Project 2105 License Group (2105LG) Meeting Summary

September 2, 2004


Call to order: Patti Kroen, Facilitator at 10:00 a.m.


Attendees:  See Attachment 1 for list of attendees that signed in.  Six community members made introductory remarks on behalf of the more than 150 Lake Almanor area residents and interested public in attendance.  The issues important to the community include study results that find negative impacts to Butt Valley Reservoir and impacts to the thermal regime within Lake Almanor resulting from installation of the curtain; negative economic impact to local community; consideration of the adverse consequences of constructing these curtains and completion of a sound analysis of alternatives.  The public was also concerned that no state Department of Fish and Game or State Water Resources Control Board representatives were present at the meeting.  Plumas County also provided a list of discussion topics to be covered during the meeting (see Attachment 2). A representative from Forest Community Research circulated a sign-up sheet for information regarding a planning effort to develop a basin plan for the community.  Attendees were provided an e-mail address ( for further information.


Collaborative Protocols/Disclosure Language:  The Facilitator reminded the 2105LG of an unresolved action item from the last meeting related to disclosure/draft language to be added to information and presentations posted and distributed.  The 2105LG discussed the importance of timely distribution of information relative to the relicensing and agreed that whoever generates the document/presentation will include ‘draft’ and/or ‘preliminary’ on items they determine as such prior to posting on the web site.  The 2105 Committee reminded participants that information regarding the collaborative process, including past meeting summaries and presentations could be found at


The 2105LG discussed the practice of electronic meeting noticing and added a representative from the local newspaper to the distribution list.  PG&E agreed to further discuss posting meeting notices in the local newspaper although it is not their practice to do so on any relicensings.  All meetings remain open to the public and anyone may be added to the e-mail distribution list by sending their address to the Facilitator at


The Facilitator reminded the 2105LG that she was hired by them to protect the collaborative process they had defined for themselves and as part of that job she felt it was necessary to revisit sections from the protocols that appear to have been breeched.  She indicated that several participants had approached her individually to discuss this issue and so she wanted to bring it to the attention of the full 2105LG for discussion.  She distributed copies of sections from the 2105LG collaborative meeting summary from November 2002 (Attachment 3) along with added protocol language from December 18, 2002 under Personal Conduct: (f) Negotiation: Participants who disagree with decisions, topics discussed or direction taken by the collaborative will not “try the proposal in the media” outside the collaborative process as a means of influencing decisions or discrediting collaborative participants.

After some discussion, the participants expressed little concern that the protocols had been violated and agreed to move forward under the existing protocols without amendment.


About 20 Questions:  As agreed at the last 2105LG meeting, USFS compiled a list of the questions asked during discussions on the Prattville modification under evaluation (see Attachment 4, Prattville Temperature Issues, August 25, 2004).  The 2105LG discussed several of the major issues and heard many comments and questions from the public.  The 2105LG agreed that PG&E would prepare answers for these questions for distribution prior to and discussion at the next 2105LG meeting. 


ACTION ITEM 6: PG&E will prepare answers for these questions for distribution prior to and discussion at the next 2105LG meeting.


ERC Update:  The Ecological Resources Committee (ERC) formed by the Rock Creek-Cresta settlement agreement have made no decision regarding the proposed Prattville modification and are still reviewing information and study data.  The 2105LG discussed the decision-making process within that group and how it differs from the 401 Certification process and decision to be made for 2105.  The 2105LG discussed how ‘reasonableness’ will be applied when considering overall watershed ecology and how a determination is made that enough studies have been completed and a decision can be made.


Members of the public expressed additional concerns during an informal public comment period. The comments are summarized as follows:

·        Potential for Maidu cultural sites to be disturbed by dredging activities

·        Temperature objective cannot be met in all years so the fish will die.  How is this a better situation than already exists in the system?

·        Interest in restoring Indian Creek as alternative cool water input

·        Mechanical cooling of the water should be evaluated

·        Consider changing the designation of the lower reach from cold water to warm water

·        Appears to be similar to the Middle Fork under unimpaired conditions

·        Potential to dredge behind reservoirs, creating deeper and colder pools to draw from

·        Ratepayers should not pay for this because it provides minimal benefit for huge economic and environmental costs.

·        Concern that the literature doesn’t support the 20 degree C target temperature

·        Consider alternative operation at Caribou powerhouses

·        Consider changing delivery timing for agricultural contracts downstream

·        Consider cooling towers

·        Who makes the final decision?

