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Mono Basin: Other Out Flows

Vorster 's model combines several flows out of the basin into an aggregate flow of 34 KAF/yr. The flow is assumed to reamain constant over time, regardless of changes in the size of the lake. Vorster describes these flows as follows:

Ground Water Export
7.3 KAF/yr
An underground conduit transports surface water from Grant Lake through the Mono Craters and into the Owens River watershed. Vorster explains that this conduit intercepts groundwater like a "giant horizontal well." Vorster uses a constant value of 7.3 KAF/yr as a "steady state average" of this ground water flow.

Net Grant Lake Evaporation
1.3 KAF/yr
Grant Lake is a small reservoir built by the LADWP to impound the flow of Rush Creek. Vorster (1980, 68) reports the reservoir's usable capacity at around 48 KAF. If full, the lake's surface would cover 1,000 acres, but the normal area might be around 800 or 900 acres. Vorster estimates the net evaporation rate at Grant Lake to be around 20 inches/yr or 1.67 ft/yr.

Exposed Lake Bottom Evaporation
12 KAF/yr
As Mono Lake recedes from its historical high stand of 6,428 feet, much of the exposed lake bottom is left bare, uncolonized by vegetation. The evaporation from bare ground exposed by the receding lake is comprised of
(1) evaporation of water rising close to the surface through capillary action,
(2) wave run-up and seiches saturate land immediately above the shoreline, and
(3) residual pools left stranded by the falling lake.

Evapotranspiration
13 KAF/yr
Vorster estimates evapotranspiration from irrigation in the basin at around 7 KAF/yr.
The remaining 6 KAF/yr is based on an assessment of three separate categories of vegetation.

First, riparian vegetation includes willows along the irrigation ditches, and pines and cottonwoods along the creeks . Their evapotranspiration is estimated based on acreage (which varies with stream flows to the lake) and the evaporation rate. Vorster believes this flow is small, only around 0.7 KAF/yr by the 1980s.

The other two categories are high elevation phreatophytes (located above 6,428 feet) and low elevation phreatophytes. The high altitude plants consist mostly of salt grass, sedge, rabbitbrush with clumps of willows around springs.

The low altitude plants are new vegetation that has been established on land around Mono Lake that has been exposed as the lake has declined from it historic high stand in the year 1919.

Ground Water Export 7.3 KAF/yr	An underground conduit transports surface water from Grant Lake through the Mono Craters and into the Owens River watershed. Vorster explains that this conduit intercepts groundwater like a "giant horizontal well." Vorster uses a constant value of 7.3 KAF/yr as a "steady state average" of this ground water flow.
Net Grant Lake Evaporation 1.3 KAF/yr	Grant Lake is a small reservoir built by the LADWP to impound the flow of Rush Creek. Vorster (1980, 68) reports the reservoir's usable capacity at around 48 KAF. If full, the lake's surface would cover 1,000 acres, but the normal area might be around 800 or 900 acres. Vorster estimates the net evaporation rate at Grant Lake to be around 20 inches/yr or 1.67 ft/yr.
Exposed Lake Bottom Evaporation 12 KAF/yr	As Mono Lake recedes from its historical high stand of 6,428 feet, much of the exposed lake bottom is left bare, uncolonized by vegetation. The evaporation from bare ground exposed by the receding lake is comprised of (1) evaporation of water rising close to the surface through capillary action, (2) wave run-up and seiches saturate land immediately above the shoreline, and (3) residual pools left stranded by the falling lake.
Evapotranspiration 13 KAF/yr	Vorster estimates evapotranspiration from irrigation in the basin at around 7 KAF/yr. The remaining 6 KAF/yr is based on an assessment of three separate categories of vegetation. First, riparian vegetation includes willows along the irrigation ditches, and pines and cottonwoods along the creeks . Their evapotranspiration is estimated based on acreage (which varies with stream flows to the lake) and the evaporation rate. Vorster believes this flow is small, only around 0.7 KAF/yr by the 1980s. The other two categories are high elevation phreatophytes (located above 6,428 feet) and low elevation phreatophytes. The high altitude plants consist mostly of salt grass, sedge, rabbitbrush with clumps of willows around springs. The low altitude plants are new vegetation that has been established on land around Mono Lake that has been exposed as the lake has declined from it historic high stand in the year 1919.