Presentation on theme: "Eduardo Garaña , P.E. Director-Water Department October 15, 2003"— Presentation transcript:
1Eduardo Garaña , P.E. Director-Water Department October 15, 2003 Lake Corpus Christi/ Choke Canyon Water Rights Permit & Reservoir Operating Plan/Water Use Projections and Current Major ProjectsEduardo Garaña , P.E.Director-Water DepartmentOctober 15, 2003
2Key Dates/EventsMay City of Corpus Christi applied for Choke Canyon Water Rights.October Texas Water Rights Commission issued Choke Canyon Water Rights Permit with freshwater inflow requirements.June Choke Canyon Dam construction completed.May Choke Canyon Water Right Permit adjudicated,June Choke Canyon filled and spilled the first time.
3Key Dates/Events (Cont.) December Letter received by the TNRCC questioning freshwater inflows.May TNRCC ordered City to begin freshwater inflows to Bays and Estuaries.March TNRCC Agreed Order amended interim operational procedures and created NEAC.April TNRCC Agreed Order amends operational procedures and continues NEAC.April TNRCC Agreed Order amends operational procedures and continues NEAC.
4Choke Canyon Water Rights Permit # 3358 Special Condition 5 (b): “Following completion and filling of Choke Canyon Dam and reservoir, scheduled releases shall be made from the reservoir system at Lake Corpus Christi Dam together with return flows to the estuaries for the proper ecological environment and health of related living resources therein. …”
5Choke Canyon Water Rights Permit # 3358 Special Condition 5 (b)(cont): “...Water provided to the estuaries from the reservoir system under this paragraph shall be released in such quantities and in accordance with such operational procedures as may be ordered by the Commission. Permittees shall provide not less than 151,000 acre-feet of water per annum for the estuaries by a combination of releases and spills from the reservoir system at the Lake Corpus Christi Dam and return flows to Nueces and Corpus Christi Bays and other receiving estuaries.”
6Certificate of Adjudication No. 21-3214, 1984 - Special Condition 5.b. Requires permit holders to provide freshwater inflows to the Nueces Estuary “for the proper ecological environment and health of related living marine resources therein.”States that freshwater inflows shall:Be not less than 151,000 acre-feet annuallyBegin after Choke Canyon fills for the first timeBe in accordance with operational procedures as ordered by the Commission (now TNRCC)Be a combination of spills, releases and return flowsFederal 404 Permit includes freshwater inflow requirement.
71992 Agreed OrderAmended the 1990 Reservoir System Operational Procedures by Establishing a Monthly Schedule of Required Inflow Amounts.97,000 acft/yr. total to Nueces Bay500 acft/mo. return flow creditsCreates NEAC Whose Mission is to “Consider Such Additional Information and Related Issues and to Formulate Recommendations for the Commission’s Review and Actions.”
81995 Agreed OrderLimits amount of “releases” to amount of reservoir system inflows, up to a monthly estuary inflow targetTargets essentially the same as previous release schedule.“Pass-through” reservoir inflows up to monthly target.Reservoir inflows above monthly target are captured & stored.If reservoir inflows are less than monthly target, only inflow amount is “passed through.”No requirement to “release” stored water to make up the difference.Monthly targets reduced when salinity is in desirable range.Credits for excess pass-through’s in one month carried to next.Drought contingency provisions drastically reduce targets during low flow periods.