·        Consider changing the Basin Plan to identify the lower reach as warm water habitat


Temperature Profile Conditions in Lake Almanor:  PG&E provided a presentation on the modeling expected temperature profile conditions in Lake Almanor versus the actual measurements taken at various stations around the lake. (See Attachment 5 for presentation).  It was noted that the Chester Arm of Lake Almanor would not experience much impact because it is shallow and the majority of the water entering the Prattville structure comes from the Hamilton Branch area of the lake.  Natural variations are reflections of data taken annually and based on current conditions.  Additional stress with respect to existing conditions could be added with the inclusion of a thermal curtain.


The FS acknowledged that they accept the methodology utilized in preparing the report on potential downstream impacts to fisheries.  PG&E is evaluating how physical and biological habitat downstream will change with changes to water temperature.  The 2105LG also agreed to further evaluate Indian Creek restoration and re-operation at Caribou.  The Maidu Summit Group noted that they have passed a tribal resolution to oppose the thermal curtain.


Preliminary Cost Estimates: PG&E explained that several options had been explored included dredging alone, a hooded-pipe intake structure, and various shading strategies.  The curtain and dredging proposal is the least costly and the most effective.  The hooded pipe is more costly and doesn’t achieve the same benefits downstream.  Dredging alone and shading strategies didn’t provide the required cooling. 


The curtain at Prattville and dredging required is estimated to cost approximately $17.7 million.  Each curtain (2) in Butt Valley Reservoir would cost approximately 17 million for a total of roughly $53 million for construction alone.  Operation and maintenance costs are not included in those figures.


CEQA Process/Schedule and FERC Schedule Update: PG&E expects FERC to release a draft federal NEPA document in September.  That release will trigger a public comment and review period.  The final NEPA document is expected in 8-12 months.  Also in September, PG&E expects to release a Request for Proposal (RFP) to contract with a consultant to prepare the State CEQA document with SWRCB as lead agency.  The CEQA document will rely heavily on the contents of the NEPA document so is somewhat behind it to avoid duplication of effort.  At the same time, the final FERC decision and final NEPA document is dependent on the 401 Certification.  The CEQA process will also invite public participation including scoping meetings (in Chester) and draft document comment periods.  PG&E noted that they have filed for an application for 401 Certification, which starts a one-year clock for completion and will re-file as necessary, as the CEQA document is prepared.


Next Steps - Focus for Next Meeting:

The Facilitator noted a carry over action item from the last meeting:

ACTION ITEM 2:  Determine what Basin Plan designation Butt Valley Reservoir is managed for.

The following two questions related to the Basin Plan designation were offered to the SWRCB: 1) What procedures were used 3 years ago to designate the Rock Creek-Cresta reach cold water habitat? And 2) should the designation be changed to warm water habitat, particularly since FS is protecting hardhead and other warm water species?


The Facilitator reviewed an e-mail received from the SWRCB representative that indicated travel to Chester for the October meeting was not likely to be approved however participation via conference call may be an option.  The 2105LG agreed to further discuss other alternatives to achieving lower water temperatures downstream including the re-operation of Caribou 1 and 2 during August, stream course improvements in Indian Creek, cold water releases directly down Seneca via Canyon Dam, enhancement of spawning areas at Rock Creek-Cresta and fish access in tributaries under the railroad right of way (ladders, culverts, etc.). PG&E was also asked to show proof that salmon extended up into the Big Meadows area of the watershed.  The 2105LG agreed to the following upcoming meeting dates and locations:

Date                                         Location          Time

October 14                        2105LG                        Chester                         10am – 4pm

November 9                        2105LG                        TBD                        10am – 4pm


Attachment 1:                          List of Attendees

Dale Dawson*                        Butt Lake Anglers Association

Bill Dennison                          Plumas County Supervisor

Wayne Dyok                          MWH

Christi Goodman                     Plumas County

Bob Hawkins                          USFS

Tom Hunter                            Plumas County

Tom Jereb                               PG&E

Patti Kroen                             Kroen

Bob Lambert                           2105 Committee

Bruce McGurk                        PG&E

Lisa Randle                             PG&E

Steve Robinson                        MMC

Stuart Running                        PG&E

Aaron Seandel                         2105 Committee

Terry Simon-Jackson               USFS

Mike Taylor                            USFS

Scott Tu                                  PG&E

Janet Walther                          PG&E

Mike Wilhoit                           2105 Committee




* via telephone


Attachment 2 - September 2, 2004

Chester Memorial Hall

2105 LG

Proposed Agenda Items


Plumas County 2105 Committee


1)     2105 LG Protocol

a) For posting material on the 2105 Website 

                   Decision to label material that data is preliminary/draft, rather than seek approval of 2105 LG.

               b) Discussion of 2105 LG meetings following the intent of the Brown Act, including Public Notice?


