Ing. Adriana RodriguezSubdirección General Técnica
Gerencia de Ingeniería y Normas Técnicas
Salinity and Desalination in Baja California: Challenges and Solutions
Water Resources Research Center 2011 Annual Conference
Yuma, Arizona, April 26, 2001
Establishes that:
• “Of the Colorado River waters,whatever their source, thereare assigned to Mexico aguaranteed volume of 1850.2Mm3 per year”.
• In cases of extraordinarydrought or serious accident tothe irrigation systems in theUSA, this volume is reduced inthe same proportion ofreductions in the U.S.
International Treaty of 1944: Delivers to Mexico
• When the water in the Colorado River is in excess of the needs ofsupply / consumption in the U.S., they are obligated to deliver toMexico additional volumes of water from the Colorado River Systemfor up to a total volume not exceeding 2096.9 Mm3.
Issue
• From the 1,850 Mm3 that USA deliver to Mexico, 172.7 Mm3
are delivered at Southern International Border (SIB) throughSanchez Mejorada Canal, and this water has high salt content
Attention provided
• To ensure that water that Mexico receives at SIB can be used,in 1997 a Binational Technical Group was formed.
• Within this group the options to improve the water quality atSIB were discussed.
• In March 1999, USA proposed to Mexico options in short,medium and long term to improve water quality at SIB
• From 1999 to 2000 surplus in the Colorado River Basin wereused and annual volumes up to 2,096.931 Mm3 were allocated
Quality of water delivered by USA to Mexico
• In 2002, USA installed devices for better regulation of thewater delivered to Mexico at SIB.
• The construction of the interconnecting canal to divert waterfrom Yuma’s agricultural drainage to Wellton-Mohawkdrainage during critical months (October to January), anddilute the water from the drainage with water from wells tomaintain salinity levels of 1,200 ppm at SIB.
The project was conducted in three phases: Construction of a branching structure and Wellton
Mohawk diversion canal. Installation of variable speed pumps and electronic
systems. Automated Control Center to operate the entire system.
Attention Provided
• The three phases were finished in 2007.• At a cost of 1.8 MDD the control center was concluded to
operate pumps and valves.• In 2007, at a cost of 6MDD, the system of water
management in the area of Yuma, Az., was finished, amongother benefits allows the USBR automate some operationsof the system at SIB.
• In the critical months (October – January) the systemoperates and the goal is to deliver water to Mexico with1,200 ppm daily average.
• To achieve this, 8,000 acres-feet of water are used to dilutethe water and comply with salinity.
Current Status
• Although the actions allow an average salinity of1,200 ppm.
• Mexico remains its position before USA on the waterthat should be receiving must have the adequatequality all time to ensure its beneficial use.
• Both governments should continue exploring actionsto achieve a better quality of the water delivered toMexico from Colorado River.
• Formalize these actions and those necessary toensure that Mexico keeps receiving water tobeneficial use, through the signing of a joint report ofprincipal engineers from IBWC.
Next Steps
The low rainfall in Tijuana, Rosaritoand Tecate, B.C., is a difficulty tosatisfy the increasing demands ofdrinking water.
That is why the search of securesources and the water supply to coverthe basic needs of the populationhave been a constant challenge.
Currently, local sources are used andwater is imported from Colorado Riverthrough Colorado River-TijuanaAqueduct.
Background
Ensenada
Tijuana/Rosarito Mexicali
San LuisRío Colorado
Presa DerivadoraJosé M. Morelos
Tecate
Mesa Arenosa( 63 Pozos )
Canal Alimentadordel AcueductoAcueducto
Río Colorado - Tijuana
Water Sources
• Overexploitation of aquifers leading to a notable decrease inthe amount of available water, saline intrusion, desertificationand deterioration of aquatic systems.
