HR: 1400h
AN: H33C-03 [Abstracts]
TI: Evaluating Water Supply and Water Quality Management Options for Las Vegas Valley
AU: * Ahmad, S
EM: sajjad.ahmad@unlv.edu
AF: University of Nevada, Las Vegas, 4505 Maryland Parkway, Las Vegas, NV 891544015,
United States
AB:
The ever increasing population in Las Vegas is generating huge demand for water supply on one hand and need
for infrastructure to collect and treat the wastewater on the other hand. Current plans to address water demand
include importing water from Muddy and Virgin Rivers and northern counties, desalination of seawater with trade-
payoff in California, water banking in Arizona and California, and more intense water conservation efforts in the
Las Vegas Valley (LVV). Water and wastewater in the LVV are intrinsically related because treated wastewater
effluent is returned back to Lake Mead, the drinking water source for the Valley, to get a return credit thereby
augmenting Nevada's water allocation from the Colorado River. The return of treated wastewater however, is a
major contributor of nutrients and other yet unregulated pollutants to Lake Mead.
Parameters that influence the quantity of water include growth of permanent and transient population (i.e.,
tourists), indoor and outdoor water use, wastewater generation, wastewater reuse, water conservation, and return
flow credits. The water quality of Lake Mead and the Colorado River is affected by the level of treatment of
wastewater, urban runoff, groundwater seepage, and a few industrial inputs. We developed an integrated
simulation model, using system dynamics modeling approach, to account for both water quantity and quality in
the LVV. The model captures the interrelationships among many variables that influence both, water quantity and
water quality. The model provides a valuable tool for understanding past, present and future pathways of water
and its constituents in the LVV.
The model is calibrated and validated using the available data on water quantity (flows at water and wastewater
treatment facilities and return water credit flow rates) and water quality parameters (TDS and phosphorus
concentrations). We used the model to explore important questions:
a)What would be the effect of the water transported from the northern counties on the water supply and water
quality of Lake Mead?
b)What would be the impact of increased reuse of wastewater on return credits?
c)What would be the effect of treating runoff water on the load of nutrients to Lake Mead?
DE: 0496 Water quality
DE: 0545 Modeling (4255)
DE: 1871 Surface water quality
DE: 1884 Water supply
DE: 6344 System operation and management
SC: Hydrology [H]
MN: 2007 Joint Assembly