2)     Review/Discussion of the 20 Questions that have been summarized by Mike Taylor. (Note: it will be helpful to have those mailed out in advance of the meeting.)


3)     PG&E summary of the studies that are planned as a means to assist the Rock Creek/Cresta (RC/C) in determining whether, or not to recommend the construction of the Prattville Intake Modification.


4)     Report on the recent ERC meeting; their intent and means of making Prattville Intake Modification “…affirmative recommendations”, as charged in the RC/C license.


5)     PG&E review of FERC Cost Effectiveness Guidelines. This is in reference to the 1999 curtain study that noted the estimated costs “….did not come close to meeting the FERC Cost Effectiveness Guidelines…”


6)     Discussion on the consequences of the ERC not reaching a consensus; e.g. “…a solution that all parties can live with….” 


7)     What is the process for searching for searching for an alternative method of reducing the water temperature at RC/C when a consensus on the construction of the curtain is not reached.


8)     Agency report on methodology review of the Scott Tu Temperature Model and results.  Have the agencies accepted, rejected, or are they requesting modification in the study methodology?


9)     Summary of the water temperature and fisheries reports by Scott Tu and Stu Running.

Review questions below, as a means of minimizing confusion about the costs and the positive and negative impacts to be expected from the construction of a Prattville Intake Curtain, two Butt Reservoir curtains and mitigation for Dissolved Oxygen (DO) reduction in Butt Reservoir.

·       What is the estimated total cost of installation of those projects?

·       What are the estimated annual maintenance costs for these projects?

·       Who will pay construction and maintenance costs? Will it be paid by PG&E ratepayers, or deducted from PG&E profits?

·       In simple terms, based on the installation of the Prattville Intake Curtain, two Butt Reservoir curtains and the mitigation the mitigation of the DO deficiency in Butt Reservoir:


                            a) What are the anticipated reductions in water temperatures from Lake Almanor to Butt Reservoir?

                            b) What is the anticipated warming of water temperatures as it passes through Butt Lake?

                                           c) What is the anticipated warming of water temperature as they pass through Belden Reach and             

                                               specifically the warming that occurs in the Caribou After Bay.

                                           d) What is the “best and worst case scenario” of the expected August temperatures at RC/C, during

                                              Dry, Critically Dry, Normal and Wet years?

                                           e) If Dry and Critically Dry years occur 1/3 of the time, or more and the curtain(s) and, as reported

by PG&E, are ineffective during those Water Type Years, what is the impact on the fish over the   long-term?


·       Based on current studies, summarize scientific knowledge on any detrimental damage to the fisheries and lake ecology at both Lake Almanor and Butt Reservoir. As example, we have been told to expect a reduction of 38% of the Lake Almanor Salmonid habitat and a reduction in the pond smelt that provides a significant food source to the Butt Reservoir trophy fish. How does the Thomas Payne report (See excerpts in attachment) apply to current understanding and knowledge?


·       How will the detriment to fisheries and total lake ecology be weighed by ERC and individual agencies in the over-all judgment on the “reasonableness” of the construction of the curtains?


·       What additional studies are needed to reach a conclusion on the “reasonableness” of curtain construction?



10)  Question for Forest Service: How can the agency defend both the warm water and cold water fisheries in a stream that has been designated as cold water fisheries?  



11)  Reports for next meeting, October 14 in Chester:

·       SWRCB--What were the procedures that led to the designation of the RC/C Reaches as Cold Water Fisheries?

        Does it appear that there are reasons to reconsider this designation?

        At what point will SWRCB provide their recommendations on the construction of thermal curtains?

·       PG&E—Are there any records that indicate that natural salmon runs were ever in the Big Meadows area?


Attachment 3



From November 25, 2002 Meeting Summary

Protocols Discussion

A draft protocol was prepared by the Protocols Sub-Committee and distributed to the participants in advance of the meeting for review.  The group discussed the role of confidentiality in this process and agreed that the process is not confidential but there may be aspects of a settlement negotiation that demand participants to trust each other and not ‘try the issues’ in the media. 



·        Participants could educate their constituents on efforts of the collaborative to reach agreement and provide their own views but not represent the views of other stakeholders.

