[Federal Register Volume 62, Number 32 (Tuesday, February 18, 1997)]
[Proposed Rules]
[Pages 7201-7203]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-3946]



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DEPARTMENT OF THE INTERIOR

Bureau of Reclamation

43 CFR Part 418

RIN 1006-AA37


Adjustments to 1988 Operating Criteria and Procedures (OCAP) for 
the Newlands Irrigation Project in Nevada

AGENCY: Bureau of Reclamation, Interior.

ACTION: Proposed rule; availability of supplementary information and 
extension of comment period.

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SUMMARY: This document announces the availability of detailed 
information on the computerized modeling run of Newlands Project 
operations used in developing the proposed rule, and the availability 
of summary information on other operations modeling runs considered. 
Also, the comment period on the proposed rule is extended by 60 days. 
The proposed rule adjusting the 1988 OCAP for the Newlands Irrigation 
Project was published in the Federal Register on December 9, 1996 (61 
FR 64832). Written comments were requested by February 7, 1997. Several 
agencies and individuals have requested additional information and 
asked that the comment period be extended to provide additional time 
for the collection and analysis of relevant information and preparation 
of comments. As a result of these requests, the comment period has been 
extended until April 8, 1997.

DATES: Written comments should be submitted to be received by April 8, 
1997. All comments received on or before that date will be considered 
and addressed in the Final Rule. Comments received after that date will 
be reviewed and considered as time allows.

ADDRESSES: Comments should be to the following address: Adjusted OCAP, 
Truckee-Carson Coordination Office, 1000 E. William Street, Suite 100, 
Carson City, NV 89701-3116. Supplemental information is available at 
the same address.

FOR FURTHER INFORMATION CONTACT:
Jeffrey Zippin, Team Leader, Truckee-Carson Coordination Office, (702) 
887-0640, or Ann Ball, Manager, Lahontan Area Office, (702) 882-3436.

SUPPLEMENTARY INFORMATION: 

Additional Information

    Several individuals, organizations, and agencies have requested 
additional information regarding the proposed Adjustments to the 1988 
OCAP. These parties want to see the data developed using the Truckee 
River operations model to examine in detail how the proposal may affect 
the Newlands Project water supply. The following information is 
available:
    <bullet> A single page summary of modeling runs for the 1988 OCAP, 
the proposed Adjustments to the 1988 OCAP, and other modeling runs 
considered. This document is identified as ``Multiple Modeling Runs 
Summary''
    <bullet> A 36-page summary of the ``174,000 acre-foot Storage 
Target Run'' for the proposed rule including 29 parameters relating to 
the Truckee River reservoir releases, Truckee and Carson River stream 
flow, Truckee Canal, Truckee Division, Lahontan Reservoir, Carson 
Division, Pyramid Lake, and Cui-ui. This document is identified as 
``Proposed 1988 OCAP Adjustments Modeling Summary.''
    <bullet> The 400-plus-page complete modeled output used to develop 
the proposed rule and identified as the ``174,000 acre-foot Storage 
Target Run.'' The data include monthly results for approximately 100 
parameters over the 94-year period 1901-1994.