• Contamination of groundwater by discharges mainly urban,industrial, agricultural and mining that cause poor waterquality, eutrophication and deterioration of aquatic systems
• Changing land use for agriculture, forestry and urban andindustrial growth, through activities that change theenvironment such as deforestation, basins alteration,modification of natural vegetation, soil loss, engineering,pollution and fires.
• Introduction of exotic species to water bodies and thesubsequent displacement of native species and decreasingbiodiversity
Water Problems in Baja California
Source: Programa Hídrico Visión 2030 del Organismo de Cuenca Península de Baja California
• Of the total groundwater available in the Region, 60% is locatedin the Mexicali Valley and the “Mesa Arenosa”, San Luis RíoColorado, the first one for agricultural use and the second oneto supply water to border cities from San Luis Rio Colorado toTijuana.
• However, irrigation efficiency is very low and there is a hugewaste of water due among other causes, to rudimentaryirrigation practices, poor maintenance of water infrastructure,leveling problems and inadequate water management at farmlevel.
• Water losses by seepage in unlined canals with capacity up to 1m3/s are 17 l/s/km and in canals with more capacity are 23l/s/km. At farm level, efficiency is 71%, resulting in a totalefficiency of 56% in the gravity conduction systems, whichmeans that for every cubic meter diverted, almost half of wateris lost.
Water Problems…
The Colorado River meets much of the water needs of seven states in theUSA, two from Mexico and thirty-four American tribes. This represents apopulation of 30 million people, projected to reach 38 million by 2020. Inthe past 100 years, the total percentage of area affected by extremedroughts, in the U.S. has ranged from 14% a year on average, with amaximum of 65% in 1934.
It is well documented that the allocation of Colorado River water to thebasin States took place during the wettest period (between 1905 and1925), in a period of 400 years.
Recently, the western U.S. has suffered a sustained drought, 30-40% ofthe region is subjected to a severe drought since 1999, and the ColoradoRiver has had, between 2000 and 2004, the five-year low flow rate everrecorded. In addition, States of the southwestern U.S. are experiencingone of the fastest growth rates in the country and generate a socialdemand, economic and environmental resources, with the resulting legaldisputes.
A small portion of the Colorado River basin (15%) provides most of itsvolume (85%). Estimates show that with global warming and increasedevaporation, runoff reduction reached 30% during the twenty-first century.
Under these conditions, and taking into account the planned withdrawals, itcould only meet the needs specified in the Colorado River Compact for 60-75% of the time between now and 2025.
Some studies estimate that by 2050, average moisture conditions in thesouthwestern U.S. could match those seen in the 50s, such changes would bedue to rising temperatures.
Most scenarios of Colorado River flow at Lees Ferry indicate that, in 20 years,the runoff could be insufficient to meet current demand of water resources.
Recent experience suggests that conditions are now 'critical' in that basin.The variability and climate change, coupled with increasing pressure becauseof the effect of development, will cause unprecedented scale droughtsunknown for the institutions of the region and exacerbate conflicts amongwater users.
Source: El cambio climático y el agua. Documento Técnico VI del Grupo Intergubernamental de Expertos sobre Cambio Climático
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US-Mexico Cooperation ActionsWith the vision of managing the watershed integrally, within the IBWC it wasformed in 2008 a core group and four working groups with representatives offederal, state and NGOs in Mexico and the US.
Main Objectives of Mexico
• Meet current water needs, and future for urban uses, agriculture andenvironment in the US-Mexico border
• Assess current weather conditions, and future condition of scarcity.• Developing new sources and increase storage capacity.• Binational investment programs for water conservation and environmental
improvement.
Main Objectives of the US
• Addressing current needs of water quantity and quality and in the futureurban use, agriculture and environment of US and Mexico
• Implement procedures to better manage water scarcity.• Evaluate potential water exchange US-Mexico of new sources produced by
the development of infrastructure, improvements or other projects.• Assess potential impact of climate change on Colorado River.