·        Any proposed press release will first be approved by the 2105LG. 

·        After the participants have approved meeting summaries, the summaries can be distributed.  This distribution protocol would also apply to other documents.

·        New participants would be provided with and expected to comply with the Protocols and violations of the protocols would be discussed within the group on a case-by-case basis.


q      Action Item 1:  Mike Taylor of the Protocols Sub-Committee will draft additional language to revise the draft protocols to include an additional ‘not for attribution’ statement to be included under the personal conduct section of the protocols, and a discussion about the meeting summary/document distribution.  Participants will review the revised protocol prior to the December 18th meeting and provide specific comments at the December 18th meeting.

Due Date:  December 11, 2002



From Process Protocols (language added December 18, 2002):


Personal Conduct


a.  Respect: Participants will be afforded an opportunity to present their viewpoints.  Participants will listen to and be respectful of one another.


b.  Preparation:  Each participant will actively prepare for each meeting.  A participant will timely distribute any information it commits to provide, review all other information relevant to the agenda, and be prepared to effectively discuss each topic on the agenda.


c.  Commitments:  Each participant will keep its commitments.


d.  Disagreements:  All participants will seek mutual gain as the solution to each disagreement.


e. Communicating Interests:  Every participant will communicate its interests on topics under consideration.


f. Negotiation:  Participants who disagree with decisions, topics discussed or direction taken by the collaborative will not “try the proposal in the media” outside the collaborative process as a means of influencing decisions or discrediting collaborative participants.


g. Advice and Direction:  Participants may seek advice or direction from constituents or subject matter specialists within their organization on topics under discussion and keep constituents advised of topics discussed and decisions that have been reached,



Attachment 4


Prattville Temperature Issues

August 25, 2004


The following statements are a compilation of comments made at various public meetings in Chester and Chico, comments and concerns raised by Ron Decoto in a letter to FERC dated June 14, 2003 and recent comments by Bill Dennison in regard to the September 2, 2004 2101LG meeting.  The statements do not reflect all comments made on the subject of temperature reduction.  The statements are biological or physical in nature only and with one exception do not reflect any comments made concerning cost or economic impacts.


A common thread running through statements concerning the temperature curtain evaluation is that the statements nearly universally are defined in terms of the maximum predicted change in a physical attribute.  For example, it has been predicted that in certain situations the depth to the Lake Almanor thermocline will increase by 10 feet.  It is then assumed that the 10-foot change will occur every year.  What is vitally necessary for the full understanding of the potential changes that might take place is to define those changes in terms of water year type and summer meteorology.  By placing impact within the contest of climate we will be able to see how frequently an impact of a given magnitude is expected to occur and whether the predicted impact is within the range of variability currently experienced.


Questions are in no particular order of importance but generally start at Lake Almanor and move downstream.


1.      Cultural resource surveys have been conducted on the portion of Lake Almanor exposed during low lake levels.  There is a possibility that sites are located beneath the lake in the vicinity of the Prattville Intake.  Local tribes have knowledge of sites now inundated by Lake Almanor.  Photos of construction of the Prattville Intake would be beneficial in identifying probable sites.  Surveys, if undertaken, could take place under water.  How will local tribes be assured that removal of levee material and associated construction of the temperature curtain will not impact sites?


2.      As water is withdrawn from Lake Almanor, the thremocline perimeter decreases.  The change in perimeter is dependent on lake elevation at the beginning of summer, rate of water withdrawal, and summer meteorological conditions.  Based on the 33 years of synthesized reservoir operations, what is the total reduction in perimeter under various combinations of water year type, and cool, average, and above average summer meteorological conditions with and without the Prattville curtain?  Since water year type is not necessarily a good predictor of reservoir elevation at the beginning of the summer, use initial elevation if that gives more predictable results.


3.      Under current conditions, water withdrawn from Lake Almanor by the Prattville Inlet is composed of both warm and cold water.  Construction of the Prattville temperature curtain will result in withdrawal of cold water only in wet and normal years.  In Dry and Critically Dry years little cold water is available for withdrawal.  Surface water temperatures are predicted to change up to one-half degree Centigrade with installation of the temperature curtain.  Based on the 33 years of synthesized reservoir operations, what is the expected change in surface temperature under various combinations of water year type, and cool, average, and above average summer meteorological conditions with the Prattville curtain?  Compare the predicted surface temperatures to existing conditions for the 33 years of record.


