[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]
[[Page 7201]]
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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:
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''
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.''
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
