Water allocation in transboundary basins Status and good practices

Integrating flexibility and hydrological changing conditions into an agreement: The case of Albufeira Convention (-)

Pedro Serra

Geneva, October, 16th-17th 2017 Introduction

Portugal is an independent Nation since 1147, at a time when in the coexisted many kingdoms that afterwards would give place to the Kingdom of Spain. The borders between the two countries were defined in 1298 and they are the oldest in Europe, eventually in the whole World. Introduction

Pluviometria and geography are advantageous to Portugal. The Northern part of the Peninsula is humid, whilst the Southern part is dry, specially in Spain.

Tajo’s river basin makes the transition from the humid Iberia to the dry one, in Spain as well as in Portugal. The 1927 Convention on the

Transboundary cooperation really started in 1927, when a Convention on the sharing of the hydropower potential of the border stretch of this river was signed and a Portuguese-Spanish Commission in charge of management was set up. This convention was updated in 1964. The 1968 Convention on the Minho, Lima, Tajo and rivers

Another Convention was signed in 1968 with the scope of sharing the hydraulic potential, and no longer the hydropower potential, of the border stretches of the other transboundary rivers. Spain wanted to build the Tajo-Segura Aqueduct, to bring water to the Southern part of the territory, and Portugal wanted to build the Alqueva Dam, for irrigation purposes in the . The 1968 Convention on the Minho, Lima, Tajo and Guadiana rivers

Aqueduct Tajo-Segura Up to 1000 million m3 may be transfered each year (30 m3/sec) to be used in the Segura river basin. The 1968 Convention on the Minho, Lima, Tajo and Guadiana rivers

Alentejo’s Irrigation Plan In Portugal the irrigation of 200.000 ha in Alentejo, in the Tajo, Guadiana and Sado river basins, was foreseen. Dam builders

By the end of the 1980ies the situation in the main transboundary rivers presented itself as follows: . Dozens of dams had been built, both in Spain and Portugal; . Because of agricultural and industrial development, waters were highly polluted almost everywhere; . Water abstraction for irrigation severely reduced the flows arriving to the border and flow regime was highly irregular.

Hydrogramme at the border of the Guadiana river obtained by simulation for pristine conditions (blue) and with the uses as set up in 1990 (red). Dam builders – Douro river basin Dam builders – Douro river basin

B.Casares rio Porma B.Cervera B.Duerna [37] B.Vidrieros [10] [32] B.Riaño [86] B.Porma [664] [317] B.Requejada B.Eria [65] [62] B.Camporredondo rio Ricobayo [70] B.Barrios de Luna B.Cernadilla [308] B.de Aguilar del Campo [255] [247] B.Uzquiza B.Cuerda del Pozo B.Valparaíso B.Compuerto [73] B.Arlazon [169] [229] rio Esla [95] rio Arlazon [20] B.N.S.Argavalanza Tâmega [49] B.Pereira B.Tuela rio Carrion [2] [2] B.los Rabanos B.Ricobayo rio Valderaduey +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ [6] Cávado +++ [1148] B.Arlanza +++ +++ B.Roman rio [140] Alto Rabagão +++ B.Castro B.Veladro +++ [1.5] (569) Tua ++++ [350] Sabor ++++ [27] Vinhais +++ Vidago B.Miranda + Mente Alto (28) (134) (296) Rabaçal B.S.Jose rio Riaza Tâmega Sampaio + B.Villalcampo B.Picote + [6] rio Eresma (800) [66] (63) + Alvão ++ rio Guareña (71) rio Duraton Padroselo B.Bemposta B.Linares del Arroyo Azibo (129) + B.Lastras (68) Daivões + rio Adaja [58] Rebordelo (35) ++ (66) (312) [97] Quinta das Laranjeiras B.las Venencias (966) + [5] ++ rio Tormes Fridão + B.Aldeadavila (210) [115] Feiticeiro B.Almendra ++ [2649] B.Burgomillodo (32) ++ Torrão Régua FozTua ++ B.Saucelle [15] (115) Carrapatelo Pocinho ++ B.Voltoya (340) (83) + [169] (148) (95) ++ [6] ++ ++ B.Seropes ++ B.Villagonzalo Valeira ++ Crestuma Castelo + [6] (99) + (110) Paiva ++ B.El Milagro ++ rio Águeda B.Cogotas (44) Varosa Vilar + [2] [59] (15) (100) Foz Coa + B.Águeda + B.S.Teresa (702) + [22] Alvarenga + Castillejos [496] + B.Torreiglesias (842) + [140] + [96] Pero Martins + (380) + + Castro Daire + Fuenteguinaldo Távora + LEGENDA (65) + [175] B.Aravale El Duque B.Torrecaballeros Sra. Monforte + + [2] ESPANHA (263) + Portela + + B.Iruena Barragem construída (151) + [210] Paiva + + Atalaia + + ESPANHA Barragem em projecto PORTUGAL (460) + + + + + PORTUGAL + + + Barragem construída + + Hidroeléctrica + Sabugal + Hidroagricola + Coa (114) + Barragem em projecto