4.      Under current conditions the depth to the thermocline in Lake Almanor during the summer is controlled somewhat by the non-selective nature of the Prattville Intake.  Construction of the temperature curtain at Prattville will result in selection of cold water at the expense of warm water.  The depth to the thermocline is expected to increase under certain combinations of summer temperature and water year type. Based on the 33 years of synthesized reservoir operations, what is the expected increase in the depth to the thermocline under various combinations of water year type, and cool, average, and above average summer meteorological conditions with and without the Prattville curtain?  Since water year type is not necessarily a good predictor of reservoir elevation at the beginning of the summer, use initial elevation if that gives more predictable results.   


5.      During the summer salmonids prefer a layer of water located just above the thermocline that meets temperature preferences and also contains adequate dissolved oxygen for survival.  As water is withdrawn from Lake Almanor, the volume of water occupied by salmonids shrinks necessitating movement by salmonids if they are to remain in preferred water temperature and dissolved oxygen conditions.  Where do salmonids go to take refuge from high water temperatures and low dissolved oxygen levels during stressful conditions caused by low lake level or unusually warm air temperatures?  Based on 33 years of reservoir operations, how are these places of refuge impacted with and without the Prattville curtain?


6.      Observations have shown that salmonids will move to the vicinity of springs located in Lake Almanor to take refuge from high summer water temperatures.  Based on the 33 years of synthesized reservoir operations how might access to the cold water discharging from the springs be impacted under various water year types and cool, average, and above average summer meteorological conditions with and without the Prattville temperature curtain?  Under existing conditions what proportion of salmonids are found in areas other that immediately surrounding springs? 


  1. Warm water preferring fish occupy the upper layers of Lake Almanor during the summer.  In some water year types and meteorological conditions the depth to the thermocline will increase as cold water is withdrawn at the Prattville Intake with installation of the Prattville temperature curtain.  In such years, will warm water preferring fish be favored in terms of individual growth or numbers?


  1. Currently lake Almanor is occupied by both warm and coldwater fish each occupying preferred habitat conditions.  Water year type and meteorological condition variability would appear to favor one or the other at times.  By utilizing the 33 years of synthesized operations, is it likely that warm water fish abundance would change with construction of the Prattville curtain?


  1. During the summer, water in Lake Almanor is heated from above by solar radiation and convection and cooled from the bottom by the lakebed causing temperature stratification in the lake.  The temperature stratification is also equivalent to stratification by density as well with the warmer and less dense water lying on top of the cooler, and more dense water.  The Prattville temperature curtain if deployed would extract cool water from below the thermocline.  Would withdrawal of cold water initiate currents within the coldwater pool that would result in unequal distribution of cold water or is the coldwater pool of equal consistency throughout the reservoir?


  1. During the summer surface inflow, and to some extent depending on location and the elevation of Lake Almanor is cooler than the receiving water.  As the cool water descends through the warmer lake water, drag is exerted on the adjacent warm water entraining some of that water in a downward motion.  The warm water is replaced to some extent by upwelling cold water.  What changes in biological activity and water chemistry would be expected at these inflow points with operation of the Prattville temperature curtain?


  1. During low inflow years, Lake Almanor does not fill to the extent it does in wet years.  As water is drawn into the Prattville intake in low elevation years, the proportion of warm versus cold water increases since the thermocline elevation will be quite close to the inlet elevation.  In Dry and Critically Dry years what is the difference in volume of cold water removed with and without the Prattville temperature curtain?  Would differences be better illustrated if withdrawal were described in calories rather than volume of water?


  1. The Chester arm of Lake Almanor is quite shallow compared to the Hamilton Branch arm.  The bottom of the reservoir in the Chester area was once a rather extensive meadow with a gentle slope.  Residents have commented that aquatic plants have been a problem in the past.  If the Prattville temperature curtain is constructed the perimeter of the lake will not change since the quantity and timing of water withdrawal from the lake will be the same with or without the Prattville curtain.  The surface temperature of the lake and depth to the thermocline will increase under some conditions.  Will aquatic plant volume or area increase with operation of the temperature curtain due to the presence of warmer water in contact with the reservoir bottom under certain conditions?  Which combinations of water year type and summer meteorological conditions will result in additional aquatic plant growth?  What is the maximum rooting depth of aquatic plants commonly found in Lake Almanor?


  1. Will the withdrawal of cold water and the increase in depth to the thermocline in some years result in increased algae production in Lake Almanor?  Would additional algae reduce the depth to the thermocline by intercepting sunlight?


