| af
or AF: |
Acre
foot. The amount of water required to flood one acre one foot
deep.
|
| Confining
Layer: |
A
relatively impermeable underground layer, usually of clay, which restricts
vertical movement of groundwater. In Owens Valley, confining
layers of clay generally extend from the toes of the alluvial fans
along the Sierra Nevada east to the toes of the fans along the White
and Inyo Mountains. The Conceptual
diagram of the Owens Valley Aquifer (modified from Figure 9-7
) of the EIR to the LTWA shows a good visualization of confining layers.
|
| Dispute
Resolution: |
A procedure
for resolving disputes regarding implementation of the LTWA.
It is defined in section XXVI. of the LTWA. The MOU to the EIR
of the LTWA has its own Dispute Resolution procedure established (Section
VI. MOU)
|
| DWP:
|
Los
Angeles Department of Water and Power. The DWP website is at
http://www.ladwp.com/ladwp/homepage.jsp
|
| EIR: |
Environmental
Impact Report. The California Environmental Quality Act requires
that an EIR be written for projects which may significantly impact
the environment. After DWP completed the second barrel of the
aqueduct in 1970, Inyo County sued under CEQA to force DWP to write
an EIR for the groundwater pumping used to fill the expansion of the
aqueduct. The first two EIR's were rejected as inadequate by
the court. The third EIR, written to cover both the pumping
for the aqueduct and the LTWA, was also found to be inadequate.
Rather than start all over on a fourth EIR, however, the court invited
The Owens Valley Committee, the Range of Light Group of the Sierra
Club, the California Department of Fish and Game and the California
State Lands Commission to be "friends of the court"
and negotiate with DWP and Inyo County an MOU to remedy the deficiencies
of the EIR to the LTWA
|
| Green
Book: |
The
technical appendix to the LTWA. "The location of each management
area, vegetation monitoring site, and each monitoring well; the wells
linked to each vegetation monitoring site; the method for locating
additional monitoring sites and monitoring wells; the type of monitoring
to be conducted at each site; and the standardized procedures for
analysis and interpretation of monitoring results, including the determination
of available soil water and the amount of soil water required by vegetation,
are set forth in a technical document called a "Green Book."
(Section I.E LTWA). The full text of the Green Book is available
at http://www.inyowater.org/Water_Resources/Green
Book 2000.PDF
|
| Hydrograph: |
Graph
in which water table depths are plotted over time. Water table
depth is usually plotted on the Y (vertical) axis while time is usually
plotted on the X (horizontal) axis.
|
| ICWD:
|
Inyo
County Water Department. The ICWD website is at http://www.inyowater.org
|
| LTWA:
|
Inyo-Los
Angeles Long Term Water Agreement The full text of the LTWA
is available at http://www.inyowater.org/Water_Resources/water_agreement/default.html
|
MOU:
Memorandum of Understanding. The LTWA was negotiated in 1990:
1) to settle CEQA litigation initiated in 1972 over deficiencies in
the EIR for the pumping to fill the second barrel of the Los Angeles
Aqeduct; and 2) to insure future groundwater management would avoid
significant environmental impacts while providing a reliable supply
of water to Los Angeles. The EIR for the LTWA itself, however,
was found to be deficient by the court with jurisdiction over the
original CEQA litigation. Rather than throw out the LTWA and
start from scratch to resolve the original CEQA litigation, the court
invited The Owens Valley Committee, the Range of Light Group of the
Sierra Club, the California Department of Fish and Game, and the California
State Lands Commission to be "friends of the court"
and negotiate with DWP and Inyo County an MOU to remedy the deficiencies
of the EIR to the LTWA. After seven years of negotiation, an
MOU was signed among these six groups. This 1997 MOU is the
one to which references in this website to "the MOU" refer.
The full text of the MOU is available at http://www.inyowater.org/Water_Resources/mou/default.html
The 1982 MOU under which the Inyo-LA Standing Committee was formed is a different MOU.
|
| On/Off:
|
The pumping
management protocol in the Green Book is often referred to as "On/Off
management". The Green Book contains complicated procedures
for determining whether any given well can be pumped (on) or must
not be pumped (off). The basic idea is that a pump can be turned
on only when there is sufficient soil moisture to support vegetation
at the monitoring site associated with the pump. Pumps can
be go into On status any time of the year. Pumps can go into
Off status only on July 1, or October 1 of any given year. Both
ICWD and DWP agree that the On/Off protocol is inadequate to meet
the goals of the LTWA. Unfortunately, as of April 2004 neither
ICWD nor DWP have proposed an alternative.
|
| Permanent
monitoring site: |
Sites
where plant cover and species composition, and soil moisture are measured
every year. As of March 2004 there are 33 permanent monitoring
sites. 22 of the sites are associated with particular wells.
Data on soil moisture and plant cover from each monitoring site are
used in the on/off protocol to determine whether the wells associated
with each monitoring site will be pumped or not. The remaining
11 permanent monitoring sites are in areas not impacted by pumping
and are used as controls i.e. for comparisons with those in pumped
areas.
|
| Screened:
|
The portion
of a well that is not sealed off from the surrounding rock is considered
to be screened. The screening depth of a well is the depth at
which the sealing ends and the well is open to draw in water from
the surrounding material. Wells constructed since the 1970's
have generally been sealed where they penetrate shallow aquifers and
screened only in deep aquifers under confining layers.
|
| Standing
Committee: |
| The
Inyo-LA Standing Committee was formed pursuant to an MOU signed September
2, 1982. DWP representatives on the Standing Committee shall
include at least one (1) member of the Los Angeles City Council, the
Administrative Officer of the City of Los Angeles, two (2) members
of the Board of Water and Power Commissioners, and three (3) staff
members. |
| Inyo
County representatives on the Standing Committee shall be at least
one (1) member of the Inyo County Board of Supervisors, two (2) Inyo
County Water commissioners, and three (3) staff members. |
Inyo
County shall have one (1) vote and Los Angeles shall have one (1)
vote (Section II. LTWA).
|