Questions and Answers

    Two public workshops were held in Fallon and Fernley, Nevada, 
January 8 and 9, 1997, respectively, to describe and answer technical 
questions about the proposed adjustments to the 1988 OCAP. The 
following questions and answers taken from the public workshops and 
from additional questions received on the proposed rule are presented 
below to assist reviewers in better understanding and commenting upon 
the proposed rule.
    1. Q. Did the computer modeling runs used in developing the 
proposed rule include precipitation, runoff, or snowpack forecasts?
    A. Administration of the OCAP every year relies on real-time runoff 
forecasts. However, the computer modeling uses historical records of 
Truckee and Carson River hydrology, including precipitation and 
snowpack runoff, and an error factor to simulate forecasting errors in 
assessing how the proposed rule would affect Newlands Project 
operations and water supply over a 94-year period of record.
    2. Q. The model uses a total Project diversion demand of 294,000 
acre-feet. Does this demand include both Carson Division and Truckee 
Division demand?
    A. Yes, the 294,000 acre-foot demand includes active water rights 
in both Divisions.
    3. Q. In the computer model, the ``beginning cui-ui'' number (adult 
females) remains constant in the modeling runs. Why is a constant value 
used?
    A. The beginning cui-ui number is a common starting number in the 
cui-ui model. It is a calculated number, approximately 50,000, from the 
Cui-ui Recovery Plan. Because all the modeling is essentially a 
hindcast, it uses historical hydrology and historical conditions in the 
cui-ui population as a starting point. By using a common beginning, we 
can evaluate the effects of different water management actions on cui-
ui. This is the basis for comparison of cui-ui population response to 
various water regimes on the Truckee River.
    4. Q. Should the computer model be changed to reflect the increased 
cui-ui population of today?
    A. No, it is not necessary to use the latest cui-ui numbers in 
evaluating relative impacts of different modeling runs. It is more 
important to use a common beginning because we are trying to compare 
the effects of different modeling runs on cui-ui. In these modeling 
runs, the starting number represents an initial condition. Just as in a 
bank account, you start with an initial deposit and then adjust the 
balance over time for deposits, withdrawals, interest, and fees. You 
don't go back and adjust the initial deposit just because you have more 
money in the bank today.
    5. Q. Does the 294,000 acre-foot demand include water rights 
acquired to restore Stillwater National Wildlife Refuge and Carson Lake 
and Pasture wetlands?
    A. Yes, it includes wetland water rights acquired to date which are 
approximately 5,200 acres of Carson Division agricultural water rights.
    6. (a) Q. Does the model assume wetland water rights are used at 
2.99 acre-feet per acre?
    A. Yes, the modeling assumes a use rate of 2.99 acre-feet per acre.
    (b) Q. What happens to the additional 0.51 or 1.51 acre-feet per 
acre?
    A. The additional 0.51 or 1.51 acre-feet per acre stays in Lahontan 
Reservoir where it does two things. It increases the Carson Division 
water supply to all water users in shortage years; in full water years 
it remains in Lahontan Reservoir and reduces Truckee River diversions 
to the Reservoir in subsequent years.
    7. Q. Are wetland water rights assumed to come out of the Truckee 
River diversions to the Project, increasing shortages to the Carson 
Division of the Project?
    A. No, wetland water rights are acquired, active, agricultural 
water rights from within the Carson Division or from sources on the 
Carson River above Lahontan Reservoir. Water rights