Identified Projects in the Working Groups
• Lining of 75 Km from the ID014 main network, with anapproximate cost of 680 MDP, with this project about 46hm3/year will be recovered. This volume is notcompromised.
• Identification of sites to construct desalinationplants at Rosarito and Puerto Peñasco.
• Establishment of five priority areas of conservation andmap of water needs for the environment, considering theboundary sector, riparian and Colorado River Delta.
• Aquifer monitoring, shortage and drought plans, annualand multiannual storage in Mexico and USA, modelingthe whole Colorado River System, operational storage.
Importance of Desalination
Desalination is an alternative of solution because istechnically and economically feasible.
• In 2002 there were 171 desalination plants– Installed capacity 781 l/s
• In 2006 there were 435 registered desalination plants– Installed capacity 3,600 l/s– This represents 5 times more.
The main process in Mexico is reverse osmosis with 76% of the plants
From the total capacity, 45% is for seawater and 42% for brackish water
The State with more desalination plants is Quintana Roo with 79 plants, followed by Baja California Sur with 71.
64% of the deslination plant are privately owned, mainly for tourism
The desalination plant in Los Cabos is the first one in Mexico to supplydrinking water to a community of 40 thousand inhabitants, which hasmade desalination in Mexico to be an option for reducing the lack of waterto supply basic needs of the population.
Source: Comisión Nacional del Agua. Octubre 2009
In 2006, the biggest municipal Desalination Plant began to operate in Los Cabos, South Baja California, with a
Capacity of 200 l/s
Rosarito Desalination Plant
Desalination PlantEnsenada
PowerPlantSouth Bay
Ground of IBWC
Mexico
USA
Rosarito, B.C.• Capacity 2,190 l/s; 1,195 in the first
stage, (it is estimated a requiredinvestment of 1,300 MDP, it is expectedthe participation of USA in itsconstruction).
La Misión, B.C.• Capacity 250 l/s, the basic engineering
study is been conducted. It is expectedto supply the urban zone located northof Ensenada and the south of Playas deRosarito.
Ensenada, B.C.• Capacity 250 l/s, in bidding, it is
expected to begin its constructionsshortly with a period of 18 months.
Puerto Peñasco, Son.• Capacity in a first stage 4,700 l/s. It is an
initiative of the State of Arizona, it isexpected that the water would be usedfor municipal and agricultural uses.
Desalination PlantLa Mision
Binational Desalination Plant in Rosarito, B.C.It is under analysis to build a Binational Desalination Plant in Playas deRosarito, BC, with a capacity of 1,095 l/s at an initial stage to 2.190 l/sas final capacity.
The volume of desalinated water would be shared between Mexicoand the United States.
Currently, San Diego County Water Authority is financing the FeasibilityStudy and the Preliminary Design of the Plant .
The activities in which we work are:
• Data collection• Field visits to possible sites for the plant• Tour through various routes for water delivery• Energy requirements• Water demand projections for Mexico and the US• Requirements and Environmental Permitting
Conclusions of the first stage
Potential Sites to construct the plant
Corridor 2000
Rosarito BeachDesalination Site
Inland RouteCoastal Route
Potential routes to convey product water
• The project is feasible.
• The water demand of Mexico and USAis higher than expected, even higherthan 2,190 l/s.
• There are potential sites to constructthe Plant.
• There is enough energy available tothe Plant. CFE would allow the use ofits intake and its discharge for brinedisposal.
• It is required to develop morealternatives to convey product water.
• Complicated EnvironmentalPermitting.
Next Steps
• The scope of work of the project is being revised tobetter define the objectives of it.
• It is expected to develop the necessary information todecide whether to continue the project or not.
• Additional partners are being sought to fund the project.
• We continue working within the Joint CooperationProcess.
For CONAGUA, the project is very important, in 2011, hasscheduled 250,000 dollars to:
Through IBWC support the development of thesecond phase.
Analyze the effects of the desalination project inTijuana, B.C. - San Diego Ca region.
