Drought institutions of colonial Mexico: water turns, water judges and the public granary
Colonial Mexico met an unreliable climate with institutions. Water was divided among landowners by the tanda, a system of turns counted in days, with water judges to adjudicate; grain was held against failed harvests in the posito and the Real alhondiga; disputes over water and flood damage went to court, and indigenous communities used those courts. The archives show the arrangements holding against ordinary variability, failing against sustained crisis, and they show who paid.
Why this wins its question: Colonial Spanish America is usually asked whether it extracted, and answered in silver. This asks a duller and more revealing question - what happened when the rain failed - and answers it from the litigation and municipal records: turns of water counted in days, appointed water judges, an allocation the landowners confirmed in writing, 5,000 pesos raised among them in 1780 for head gates on Lake Yuriria, public granaries in the principal cities, and a 1614 settlement that put a mill and an indigenous irrigation community in sequence on the same river instead of choosing between them. The same peer-reviewed source supplies the cost, so the object never has to balance a good institution against an outside critic: money from Spaniards and labour from indigenous residents at Celaya in 1692, Augustinians dominating the water they had helped fund, a dam left unmaintained by its council, the famine of 1785-86 that the buffers did not stop, and a formidable inequality the crises exposed.
Claims
Every assertion below is bound to registered sources and carries its own confidence. Weight them; do not treat the page as uniformly authoritative.
The evidence is an administrative paper trail rather than a chronicle. The study behind these claims works from the Archivo General de la Nacion in Mexico City - the ramos of Tierras, Rios y Acequias, Ayuntamientos, Alhondigas and Mercedes - together with the municipal historical archives of Oaxaca, Leon in Guanajuato and Chihuahua.
By the second half of the seventeenth century water in the Valle de Santiago was shared by formalised arrangement. Under the tanda system it was divided between landowners in turns, usually measured in days of water; water judges were appointed to adjudicate fair distribution; and all the landowners of the valley met to decide collectively and to confirm the days of access in writing.
A dispute of 1614 over the Lerma river set the indigenous residents of Acambaro, who needed the water to irrigate, against Francisco de Villadiego Senderos, who needed it to turn his mill. It was settled by sequence rather than by exclusion: the water was to run the mill first, and the remanente, the surplus that came off it, was then to be used for irrigation.
Drought in 1780 produced a collective public work. Landowners of the Valle de Santiago and the Augustinians devised a scheme to draw on the water of Lake Yuriria, regulating its connection to the Lerma with head gates at the entrance to the channel, and all the landowners of the valley were charged with raising 5,000 pesos between them to finance the construction.
Who paid and who benefited did not match. At Celaya after the flood of 1692 the Spanish residents were asked for financial contributions to the dam works while the indigenous residents were asked for their labour in building it; and at Yuriria the Augustinians ultimately dominated the manipulation of the water the collective scheme had made available. The collective form is real and so is the hierarchy inside it.
Against harvest failure the instrument was storage. Government-sponsored grain stores, the Reales alhondigas, and granaries, the positos, were established in the principal cities of the country and stocked by the authorities in years of poor or failed harvest. The experience of drought appears to have prompted the founding of a number of these facilities rather than merely testing them.
The buffers had a known ceiling. Irrigation, trading and storage were relatively effective against normal or expected climatic variability and against a single year of hardship; consecutive periods of anomalous weather, or an unusual event striking a society already made vulnerable, defeated them. The crisis of 1785-86 brought famine, epidemic disease, death and economic recession to most of the country.
Litigation was itself an adaptive tool, and indigenous communities used it. The community of Xoxocotlan in Oaxaca seized on a flood of 1775 that moved the channel of the river Atoyac, and on the continued shifting of the channel between 1775 and 1785, to argue for a redefinition of the boundary between its lands and those of the neighbouring hacienda of San Miguel; the suit is accompanied by a sequence of maps and runs in the record to 1804.
The works could fail for want of upkeep rather than for want of design. Later damaging floods show one of these schemes to have been only partly successful, and largely because the local council failed to maintain the dam.
The overall reading is that climatic stress in colonial Mexico did not produce societal disintegration but acted as a trigger to adaptation, with social cohesion and the capacity to self-organise offered as the explanation. An overview article in the same journal issue counts colonial Mexico among four cases in which resilience allowed fundamental change without simplification or breakdown, and attributes resilience generally to identified options, improved understanding, cultural solidarity, leadership and opportunities for participation - but that is a listing in a survey rather than an independent study of Mexico, so the corroboration it offers is weak.
The same author records the counterweight. Disputes over land and water across and between all sectors of society increased during these events; the climate and environmental crises of the later colonial period helped expose a growing and formidable inequality in Mexican society; and the tensions may have contributed to the general dissatisfaction that culminated in the drive for independence.