+++++++ Fronteira

APROVEITAMENTOS HIDRÁULICOS EXISTENTES E EM PROJECTO NA BACIA DO DOURO Dam builders – Tajo river basin Dam builders – Tajo river basin Dam builders – Guadiana river basin Dam builders – Guadiana river basin

Cancho del Fresno(15) Transvase do Segura La Garita Puertos (91) Abrilongo Ruecas (44) Guarranque (21) Villar del Rey Sierrra Torre de Abraham(78, 190) (58) (123) Brava(232) A. Ruecas (0) Piedrala (15) Boqueron Bejida(15) (6) Aljucen Proserpina Cubillar Gargaligas(21) Riscos (102) (11) (10) Higuelas (21) (203) Hornotejero (24) Alcobilla(42) R. Gévora Cerros Alcolorin Gasset R. Zápaton Cornalbo Verdes(20) (51) (42) (10) R. Ruecas R. Bullaque R. Ciguela Canchales Burdalo(68) R. Bañuelos (40) El Canal Garcia de (25) R. Caia R. Burdalo Sola(427) Los Orellana Reznos(32) R. Guadiana (478) R. Guadiana

Montijo(11) El Vicario Zujar Cijara(1416) (52) Vallehermoso R. R. Matachel (301) (7) Golodron Alange (93) La Serena R. Jabalon Lucefécit Piedra (845) Peñarroya (2828) Tirteafuera(74) (10) Aguda (47) Nogales Vigia (16) Las Cruces Piedraescrita Vega del Pardiela (15) Marisanchez (17) R. Lucefécit (33) (81) Jabalon (33) (41) R. Alcarrache Aguijon(11) Molino Villalba de (34) R. Degebe los Barros (80) Llerena R. Zucar Brovales Ardila Monte Alqueva (7) (7) (100) Novo (3150) (15) R. Ardila Valuengo (10) Tentudia Pedrogão (5) (60)

R. Enxoé Enxoé (10)

Legenda Oeiras R.Oeiras (12) Chança (386) Barragem em exploração em Espanha R Chança (25) Capacidade útil Açude Guadiana Barragem em exploração em Portugal (25) Capacidade útil

Andevalo Barragem em projecto ou construção (25) - Capacidade útil Foupana S.Lucar (1025) (130) (94) Canal de rega Canal Chança-Piedras R.Odeleite

Odeleite (130) Beliche R. Beliche (48)

DAMS AND WATER TRANSFERS IN THE GUADIANA RIVER BASIN ATLANTIC OCEAN

Tajo river basin – Installed flow regulation capacity The 1993 crisis

A crisis in the relations between the two States arose in 1993

In 1993 a draft National Water Plan was submitted to public consultation in Spain that was badly received by the Portuguese public. A second water transfer in direction of the Southern river basins, again in the order of 1.000 hm3, was considered, now having as origin the Douro basin. The two governments decided to start negotiating a new water Convention. The negotiations of the new Convention

The negotiations for the new Convention started in 1994 and by the end of that year the Ministers of the Environment met in order to establish the working programme and agreed on the principles that should be considered (the so called Oporto Declaration). The number of delegates in each side was limited and consisted of: . The Water Directors; . Diplomats; . Jurists; . Experts on hydrology and hydraulics; . On the Spanish side, representatives of the hydraulic administration of the regions concerned; The Working Group met al least every 6 months alternatively in Spain and Portugal. Besides that the Ministers and the Water Directors met regularly in Brussels at the Environment Councils and also at the Spanish-Portuguese yearly Summits chaired by the Heads of Government of both States. The progresses registered were then evaluated and disputes settled by political arbitration. The negotiations of the new Convention