92001 Agreed OrderDiverts Pass-through’s and Other Inflows to Nueces DeltaNueces River Overflow Channel into Rincon Bayou.Pipeline from Calallen Pool to Rincon Bayou.Provides for Automatic Measures and Relief50%: Increased Public Awareness.40%: Restrict Time-of-Day Lawn Watering.(Inflow Targets Reduced to 1,200 af/mo)30%: Restrict Lawn Watering to No More Than Once Every 5 Days.(Inflow Targets Suspended)
10Agreed Order SummaryThe City of Corpus Christi, as Operator of the Reservoir System, shall provide not less than 151, 000 ac-ft of water per annum for the estuaries>70% storage capacity—138,000 ac-ft target>40% but less than 70%--97,000 ac-ft target>30% but less than 40%-- 1,200 ac-ft target*<30%-- Total suspension of Pass-thrus** Implementation of Lawn Watering Restrictions
11Agreed Order Summary (cont.) Additional Relief Options:>Flows in excess of monthly targets>Salinity levels in Upper Nueces BayWater Conservation and Drought Contingency Plans for Customers
12Sources of Nueces River BasinWater SupplyAUSTINLEAKEYHOUSTONDELRIOSANANTONIOUVALDEChoke CanyonDamCompleted –1982FrioRiverAtascosaRiverFrio River BasinEAGLEPASSNuecesRiverNueces River BasinWesley SealeDamCompleted –1958CORPUSCHRISTILAREDO
13Current Operating Policy Revised during drought.…..in order to provide maximum dependable yield from the two reservoirs, the water level in Lake Corpus Christi will be allowed to drop to elevation 74 feet before water is released from Choke Canyon Reservoir….. When the elevation of Choke Canyon Reservoir drops to 155 feet, Lake Corpus Christi will be lowered to its minimum elevation.
14Lake Corpus Christi Reservoir Wholesale Water Providers BeevillePipeline1982Lake Corpus Christi ReservoirWholesale Water ProvidersMathisPipeline1982AlicePipeline1964
15Choke Canyon / Lake Corpus Christi Reservoir System Daily Pass-Through Status Report Report Date: May 28, 2002RESERVOIR STATISTICS
25Background (cont.)Water provided to the estuaries from the reservoir system under this paragraph shall be released in such quantities and in accordance with such operational procedures as may be ordered by the Commission. Permittees shall provide not less than 151,000 acre-feet of water per annum for the estuaries by a combination of releases and spills from the reservoir system at the Lake Corpus Christi Dam and return flows to Nueces and Corpus Christi Bays and other receiving estuaries.
26Background (cont.) Construction Completed 1982 Inundation Occurred 1987Letter of Inquiry Received 1989Texas Water Commission Took Jurisdiction in Spring 1990Creation of Technical Advisory CommitteeTAC—Characterization Study and Final Report to Hearings Examiner
27Water Use Projections for Corpus Christi Regional Water System SalutationIntroduce Panel MembersDemand (Sources and Methodologies)Supply Definitions and Current SupplyCurrent Demand and Supply
29Projection Comparison City and TWDB SupplyRegional Water PlanOne-period growth rate equation (High-Case)Linear Regression Method (Low-Case)These are different ways of estimating use. Difference here is the use of open ended contracts for wholesalers and untreated water customers. Contracts call for their maximum use to be the highest three yr. average + 10 percent.Regional Plan identified about 10K AF of needs from cities that would not be able to meet the new stricter arsenic standard and could possibly be looking our way to meet that need.We feel we capture that with our 8 percent planning margin which equals 10K AFacre-feet
32Reservoir System Yield That amount of water that the reservoir (or reservoir system) could have produced annually if it had been in place during the worst drought of record.That volume of water you can reliably depend on each year during the worst drought or drought of record.The Drought of Record is the dry period between times like now when the reservoirs are at full capacity (approximately 84 months).
33Reservoir System Inflows- Lowest 3 Year Periods Each drought is getting more severe as measured by the lowest 3 year periods of inflow in each droughtDroughts of the 50’s, 60’s, 80’s, and 90’s.We live in an area dominated by worsening drought and punctuated by short wet periods.acre-feet
34Reservoir System Yield Modeling Assumptions Safe yield assumption-reservoir is left with a volume of reserve supply (6 months of supply)Firm yield assumption-reservoir is used till emptySafe yield assumptions could be 4 month reserve or 12 mo or 10 percent of reservoir capacity.For the purposes of planning our water resource needs ( a basic necessity) we are applying both a firm yield and safe yield when considering supply in the reservoir systemWe can’t assume for planning purposes, that all of the volume in a reservoir is usable, or that we could use all of the reservoir volume till empty.We don’t think it’s reasonable to assume that during a drought of record the reservoir would be used till empty.Drought periods are getting more severe over time, this is an area dominated by drought with occasional wet periods.It becomes a question of quality.You may not run out completely (and this is true for many natural resources) at some point it becomes too expensive to treat and use.
