Trinity River Restoration Program, Weaverville, CA, 26560-26561 [E6-6794]

Agencies

• DEPARTMENT OF THE INTERIOR
• Bureau of Reclamation
• Reclamation Bureau

[Federal Register Volume 71, Number 87 (Friday, May 5, 2006)]
[Notices]
[Pages 26560-26561]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E6-6794]


-----------------------------------------------------------------------

DEPARTMENT OF THE INTERIOR

Bureau of Reclamation


Trinity River Restoration Program, Weaverville, CA

AGENCY: Bureau of Reclamation, Interior.

ACTION: Notice and correction regarding implementation of program.

-----------------------------------------------------------------------

SUMMARY: On December 19, 2000, the Secretary of the Interior 
(Secretary) signed the Record of Decision (ROD) implementing the 
Trinity River Restoration Program (Program), which adopted the 
Preferred Alternative analyzed in the Trinity River Mainstem Fishery 
Restoration Final Environmental Impact Statement (FEIS). The Department 
of the Interior (Department) has identified a discrepancy in the 
description of the hydrologic forecast used in the annual flow regime 
component of the Program. The impacts analysis in the FEIS was based 
upon modeling the historic inflows into the Trinity River watershed 
above the Trinity Dam and categorizing this data into five water-year 
classes. These classes and their probability of occurrence were 
displayed in the FEIS and are repeated below:

                             Table A.--Values from Final EIR/EIS Table 1 (page C-3)
                                                 [WY 1912-1995]
----------------------------------------------------------------------------------------------------------------
                                                                   Trinity River   Annual runoff
                        Water-year class                          allocation  (T   into Trinity   Probability of
                                                                        AF)         Lake (TAF)      occurrence
----------------------------------------------------------------------------------------------------------------
Critically Dry..................................................             369            <650            0.12
Dry.............................................................         453,000        650-1025            0.28
Normal..........................................................         647,000       1025-1350            0.20
Wet.............................................................         701,000       1350-2000            0.28
Extremely Wet...................................................         815,000           >2000            0.12
Average.........................................................             594
----------------------------------------------------------------------------------------------------------------

    This discrepancy occurred because the FEIS narrative in Appendix C 
incorrectly references use of a 90% exceedence forecast in determining 
classes for the upcoming water year. Use of the 50% exceedence forecast 
more accurately reflects the occurrence of water year types identified 
in the chart above and more closely approximates the impact analysis in 
the FEIS.
    The corrective action taken by the Department will ensure that any 
potential impacts from implementation of the Program are consistent 
with the FEIS. This correction does not require any new action or the 
modification of an existing action, so no further National 
Environmental Policy Act (NEPA) analysis is necessary. Moreover, 
correcting this error in the FEIS Appendix C narrative will have no new 
impacts on the goals of the Program, or on water and power users beyond 
what has already been disclosed and analyzed in the FEIS, and there is 
no change in the ROD itself. By making this correction now, 
Reclamation's actions with regards to determining the water year type 
for the 2006 water year will be consistent with the impacts analysis 
approved in Westlands Water District v. Department of the Interior 366 
F.3d 853 (9th Cir, 2004). In summation, the NEPA and Trinity River Flow 
Evaluation Study (TRFES) analysis are unchanged and Reclamation is 
simply ensuring that implementation of the Program reflects the 
analyses used in the FEIS and ROD.

DATES: The Secretary is not proposing to take any new action as a 
result of this Federal Register notice. Accordingly, the Department is 
not establishing a specific date by which comments must be submitted.

ADDRESSES: You may submit written comments to Douglas Schleusner, 
Executive Director, Trinity River Restoration Program, P.O. Box 1300,

[[Page 26561]]

1313 South Main Street, Weaverville, California 96093.

FOR FURTHER INFORMATION CONTACT: Douglas Schleusner at (530) 623-1800.

