Quarterly Water Supply Strategy
and Budget Report
California American Water
Main Water Distribution
System: April – June 2020
1. Management Objectives
The Monterey Peninsula Water Management District (District) desires to maximize the long-term production potential and protect the environmental quality of the Carmel River and Seaside Groundwater Basins. In addition, the District desires to maximize the amount of water that can be diverted from the Carmel River Basin and injected into the Seaside Groundwater Basin while complying with the instream flow requirements recommended by the National Marine Fisheries Service (NMFS) to protect the Carmel River steelhead population. To accomplish these goals, a water supply strategy and budget for production within California American Water’s (CalAm’s) Main and Laguna Seca Subarea water distribution systems is reviewed quarterly to determine the optimal strategy for operations, given the current hydrologic and system conditions, and legal constraints on the sources and amounts of water to be produced.
2. Quarterly Water Supply Strategy: April - June 2020
On March 5, 2020 staff from the District, CalAm, the National Marine Fisheries Services (NMFS), State Water Resources Control Board’s Division of Water Rights (SWRCB-DWR), and the California Department of Fish and Wildlife (CDFW) met and discussed the proposed water supply strategy and related topics for upcoming quarter.
Carmel River Basin CalAm will operate its wells in the Lower Carmel Valley in a downstream to
upstream sequence,
as needed to meet customer
demand. It was recognized by the
group that WY 2020 began as if it was going to be another wet year, but the dry
February and lower than average prediction from NOAA Weather Services had
changed the water year type. The River
dropped below flow triggers for diversion of ASR and Table 13 on January 20 and
with the dry forecast additional ASR injection will likely not occur. For this quarterly water budget, it was agreed that CalAm would plan to produce water
from the wells in the
Upper Carmel Valley to support system demand will only occur
when the river is out of the “Low Flow” regime. It was assumed that the low
flow trigger would be met at some point during this quarter and without knowing
if more rainfall would push the trigger into June, the group decided to assume
the trigger would happen in May 2020.
The group will be watching streamflow and when the low flow trigger
occurs, to the maximum extent, pumping will be shifted away from the river
wells and the Seaside well field will be used to meet system demand in the
summer months. Any new sources of water reduce the water available to be pumped
from the river on a one to one basis consistent with SBO 2016-0016.
Seaside
Groundwater Basin
Because flows in the
Carmel River have fallen below values required for ASR diversions, CalAm has shut down wells in the Seaside basin to save
Native Seaside Groundwater for summer months.
Some of the Seaside wells are run during ASR diversions to maintain
pressures and meet some Seaside demand. CalAm will continue to rest the Seaside wells until the low flow trigger
occurs. At that time, the Seaside wells
will be utilized to recover Seaside Native Groundwater for this quarter of the
water year. There is a possibility the
Pure Water Monterey (PWM) will have built up the operational reserve, which is
required to occur prior to extraction of PWM water. If the requirement to build up the PWM
operational reserve is met, CalAm will begin to
recover a mixture of Seaside Native Groundwater and PWM water. There is also a goal to produce
25 AF
of treated brackish groundwater from the Sand City Desalination Plant in each of these three months.
It is recognized that, based on recent historical use, CalAm’s production from the Laguna Seca Subarea
during this period cannot be reduced to zero, as is set by
CalAm’s allocation specified in the Seaside Basin Adjudication Decision.
In
this context, the production targets represent the maximum monthly production
that should occur so that CalAm remains within its adjudicated allocation for the Laguna Seca Subarea. Under the amended Seaside Basin Decision, CalAm is allowed
to use production savings in the Coastal Subareas to offset
over-production in the Laguna
Seca Subarea. However, the quarterly budget was developed so that
CalAm would produce all native groundwater in the
Coastal Subareas and Laguna Seca production would be
over the Adjudication allotment. On
February 5, 2020 the Seaside Groundwater Basin Watermaster
Board voted to allow CalAm to claim carryover credits
to cover the pumping over the Laguna Seca allotment
in the interim prior to establishing a physical solution. Because of this decision, the Quarterly Water
Budget Group decided that the table presenting the Laguna Seca
allotment of zero would no longer be necessary as the Watermaster
is now planning to handle the pumping over allotment with a different
mechanism. The staff note from the Watermaster Board meeting is included as Exhibit 13-C.
U:\staff\Boardpacket\2020\20200316\PublicHearings\13\Item-13-Exh-B.docx