Because of the pressure that theimplementation of desalinationprocesses will involve in ourcountry, due the scarcity offreshwater, is crucial, to haveclear rules, both handling andmanagement of the facilities andthe quality to be met by theproducts and waste products ofthe same, with the goal to complytwo basic objectives, increase thewater supply and notcontaminate.
Challenges: Legal Framework
• The LAN defines concession as the title given by CONAGUA forexploitation, operation and use of the national waters, andtheir inherent public assets, to individuals or legal entities ofpublic and private, except allocation titles. (Art. 15 Fracc. III)
• And states that grant is not required for the extraction ofmarine internal waters and territorial sea, for exploitation oruse, except those that are intended to desalination, which willbe awarded. (Art. 17).
• It also states that the public works necessaries, that allow tosupply, treatment and desalination, whose implementationaffects two or more states, are federal competence throughCONAGUA. (Art. 96 BIS 2, Fracc. IV)
Proposal• Draft NOM-000-CNA-0000, Drinking Water – that will establish the
specifications to be met by desalination plants of seawater andbrackish water for human use.
Objective• To establish the specifications to be met by desalinations
facilities of seawater, brackish water for human use, andwastewater discharges.
Application Field• The specifications will be mandatory for all public and private
facilities, whose purpose is the desalination of seawater or brackishwater, whatever the procedure use for this purpose; are alsosubject, water resources thus obtain, which are integrated – in thecase of seawater desalination – to the hydrological cycle, togetherwith freshwater, and renewable groundwater.
• The use of techniques for obtaining non-renewable resourcessuch as water desalination should be considered afterconsidering all possible ways to save on all water-consumingsectors.
• The quality of water obtained by the desalination methods issuitable for any human consumption, supply and agriculturalirrigation..
• Only some very specific industrial processes require specialtreatments.
• At present, desalination is in some countries one of their mainsources of water with a large number of desalination plantswith a fully satisfactory performance.
• In Mexico, the most used process for water desalination isreverse osmosis, with 76% of the plants according theinventory, and most of them are running for the hotel industry
• The desalination plant in Los Cabos is the first one in Mexico tosupply drinking water to a community of 40 thousandinhabitants, which has made desalination in Mexico to be anoption for reducing the lack of water to supply basic needs ofthe population.
• It is expected that in the medium term, desalination is also anoption to apply to different uses of human consumption, suchas agricultural irrigation of crops with high commercial value.
• Should not be denied the environmental impact associatedwith desalination plants, the most important are brinedischarge, the chemicals used and the CO2 and NOx generationcaused by energy consumption.
• Before it, and finally, proper legislation can minimize theseimpacts, as opposed to the environmental impact of apermanent nature, derived from these large hydraulic works.
However progress will be necessary to continue working on theactions that allow:
• Generate new sources of water that would increase watersupply and reduce pressure on the hydrological system.
• Explore US investment schemes in infrastructure in exchangeof water by specific time, which are of interest and benefit forboth countries.
• Solve technical, legal, economic, environmental, social,political issues associated with the project.
• Review and approve jointly cooperation projects in theframework of the IBWC.
• Involved all affected (federal, state, users, legislators, amongothers)
Next Steps
Final MessageThe Governments of Mexico and the US have been characterized by:
The great capability of jointly provide efforts to strengthen policiesto protect the environment and natural resources sustainably;
The willingness to cooperate in the search for joint actions toimprove environmental quality and optimize the quality of life ofpeople in the border region shared by both countries.
Opportunities for collaboration and the importance of strengtheningcooperation through initiatives on priority issues of commoninterest.
The willingness to promote new mechanisms for dialogue andagreements leading to the strengthening their relations of friendshipand mutual productive action;
The desire of the National Water Commission is that the binationalcollaborative effort, is considered as an international example globally, interms of integrated water management by basin.
Water Resources Research Center 2011 Annual Conference
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