SUPPLEMENTARY INFORMATION: On December 19, 2000, the Secretary, with 
concurrence of the Hoopa Valley Tribe, signed the ROD for the Program. 
The decision outlined in the ROD called for the implementation of the 
Preferred Alternative, which incorporated the recommendations developed 
in the TRFES and evaluated in the FEIS under the Flow Evaluation 
Alternative, coupled with additional watershed protection efforts 
identified in the Mechanical Restoration Alternative contained in the 
FEIS.
    A component of the Flow Evaluation Alternative is a flow regime 
that is intended to achieve various anadromous fishery habitat 
objectives associated with meeting the goals of the Program. The 
recommended flow regime and the water year class, which determine the 
volume of water available in a given year, were developed from historic 
annual hydrologic records of the Trinity River watershed. Under the 
ROD, the water year class for any given year is determined based on the 
total water runoff (unimpeded flow) forecasted to occur in the Trinity 
River watershed above Trinity dam, as of April 1 of each year. The 
water year classes and expected probability of occurrence are stated in 
the chart above.
    Appendix C of the FEIS sets out the process for the water year 
class forecast. On page C-4 the FEIS states: ``Annual basin runoff is 
calculated by summing the amount of runoff that has occurred form 
October 1 until April 1 and a volume of water that Reclamation 
forecasters predict (90 percent probability of exceedence) will run off 
during the months remaining in the water year (i.e. April through 
September) using the April 1 runoff forecast projection from the 
California Cooperative Snow surveys, California Department of Water 
Resources, Bulletin 120. Total water runoff is then compared to the 
ranges in Table 1 [of Appendix C] to designate the water year class.''
    In fact, the 50% exceedence value enables a substantially more 
accurate forecast of a water year class than the 90% exceedence value. 
Program staff have determined that use of the 90% exceedence criterion 
would under-predict (i.e. predict a drier year than actually occurred) 
the actual water year class in 18 of the 49 years from which the 
necessary records were available to conduct the analysis. Of the 18 
years, 8 years had later rain events in May or June.
    The results of such under-prediction would negatively affect the 
successful implementation of the Program. The identification and 
evaluation of impacts associated with the alternatives evaluated in the 
FEIS were based on the historic hydrology of the Trinity River, and how 
that water was allocated between diversions to the Central Valley 
Project and flows down the Trinity River. The modeling of impacts 
associated with each alternative, especially with regard to impacts to 
water supply delivery and hydropower generation by the CVP for any 
given year class, was based upon what actually happened in that water 
year class historically, not upon what an April 1 forecast using a 90 
percent exceedence criterion would have been.
    As documented in the Final Report on the TRFES and in the FEIS, the 
majority of the geomorphic work to restore and maintain anadromous 
fishery habitat in the mainstem of the Trinity River is expected to 
occur during ``wet'' and ``extremely wet'' years. Continued use of the 
90 percent exceedence criterion would result in a failure to experience 
the number of wet years anticipated by the ROD over the extended 
implementation of the Program, which would jeopardize the success of 
the Program.
    Reclamation is correcting the reference to the April 1 exceedence 
criterion from 90 percent to 50 percent, based upon investigations by 
Program staff, with input from the Hoopa Valley Tribe and the Trinity 
Adaptive Management Working Group (TAMWG). Program staff determined 
that use of the 50 percent criterion would correctly predict 44 of 49 
of the years for which the necessary records were available. 
Additionally, of the remaining years, three resulted in underestimating 
the year class and two resulted in overestimating the year class. The 
resultant accuracy rate when using the 50 percent exceedence criterion 
is approximately 90 percent when compared to the historic record, with 
the errors almost balanced in over and under predicting the water year 
class. Thus the 50 percent exceedence criterion is approximately 90 
percent accurate while the 90 percent exceedence criterion success rate 
is only slightly above 63 percent, with the errors consistently 
resulting in a prediction that is drier than that which ultimately 
occurs. This correction will not affect the decision adopted in the ROD 
or the supporting environmental analysis in the FEIS.
    The Department hereby corrects the process by which the water year 
class is identified in the FEIS for the Trinity River Mainstem Fishery 
Restoration Program in order to implement the alternative selected in 
the ROD for the Program. The correction replaces the 90 percent 
exceedence criterion used by Reclamation to forecast runoff in the 
Trinity River watershed as of April 1 of each year, with a 50 percent 
exceedence criterion.

Submitting Comments

    The Secretary is not proposing to take any new action as a result 
of this Federal Register notice. Accordingly, while the Department 
welcomes comments, the Department is not establishing a specific date 
by which comments must be submitted. Public comments on other aspects 
of this Adaptive Environmental Assessment and Management (AEAM) program 
may always be submitted to the TMC, the TAMWG, or the Executive 
Director.
    Our practice is to make comments, including names and home 
addresses of respondents, available for public review. Individual 
respondents may request that we withhold their home address from public 
disclosure, which we will honor to the extent allowable by law. There 
also may be circumstances in which we would withhold a respondent's 
identity from public disclosure, as allowable by law. If you wish us to 
withhold your name and/or address, you must state this prominently at 
the beginning of your comment. We will make all submissions from 
organizations or businesses, and from individuals identifying 
themselves as representatives or officials of organizations or 
businesses, available for public disclosure in their entirety.

Frank Michny,
Regional Environmental Officer, Mid-Pacific Region.
 [FR Doc. E6-6794 Filed 5-4-06; 8:45 am]
BILLING CODE 4310-MN-P