35Firm Yield CCR/LCC System (1992 – 2001) 300,000250,000Captures the variability of firm yield calculation. It can change due to a number of reasons. For example...1992 (HDR)Phase II CCR/LCC System Operations Policy1992 Interim OrderHDR/TNRCC Hydrology (1934 – 1989)1995 (HDR)1995 Agreed Order (the pass through plan)1997 (HDR)Phase IV CCR/LCC System Operations Policy lower LCC and less evap and more opportunity to capture1995 Agreed Order1998 (HDR)Phase IV CCR/LCC System Operations PolicyHDR/TNRCC Hydrology (1934 – 1997)2001 (HDR)2001 Agreed Order200,000System Yield (acft/yr)150,000100,00050,00019921995199719982001Time (Non-Successive Years)
36} } Total Supply (2003) Firm Yield Safe Yield 237,000 202,932 Texana Two Bar Graphs Compare differences between FY and SYSeen on the bottom shaded portions of each.For FY 183,160For SY 149,069The other shaded portions are the same for both cases…31,400 Firm Texana water purchased and delivered through the Mary Rhodes Pipeline.10,400 also delivered through MR Pipeline is temporary in that it allows for growth in Jackson County4,500 acre-feet was recently purchased interruptible waterAnd our totals supply is shownunder FY 229,500 AFunder SY 195,432 AFWhat do each of these look like over time?TexanaCCR / LCCCCR / LCCacre-feet
37Total Supply Projection (Current Sources) These are the two different levels seen on the previous graphThe decrease over time due to sedimentation of the reservoirs.acre-feet
38Demand and Supply acre-feet Finally we examined where demand overcomes supplyIt depends on whether you’re looking at a firm yield assumption or a more realistic safe yield assumption.When we compare the Demands using the 1PGR and LR to the Firm Yield Result:Demand overcomes supply as early as 2036Demand overcomes supply as late as 2048Under Safe Yield MethodologyDemand overcomes supply as early as 2025Demand overcomes supply as late as 2030We end up with this polygon or quadrangle or quadrilateral shaped area that represent our worst and best case water resource scenarios.acre-feet
41Summary Demand = Supply 2028Safe Yield/ Higher Demand2034Safe Yield/ Lower Demand2038Firm Yield/ Higher Demand2052Firm Yield/ Lower DemandSlideIncreased future economic opportunity is only one cost of not meeting your needs.The costs of not meeting your needs are tremendous.The costs of not meeting a city’s water resource needs far outweigh the capital costs to meet needs.
42Future Actions Continue to use multiple projection methodologies Compare city’s projections to TWDB’s and other available projectionsContinue to update projections on a one-year planning cycleOptimize existing water supply sourcesContinue to develop future water supply sourcesSlideIncreased future economic opportunity is only one cost of not meeting your needs.The costs of not meeting your needs are tremendous.The costs of not meeting a city’s water resource needs far outweigh the capital costs to meet needs.
45Preferred Facility Siting Preferred RO Facility:Padre Island Pump Station / Nueces County Packery Channel ParkAlternate RO Facility Location:At NCWCID4 Pumping StationAlternate ASR Well Location:Mid-Mustang IslandPreferred Source Well Location:City-Leased TGLO Land at Packery ChannelPreferred ASR Well Location:Near Nueces County Padre Balli Park along South Padre Island Drive
46Recommended Project 3.0-mgd project includes: Chicot Aquifer Horizontal Directionally-Drilled well field1.0-mgd RO facility(with buildings and infrastructure to support 5-mgd)2.0-mgd ASR capacityBy-Product Disposal via Deep Well Injection(with sufficient capacity to handle 5.0 mgd)Site work and transmission pipingUpgrades to existing Padre Island Pumping StationEstimated cost: $23.2 million including contingencies (June dollars, 30 percent)Subject to verification/refinement based on results of hydrogeologic and water quality testing program
48Why Coastal Bend? Why Corpus Christi? Largest Gulf-front City with a Strategic Port in TexasLargest Industrial City in Attainment Status for Air QualityProgressive and History of Long-range Water PlanningMary Rhodes PipelineWater demands met through 2050Regional Water SystemProximity to UsersLocal and Regional Support
49City of Corpus Christi Regional Water System City of Corpus Christi and Coastal BendServes 75% of M&I Demand for Region NSupply Water to Suppliers in Seven CountiesExisting Municipal CustomersExisting Industrial CustomersKoch/Flint Hills, Citgo, Valero, Coastal, EquistarPower GenerationPotential to Supply Future Customers
