4.1 Current Potable Water Resources and Use in Loreto
SAPAL (Sistema de Agua Potable y Alcantarillado de Loretó, or the Loretó Water and Sewer System)
operates the existing municipal water system that provides service to seven communities in the
Loreto Region under the authority of Comisión Nacional del Agua (CNA). The primary water
source for the town of Loreto and a portion of the water resource for the community of Nopoló is
the San Juan Bautista Londó Aquifer depicted in Figure 1. The aquifer is located approximately 30
kilometers to the northwest of Loreto, and it is serviced by four wells operated by FONATUR that
extract groundwater and distribute it throughout these two communities. Nopoló’s water supply
is augmented by 2 deep wells that operate in an area known as the “Twins”. Water supply wells
previously operated in the Loreto groundwater basin, but were determined to be unusable
approximately 20 years ago because of contamination. For this reason, there is currently no
municipal use of groundwater from the Loreto aquifer (Quintero 2006).
SAPAL estimates that the existing distribution system wastes between 30% and 40% of its water
through normal usage due to leaks and inefficient infrastructure. Per capita, Loretanos use
approximately 513 liters/day, compared with the standard water use in Baja California Sur of 300
liters/day. Therefore the 16,000 Loreto region residents consume an amount equivalent to that
typically consumed by over 27,000 people, or 8,200 m3/day. The aquifer also serves agricultural
uses to the north of Loreto in the San Juan Londó Basin, although there are no available estimates of
the volume of this use (Quintero 2006).
4.2 Predicted Water Use in Loreto
Without significant advocacy efforts, it is not anticipated that water use patterns will change as
Loreto grows, so Loretanos’ consumption of water is not expected to significantly decrease.
Unless mitigation measures are applied to encourage conservation and upgrade existing
infrastructure, it is expected water use rates per capita will remain near where they are today.
Table 1 below shows the projected water use in the Loreto Region as determined by the
Alternative Futures Study.
 |
Table 1: Predicted Water Use in Loreto (Steinitz et al 2005, Quintero 2006)
1. The estimated water demands for the Proactivo Moderado and Proactivo Muy Regulado growth scenarios are combined
in Table 1
since their water use and population are the same. |
4.3 Challenges of Future Water Supply in Loretó
Loretó’s existing water supply would not support the per capita demands associated with the
population predictions described in the Alternative Futures Study. A hydrogeologic study prepared by
the University of Arizona in support of the Alternative Futures Study predicted that under existing
recharge conditions; the San Juan Londó Aquifer system would experience seawater intrusion
under all of the growth scenarios proposed for Loretó. Some of this intrusion is expected to occur
within the next three years under the Sin Planeación growth scenario (Maddock 2005). An additional
study released by the Sociedad de Historia Natural Niparajá (Cassassuce 2006) also predicted that demands on the aquifer
would exceed its sustainable yield in the future, although not because of seawater intrusion.
The Sociedad de Historia Natural Niparajá concluded the major risk in the aquifer is contamination by
thermal waters, containing boron and sulfate among other contaminants. This contamination is
expected to occur even if there is no additional development within the Loreto Region and
groundwater extraction continues at current rates. (Cassassuce 2006).
These recent studies of the San Juan Londó aquifer system, coupled with the projected water
demands presented in Table 1, make it clear the Loreto region will face significant water supply
challenges in the future. The existing population is currently using approximately 8,200 m3/day
and is expected to use anywhere from twice to ten times that amount within 20 years according to
the population predictions in the Alternative Futures Study. The cited groundwater analyses both
found deficiencies in the existing sustainable yield of the aquifer system, and both predict overdraft
conditions if current growth rates and water use continue. As growth continues in Loreto, the
existing water supply will simply not meet the demand. |
