HomeMy WebLinkAboutMinutes Water Resources Advisory Committee - 06/15/2016 Minutes of Water Resources Advisory Committee
held 11:30 a.m. Wednesday June 15, 2016
( Water Utilities Building Choke Canyon Conference Room
2726 Holly Road* Corpus Christi, Texas
Attended by:
Voting members: Sally Gill, Landscaping; Sam Sanders, Large Commercial Customer; Rocky
Freund, Nueces River Representative; Brian Williams, Wholesale; Joelle Francois, Residential
Representative;Phil E. Hale, Apartment Representative; Roberto Reece, Military Representative.
Ex-officio Members: None.
Staff: Bill Green, Gabriela Morrow and Itzel Ojeda of City Environmental & Strategic Initiatives;
minutes taken by Itzel Ojeda and compiled by Bill Green
Guests: Susan Butler and Pete Anaya, CH2M Engineering.
ITEM 1: Call the Meetinq to Order
Chairman Sam Sanders called the meeting to order at 11:30 a.m. with a quorum of seven
members attending.
ITEM 2: Review and Approval of Minutes
The minutes from the Thursday May 12, 2016 meeting were unanimously approved.
ITEM 3: Update on Drought Contingency Planning and Water Supply Index
Mr. Bill Green began with the Drought Planning review of the combined Reservoir Capacity, which
is 45%. Combined capacity increased 1% from last meeting. Lake Texana is at 100% capacity.
Choke Canyon is at 34% and Lake Corpus Christi is slightly below 75% of its full capacity.
Bill presented the Conservation Watch slide showing the Drought Impact on Texas Surface. He
went over the models used for Water Resource Planning such as Drought triggers, Near-term
projections and Long-term planning and operations. Bill informed the group that HDR is
presenting a Water Supply Model to the City and it may be updated by Fall.
The Water Supply Combined Daily Water System Index is 48.8% as of June 7, 2016.
Bill Green introduced Susan Butler and Peter Anaya with CH2M to the group. Susan started her
presentation explaining to the group the bridge between the Water Supply Index and how the City
manages its resources and communicates the information; this bridge is the Texas Drought Index
Study by Texas A&M. The objectives of this study are:
Examine current/available drought monitoring and prediction tools
Evaluate the tools to determine which are most appropriate for monitoring moisture levels
at the local level in Texas
Develop operational definitions for droughts to identify onset and duration
Develop guidelines for reporting of drought conditions
Make recommendations on how this information can most effectively be implemented by
the user
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Susan explained the group the two kinds of drought:
Meteorological drought: shortage of precipitation/moisture supply over some period of
time
Hydrological/water supply drought: an extended period of time of below normal
precipitation that results in deficiencies in streamflow, groundwater, and lake and
reservoir levels.
The hydrological/Water Supply Indices investigated by this study are:
Standardized Precipitation Index (SPI)
Palmer Hydrological Drought Index (PHDI)
Surface Water Supply Index (SWSI)
Percent of Reservoir Storage Capacity
Streamflow Percent Exceedance
Standardized Streamflow Index (SSFI)
Streamflow Deficit Index (SDI)
Standardized Reservoir Index (SRI)
Reservoir Deficit Index (RDI)
Susan went over the quantitative and qualitative evaluation of the study.
Susan explained to the group the Standardized Precipitation Index (SPI). It is produced by
standardizing the probability of observed precipitation for any duration. It is usually calculated
with a Pearson Type II or Gamma probability distribution. It requires specialized software,
distributed by National Agricultural Decision Support System. Susan went over advantages and
disadvantages of the Standardized Precipitation Index (SPI).
Susan showed the group the Reservoir Deficit Index (RDI) formula.
Ratio of the difference of the current reservoir level and the median reservoir level
RDI= (wl-Mwl)
Mwl*100
wl = current reservoir water level
Mwl = long-term monthly median water level from WRAP simulation
Inputs required: historical weather and streamflow data for WRAP simulation
She went through the advantages and disadvantages of the Reservoir Deficit Index (RDI).
The Findings are:
RDI (or SPI) - compares current conditions to past trends at time scales that incorporate
rainfall patterns and storage effects
Reliability Index Spreadsheet - gives projections and can be used as an
operations/management tool; can be combined with RDI with minor modifications
Susan closed her presentation with the following recommendations:
Perform test analysis of SPI and RDI to validate calculation ease, data availability and
performance
Assess correlation to current and proposed modified WSI and historic known drought
periods
Update toolset (WSI and Water Reliability Index)
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Sally Gill asked how is this going to be presented to the public, is it going to be presented by
percentages 0 to 100? Susan answered it is recommended to be tied into the Drought
Management Plan and any future revisions. Sally suggested that it would be easier to the public
to be presented in percentages since they are used to them. It would be easier to explain to
people that before we were looking at the capacity of Lake Corpus Christi and Choke Canyon
Dam and now we are adding Lake Texana and Lake Colorado, once it gets down to the
community, percentages would work. Bill Green agreed it is an opportunity to re-visit our Drought
Index Plan and there are some opportunities to be considered. They group agreed it is important
to pay attention to evaporation. Rocky Freund suggested the City may consider the need to use
both indexes for a while.
Mr. Reece questioned how changing what the City have in place right now is going to make a big
difference to the community. He explained Federal government implemented some programs for
several buildings to reduce their energy use, and that he wanted to let the public know how great
they were doing. His concern is, if the City starts throwing the numbers out there it will confuse
the public; and how is the City going to integrate this new system with the current one. Sally Gill
suggested to leave the numbers as they are and have a second methodology to go along with it.
Bill answered this is part of what the City is looking at in terms of drought response. The City
needs to make sure the message is clear and understood.
ITEM 4: Review and Discussion of Day of Choice, Weekly Watering Outreach
Bill Green presented to the group Day of Choice, Weekly Watering Outreach flier put together by
Gaby Morrow PIO with the City. He informed that Communications Director thought it was a great
idea and will publish it in the City webpage. Sally thought the flier was great. Bill explained the
residents are allowed to choose random days as long as they water once a week before 10:00
am and after 6:00 pm. Sally suggested it could be added "Encouraging Healthy Plant Growth."
The message should be: Water once a Week if needed according to rainfall. The group agreed
to specify "no more than once a week." Gaby Morrow will make the suggested changes and will
send the flier to the members.
ITEM 5: Proposed Water Aquifer Storage & Recovery Feasibility Presentation
Bill Green presented the study HDR is doing for Aquifer Storage Recovery for the City of Corpus
Christi. The goal is to provide additional supply that is economical, efficiently integrate in existing
system, and enhance water supply reliably. In 2005, the Corpus Christi Aquifer Storage and
Recovery Conservation District(District)was established to manage and protect the groundwater
resources within the City limits (District service area).
This study is important to:
Promote regional water supply diversification
Evaluate regional water supply cost-effectiveness
Enhance water system operational efficiency
Conserve and repurpose the City's existing water resources
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The 2016 Region N plan identifies up to 18 MGD through consolidation and regionalization of
WWTP that could be available for aquifer storage
The scope of this Study includes:
Formulation of program
Exploratory test drilling program
Geochemical analysis
Field scale groundwater availability model
ASR operating policy considerations; and
A technical report of findings to the City and the TWDB
ITEM 7: Rain Barrel Sale Update
1,117 Rain Barrels distributed
Fall 2016 Event Planning
Community Service Certificate
ITEM 7: Set next meeting date
The next meeting was scheduled for 11:30 AM Wednesday September 15, 2016.
ITEM 8: Admiourn
Mr. Sanders adjourned the meeting at 1:16 pm.
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