  1. The dissolved oxygen content of cold water withdrawn from Lake Almanor will be quite low.  When released into Butt Valley Reservoir at the Butt Valley Powerhouse, the cooler, dissolved oxygen deficient water is likely to not mix readily with Butt Valley Reservoir water.  What is the impact of the release of oxygen deficient coldwater on the Butt Valley Reservoir fishery and what mitigating measures could be taken to increase the dissolved oxygen content of the water?


  1. As coldwater from Lake Almanor passes through Butt Valley Reservoir warming takes place negating a portion of the coldwater benefit.  Temperature modeling has demonstrated that it is possible to recapture a portion of temperature gain by construction of a temperature curtain at the Caribou 1 and 2 intakes as well as the tailrace of Butt Valley Powerhouse.  The recapture is greatest with two curtains in Butt Valley Reservoir.  What is the estimated cost of constructing curtains at Butt Valley Powerhouse and near the Caribou 1 and 2 intakes?  Black and Veatch has provided the estimated cost of constructing the Prattville temperature curtain.  What is the estimated annual cost of maintaining the curtains?  Will replacement be necessary during the term of the license?


  1. The Prattville temperature curtain if constructed would occupy approximately 14 of the 27,000 acres or five one-hundredths of one percent (1 in 1,929) of the surface area of Lake Almanor.  On an expansive scale the curtain is insignificant.  The curtain may have aesthetic impacts if seen from nearby residences.  Would the curtain be visible from nearby residences?  Would the curtain add to the visual impact of the existing intake structures and associated PG&E on-shore facilities?  Are their mitigating measures that would reduce the visual presence of the curtain structure?


  1. Currently large numbers of Japanese pond smelt pass through the Prattville tunnel and Butt Valley powerhouse to emerge as chum for brown trout.  With construction of the temperature curtain, the pond smelt will no longer be drawn into the tunnel.  What is the effect of reduction of chum to Butt Valley Reservoir and the increase in numbers of pond smelt remaining in Lake Almanor?  If the Prattville temperature curtain were constructed in a manner to allow opening of the curtain, would Japanese pond smelt be drawn into the Prattville Intake? 


  1. A fixed curtain installed at Prattville will withdraw cold water yearlong.  Is there a combination of timing and selective withdrawal that minimizes the additional depth to the thermocline experienced with the fixed curtain?


  1. Would additional warm water under certain combinations of water year type and summer meteorological conditions impact existing programs designed to improve fish habitat in Lake Almanor?  Is the impact positive or negative?  If negative, what is the expected frequency of negative impact years?


  1. What water quality, aquatic habitat and fish monitoring will take place in order to quantify changes in Lake Almanor and Butt Valley Reservoir due to withdrawal of cold water.  Is it possible to modify the existing aquatic and water quality program or will new monitoring be necessary?


  1. How might wind, waves and ice impact the Prattville temperature curtain?


  1. If it is assumed that the temperature curtain with levee removal takes place in Lake Almanor and temperature curtains are constructed at Butt Valley Powerhouse and at the Caribou inlets and mitigation of dissolved oxygen deficiencies occurs:

·       What are the anticipated reductions in water temperature at Butt Valley Powerhouse?

·       What is the anticipated warming of water temperature as it passes through Butt Valley Reservoir?

·       What warming occurs in the Belden Forebay?

·       What is the anticipated warming of water temperature in the Belden reach?

·       What is the “best and worst case scenario” for the expected August temperature in the Rock Creek and Cresta reaches during Wet, Normal, Dry, and Critically Dry water year types?


  1. Modeling of the effectiveness of the Prattville temperature curtain in reducing downstream stream temperature has demonstrated that any combination of curtains in Lake Almanor and Butt Valley Reservoir will reduce downstream water temperature under some but not all situations.  Based on the 33 years of synthesized reservoir operations, what is the expected reduction in stream temperature under various combinations of water year type, and cool, average, and above average summer meteorological conditions in the Rock Creek and Cresta reaches?


  1. Reductions in stream temperature in the Rock Creek and Cresta reaches will not occur in all water years.  It appears that reductions in temperature will occur in Wet and Normal years with Dry and Critically Dry years receiving little if any temperature reduction.  Since the area climate tends to exhibit precipitation extremes, Dry and Critically Dry years frequently occur.  What physical and biological parameters will be used to monitor aquatic environment response to installation of temperature curtains?  How will improvements in aquatic health be quantified?