51Texas Coastal Bend Project Description 25 mgd seawater desalination facilityLocated at Barney Davis Power PlantDeliver potable water to Corpus Christi Regional Water SystemAbility to ExpandExisting Marine R&D facilitiesHart FoundationA&MUTMSI
52Barney Davis Plant Site and Corpus Christi Distribution System A&M /UTMSI ExistngMarine Research FacilitiesA&M /UTMSI ExistingMarine Research FacilitiesOso Bay
55US Army Corps of Engineers Reconnaissance Study of the Nueces Basin Watershed Federal funds are available through Corps of Engineers (COE) for projects which include “Ecosystem Restoration” or “Flood Damage Reduction”Federal funds can pay for up to 50% of study cost and 65% of construction costsProjects can include water supply
56Important Ecosystems Dependant on Nueces River System Hill Country Streams and Associated SpringsNueces Delta and Estuary15
57US Army Corps of Engineers Reconnaissance Study Identified 10 Projects Flooding downstream of Lake Corpus Christi and throughout the Nueces BasinRecharge enhancementCotulla diversion projects to enhance storage in LCC/CCR systemTwo-way pipe project to enhance storage in LCC/CCR systemDesalinationTreated effluent placement in Nueces DeltaWater quality in Choke Canyon reservoirStream restoration in the upper Nueces BasinBrush managementExotic aquatic plant removal
58Projects Selected to Move Forward to Feasibility Phase Desalination -Locally and regionally supported concept. Originally studied in the Coastal Bend Regional Water Plan is sited next to an existing power plant to minimize power costs and reduce treatment costs utilizing heat from the plant. Also combines brackish groundwater with seawater to reduce concentration of TDS in brine, through existing plant discharge facilities.Cotulla diversion -Water quality enhancement, water supply and possible flood damage reduction project bypasses high channel losses in the braided reach and increases storage capacity.Two-way pipeline -Conveys releases over 33cfs with very little losses, creates opportunity for more freshwater inflow by increasing reservoir storage. Higher lake levels improve water quality. Development of off-channel storage site with a pump station would provide flood control benefits to the Nueces delta and could increase firm yield to regional suppliers with less evaporation loss.Wastewater diversions -Take treated effluent from one or more of the City’s municipal wastewater treatment plants and discharges it into critical areas of the delta to help restore the balance of freshwater and nutrients, studies show a potential increase in biological productivity of 3 to 5 times.Recharge enhancement projects -Would contribute significantly to the spring flow, reduce the possibility of the springs going dry, protecting the ecosystem. Would require mitigation to the City. A portion would be used for water supply.Brush control -would use plowing, grubbing and dozing as well as herbicides and controlled burns to control the dominance of trees and brush, resulting in increased stream flow and aquifer recharge.Desalination project at Barney DavisCotulla diversion to enhance Choke Canyon storageTwo-way pipe project between CCR and LCC to minimize channel lossesAdditional wastewater diversions to Nueces River DeltaRecharge enhancement projects with appropriate mitigation for CityBrush control
59Study Participants Co-sponsors Army Corps of Engineers City of Corpus ChristiSan Antonio Water System (SAWS)San Antonio River Authority (SARA)Guadalupe Blanco River Authority (GBRA)Nueces River Authority (NRA)Other Interested PartiesEdwards Aquifer Authority (EAA)Region N Water Planning Group (Region N)
60City Permitting Requirements, Time and Effort Planned Padre Island DesalinationPermits for hydro-geologic borings and permit validation studiesAllowance of $1M, 100 percent City ExpenseTwo Desalination Projects at Barney DavisExpected to benefit from TWDB’s RW Beck ReportSouth-most Brackish, Freeport, Padre Island Experience will be used
61Permitting Requirements City Time and Effort Planned Cont. Additional Wastewater Diversions to the Nueces DeltaCity has expended extensive time and resources to investigate and establish baseline information for use in possible expansion wastewater diversion projects.