Negotiations took advantage from the fact that: . Relations between the two Governments were very good and a Treaty on Friendship and Cooperation had just been signed; . The two States were by that time members of the EU and had both to abide to very stringent water directives, namely in what concerns the prevention of water pollution and the protection of the environment; . The two States had already subscribed the UNECE conventions (Helsinki, Aarhus, Espoo); . There was a long-lasting and solid tradition of fruitful cooperation between the authorities of the two States on transboundary water issues; the Commission that had been created for the management of the Conventions in place was meeting from time to time and people knew each other. Confidence had been created. For Portugal, it was very important to arrive to a satisfactory result as for the flows issue, for Spain it was more the definition of a framework for further water uses that was at stake. It was Portugal’s responsibility to take the lead and present proposals (the petitioner). Kew words of the new Convention

 Cooperation

 Coordination

 Environment protection

 Sustainable development

 Exchange of information

 Consultation

 Impacts mitigation– no harm principle

 Flows Guaranties – Principle of equitable and reasonable use

 Development of the Law The negotiations of the new Convention

For all issues, with the exception of the flows regime issue, there were already formulae that had been accepted by the two Parties (in the EU water directives, the UNECE conventions, the 1966 Helsinki rules, the New York Convention). But these formulae had to be adapted: . To the specificities of the shared rivers; . To the previous water agreements (the 1964 and 1968 Water Conventions, which stayed in place); . To the de facto situations (the already built dams, the water transfers, the irrigation perimeters); . To the specificities of the State organisation and administration of the two States. All this had to be studied and considered by the two Parties and very thorough and extensive exchange of information followed. But in what concerns the flows regime, even if some precedents existed, it was clear from the first minute that we had to innovate.

Studies made by the Portuguese Party and presented to the Spanish Party

Study of the flows regime in pristine conditions

Douro 185 340 560 5300

340 2650 185 560

2530 860

5300 2650 1120 10850 1360 1360 2870 540 1420 1540 23130 1305

1475 630 3050 990 13900 1540 1475 3000 630

990 50

Escoamento total 23130 hm³/ano Gerado em Espanha 14980 65 % Gerado em Portugal 8150 35 % Studies made by the Portuguese Party and presented to the Spanish Party Study of water uses and flows regime in modified conditions

5300 2650 (Transferência para o Sil) 290 000 ha

Douro 155 370 121 800 ha 1840 1085 60 150 780 180

182 400 ha 930 5050 60 80 100 130

285 1360 14201330 160 60 3630 1930 300 380 7010 770 60 80 4605 680 16000 60 170 640 30 40 130 2125 2260 80 100 9270 45 55 1000 97 150 ha 200 990 200 150 129 600 ha 50 50 770 147 000 ha 160 1540 111 600 ha 3095 3000

Escoamentos gerados em cada zona Escoamentos entre zonas Fornecimentos para rega Fornecimentos urbanos e industriais Retornos de rega Retornos urbanos e industriais Evaporação em albufeiras Studies made by the Portuguese Party and presented to the Spanish Party

Study of hydrologic series at the entrance of Portugal and other relevant sections

Douro Studies made by the Portuguese Party and presented to the Spanish Party

Studies on the correlation between rainfall and runoff Studies made by the Portuguese Party and presented to the Spanish Party

The Portuguese Party presented proposals for minimum annual flows at the relevant sections: . At the entrance sections of the border stretches of the rivers and the sections where the rivers enter into Portugal, thus creating an obligation to the Spanish Party. . At the entrance of the estuaries, thus creating an obligation to the Portuguese Party; For the Minho, Douro and Tajo rivers, exceptions were considered whenever the pluviometria is below some reference values (by the end of the rainy season) as measured in pluviometric posts that have been agreed as representative. For the Guadiana river, where the installed regulating capacity in Spain doubles the mean annual flow at the entrance into Portugal, minimum flows that depend not only on rainfall but also on the volumes of water stored in Spain were agreed. That is to say that Spain agreed to allocate some of its regulation capacity installed upstream of the border for the service of Portuguese needs. The negotiations of the new Convention