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acquired within the Carson Division share the same amount of Truckee 
River water, if any, in a given year as the rest of the Carson 
Division.
    8. Q. Do the new conveyance efficiency targets include the delivery 
to Stillwater National Wildlife Refuge and Carson Lake and Pasture?
    A. Yes, the conveyance efficiency targets apply to all water users, 
including the wetlands.
    9. Q. If Project facilities are altered or new facilities 
constructed to aid water deliveries to the wetlands, will conveyance 
efficiency requirements be adjusted to account for such changes?
    A. Carson Division conveyance efficiency measures the amount of 
water delivered to headgates as a percentage of the Lahontan Reservoir 
water released to serve those water rights. Changes in conveyance 
efficiency requirements could be considered in the future. It is 
premature to consider how changes to the wetlands water delivery system 
might affect conveyance efficiencies until such time as we know how 
much water delivery is affected, the stage of the water acquisition 
program, the geographic distribution of acquisitions, the degree to 
which entire canal/lateral systems are retired because appurtenant 
water rights have been acquired, conversion of Project irrigated lands 
and water use to development or municipal and industrial (M&I) use, and 
conveyance efficiency improvements made. At this time, it is impossible 
to know whether conveyance efficiencies would improve or decline from 
changes in the water delivery system.
    10. Q. How was the proposed 65.7 percent conveyance efficiency 
requirement determined.
    A. The 65.7 percent conveyance efficiency is an example based on 
1995 Project data. The Bureau of Reclamation (BOR) constructed a linear 
extrapolation comparing the conveyance efficiency required in the 1988 
OCAP for 64,850 water-righted acres with what would be required for 
59,075 water-righted acres.
    11. Q. Does the proposed conveyance efficiency requirement assume 
that the Truckee-Carson Irrigation District (TCID) will line canals?
    A. No specific assumptions are made on the methods by which TCID 
will improve Project conveyance efficiency. Canal lining would be one 
way to improve conveyance efficiencies, as would better water 
measurement. Additional information on conveyance efficiency has been 
provided to TCID and other interested parties in the BOR's 1994 
efficiency study for the Newlands Project. That document is available 
at the address above.
    12. Q. Is the proposed Lahontan Reservoir storage target of 174,000 
acre-feet a limit on how much water can be stored in the Reservoir at 
any time?
    A. No, the proposed end-of-June storage target of 174,000 acre-feet 
would be used to determine if water would be needed from the Truckee 
River as a supplemental supply to Carson River inflow to the Reservoir. 
That target does not limit how much water can be stored in Lahontan 
Reservoir. Above the target, Carson River water may fill the Reservoir 
to its capacity.
    13. Q. Since the adjustment to the Lahontan Reservoir storage 
targets is based in part on the reduced Project demand when compared to 
the 1988 OCAP, what will happen if the water transfer litigation 
results in greater acreage and more water demand?
    A. This is something that bears watching and could be considered 
for changes in the future. The outcome of the water transfer litigation 
is unknown and may not be resolved for several years. Other changes 
within the Project may affect water demand, including but not limited 
to continued development of agricultural lands, changes in demand as 
the FWS acquires water (see number 4.b above), and water dedications to 
future M&I use. At this time, it is not possible to say whether future 
demand will increase or decrease, or know the magnitude of the change.
    14. Q. Modeling for the 1988 OCAP indicated four shortage years for 
the Project. Why do the proposed Adjustments to the 1988 OCAP show nine 
shortage years?
    A. The 1988 OCAP modeling used the hydrology for the 80-year 
period, 1901-1980, which included shortages in drought years 1931, 
1934, 1961, and 1977. The proposed Adjustments to the 1988 OCAP are 
modeled using the hydrology from the 94-year period 1901-1994. The 14-
year period 1981-1994 included five additional drought years (1988, 
1990, 1991, 1992, and 1994) which adds five more shortage years. When 
the 1988 OCAP is examined using the 94-year hydrology, there are also 
nine shortage years.
    15. Q. Why was the end of June storage target in Lahontan Reservoir 
reduced by 19 percent (174,000 acre-feet versus 215,000 acre-feet) when 
the project acreage is only 9 percent less than anticipated in the 1988 
OCAP (59,075 acres versus 64,850 acres)?
    A. The proposed storage target adjustments attempt to (among other 
things) more closely balance the water supply to the demand in the 
Carson Division. The demand is based on water-righted, irrigated acres 
to be served. The supply is composed of inflow to Lahontan Reservoir 
from the Carson River and water from the Truckee River as a 
supplementary supply. In the proposed rule, the Lahontan storage 
targets, which govern Truckee River diversions, are adjusted so that 
the decrease in average water supply is commensurate with the current 
demand. Just a percentage comparison of storage targets and acreage 
does not tell the whole story. The proposed 19 percent change in the 
storage target for regulating the supplemental supply is not comparable 
to the change in demand based on water-righted, irrigated acres. For 
example, even if demand were reduced 100 percent based on zero 
irrigated acres, there would still be enough water supply from the 
Carson River inflow alone to serve tens of thousands of acres. In 
developing the proposed rule, percentage reductions in storage targets 
were considered but those targets did not adjust the supply to match 
the current demand. Based on modeled averages, Carson Division water 
supply in the proposed Adjustments to the 1988 OCAP compared to under 
the 1988 OCAP assumptions indicates a decrease of 7 percent (264,120 
acre-feet versus 284,180 acre-feet). As noted in the question, the 
acreage difference is 9 percent less.
    16. Q. Why does modeling show a difference in the proposal between 
the water shortages in the Carson Division between the Fallon Paiute-
Shoshone Tribe and the rest of the water users?
    A. The difference in shortage between the Fallon Tribe and the rest 
of the Carson Division results from the cap on their water use. During 
shortages, Project water deliveries have been based on total water-
righted acres. The Fallon Tribe total water right is 19,041 acre-feet, 
but use is capped at 10,587.5 acre-feet. [Public Law 101-618, section 
103(c)] The Tribe's supply of water in a water short year is based on 
its water right, thus in any shortage year down to a 56 percent year, 
the Tribe would receive all of its water permitted by the use cap.

Extension of the Comment Period

    The comment period on the proposed Adjustments to the 1988 OCAP 
rulemaking is extended to allow parties to consider the supplemental 
material being made available through this notice, and because of 
flooding in western Nevada. The Truckee, Carson, and Walker Rivers in 
Nevada began flooding on January 1, 1997, and continued under flood 
watches and warnings in some river segments for several weeks. Some 
parties interested in or affected by the proposed

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rulemaking have been directly affected by the flooding. Many more 
parties, including the public, and local, State, and Federal agencies 
wish to make comments on the proposed rule but have been preoccupied in 
flood water management operations and/or flood recovery activities. The 
Truckee-Carson Coordination Office has received many written requests 
for extension, all citing the floods as affecting the time they have 
available to review the proposed rule and provide comments. An 
additional 60 days would allow all interested parties to review the 
proposed rule and supplemental information, and prepare and submit 
comments.
John Garamendi,
Deputy Secretary.
[FR Doc. 97-3946 Filed 2-14-97; 8:45 am]
BILLING CODE 4310-RK-M