000? $100,000)? It would help us in our budget planning.
Answer 6: At this time the SG has not determined the amount of funding for the Flushing Flow study. Previous studies conducted by the group have ranged between approximately $5,000 and $60,000. The SG may consider a larger scale project, but the SG has limited funds and is looking for efficient proposals to complete this work.
Question 7: Do you think there will be an adequate window where the river is free of ice, where field work can be conducted before snowmelt runoff?
Answer 7: The possibility of a window depends on how cold winter is, how much snow pack accumulates, and how quickly things warm up in the spring. Recent winters have been relatively mild (especially 2018) which allowed relatively ice-free access to the reach all winter; however this is not typical. Members of this group have observed in some years, a short window where the ice is melted off the river in March, but snowmelt runoff has not begun. However, in years where the temperature increases very rapidly in the spring, sometimes as soon as the ice is melted, flows can ramp up quickly because low elevation snowmelt has begun.
Question 8: Would we be able to use a motor on a cataraft to collect survey data, as they did in the Miller, 2011 study?
Answer 8: Above State Bridge, the BLM Kremmling Field Office has closed all BLM-managed open (i.e. non ice-covered) public waters (e.g., rivers, lakes, ponds, and reservoirs) to motorized use unless use is consistent with the area’s management objectives, and is approved by the BLM’s Authorized Officer. If use of a motorized craft is advisable for cost considerations, or necessary for safety and/or other reasons, the SG may be willing to request approval by the BLM for purposes of this study. Below State Bridge, the BLM Colorado River Valley Field Office does not have any such closure or requirements.
Question 9: Would we be able to install water level loggers along sections of the study area, to collect model calibration data?
Answer 9: No permits are needed for installing water level loggers in the river. The BLM would need to look at a proposal if there was potential surface disturbance for an anchoring system or access to the site. Please note that two different BLM field offices manage this section, see Answer 8.