The specific elements that were decisive for reaching the agreement were: . Only sound proposals were presented by any of the parties at the table of negotiations, not abstractions with no justification; . All proposals had to be balanced and achievable without imposing unbearable burden upon the other party; . Portugal being the downstream country and therefore the main beneficiary of the agreed flow regime, it was to him to prove that in each and every case there was a benefit for Spain on what was being proposed; . The views of the two parties were reconciled by including in the agreement flow obligation at the entrance of the estuaries, to be guaranteed by Portugal; . It was also important to accept that in case of droughts, as defined in the convention, the parties are exempted from compliance of the agreed flow regime The negotiations of the new Convention

The benefits for the two Parties are the following: . In defining and regulating the flows that Spain has to guarantee at the entrance of the Portuguese territory the convention offers guarantees of water resources to Portugal that allow the development of hydraulic projects on a more solid basis; . In defining and regulating flows at the entrance of the Portuguese territory the convention defines limits to the use of the water resources by Spain in its territory in a double way:  Limits the expansion of consumptive uses (irrigation, water transfers);  At the same time, allows for the expansion of consumptive uses up to this top, which Portugal will not contest; . In defining and regulating flows at the entrance of the estuaries the convention defines limits to the use of the water resources by Portugal in its territory; Studies made by the Portuguese Party and presented to the Spanish Party

Proof that the proposed regime would not constitute any severe harm to Spanish interests had to be presented.

DOURO Studies made by the Portuguese Party and presented to the Spanish Party

The same with Portuguese interests.

TAJO Flow regime of the Albufeira Convention, 1998

3.700 hm3

3.500 hm3 5.000 hm3 3.800 hm3

2.700 hm3 600 hm3 4.000 hm3 500 hm3 400 hm3 2 m3/s

2 m3/s Flow regime of the Albufeira Convention for the Guadiana

For the Guadiana river the flow regime is more complex, but the principle is the same: there is exception whenever the rainfall accumulated since the beginning of the hydrologic year and the volumes of water stored in the reference reservoirs are bellow certain levels. The installed regulation capacity in Spain upstream the border is in the order of 8.000 hm3.

(hm3) Flow regime of the Albufeira Convention for the Guadiana

Hydrogramme of river flows at the border, with the Convention and without the Convention, obtained by simulation

8000

6000

4000

Caudais anuais (hm3) anuais Caudais 2000

0

1946 1948 1950

1952 1954 1956 1958 1960

1962 1964 1966 1968

1970 1972 1974 1976 1978

1980 1982 1984

Com Convenção Sem Convenção Flow regime of the Albufeira Convention for the Guadiana

Histogram of annual flows at the Histogram of annual flows at the border without the Convention border with the Convention

45 45

40 40

35 35

30 30

25 25

20 20

15 15

Frequencia relativa (%) relativa Frequencia Frequencia relativa (%) relativa Frequencia

10 10

5 5

0 0 300 600 900 1200 1500 2000 3000 5000 More 300 600 900 1200 1500 2000 3000 5000 More Classes (Caudais em hm3) Classes (Caudais em hm3) Flow regime of the 2008 Protocol to the Albufeira Convention

In 2008 the flow regime was detailed by means of . The definition of minimum quarterly flows; . The definition of minimum weekly flows;

Annual Douro river at the border

Quarter

Weekly Lessons learned

The success of the Albufeira Convention is the result of a stubborn and very serious work that went on for 5 years. The fact that the Parties had a common legal framework, the EU water and environment directives and the UNECE conventions, was very important for the successful conclusion of the Convention. The technical study of the solutions took some time but proved to be crucial for the success of the negotiations. The Portuguese Party, as the downstream country, had the initiative most of the time. The seriousness of the negotiations consisted in not presenting biased proposals, proposals that could not be complied with by the other Party without severely affecting its sovereignty in what concerns water resources management. We both tried to systematically understand the other Party’s positions and its reasons and point of view. The presence of Diplomats at the negotiating table was very important. Afterword

In the year 2000 a new National Hydrologic Plan was developed in Spain that again considered the transfer of water from the Douro river to the South (1.000 hm3). Having simulated the transfer the Spanish authorities arrived to the conclusion that it was not feasible if the agreed flow regime was to be respected and the project was abandoned. Many thanks for your attention

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