The Sea of Cortez, the desert, and one house

What is the Sea of Cortez, and where does Los Cabos sit on it?

It is the Gulf of California, the narrow marginal sea between mainland Mexico and the Baja California peninsula, 1,100 km long and 180 km wide at its mouth over an area of 210,000 km². Los Cabos sits at that mouth, at the southern end of the peninsula, where the gulf opens to the Pacific and the seabed falls away steeply a short distance offshore.

The two names are the same body of water, and the official Mexican description is the geographic one. Conabio gives its shape as una franja acuática alargada y estrecha de 1,100 km de largo y 180 km de ancho en su boca, and the Comisión Nacional de Áreas Naturales Protegidas uses the other name for the same sea when it describes the protected areas of el Mar de Cortés. The scale of what is protected there is unusual: the World Heritage nomination comprende 244 islas e islotes y áreas costeras ubicadas en territorio de los estados de Baja California, Baja California Sur, Sonora, Sinaloa y Nayarit, and the same document records the name the sea is best known by outside Mexico, “el Acuario del Mundo” por Jacques Cousteau.

Where Los Cabos sits is worth stating precisely, because the depth arrives almost at the shore. Conanp's file on the protected area at Cabo San Lucas describes the submarine canyon that begins in the bay itself: it inicia en una profundidad de 10 a 15 m y corre paralelo a la costa sur, sale de la bahía y desemboca en la porción central-oeste de la boca del Golfo de California, a una profundidad de más de 2,000 m. The cape was given federal protection for that reason and not for the beach: the 1973 decree established a “Zona de Refugio Submarino de Flora, Fauna y Condiciones Ecológicas del Fondo” whose declared objectives were to conservar con toda originalidad el espectáculo de las cascadas de arena que se presentan en el fondo marino and to permitir estudiar los procesos de erosión en los cañones submarinos, and it is administered today as the Área de Protección de Flora y Fauna Cabo San Lucas.

What follows from the position, for somebody who owns a house here rather than visits one, is narrower than the geography suggests. It is not that the sea is more aggressive than another sea; it is that the house stands at a corner, with open water on more than one side and nothing between it and the water to slow the air down, and that everything behind it is desert. Those are two separate loads on the same building, and the rest of this guide takes them one at a time.

What does salt air do to a house that faces the water?

It deposits chloride on every surface continuously, and in Mexico that is a graded quantity rather than an adjective: the federal electricity utility specifies exposed hardware against a salt-fog salinity scale that runs from light to very high. The consequence for a house is asymmetric, and the utility states the asymmetry outright — equipment made for a salty zone can be used in a clean one, and equipment made for a clean zone cannot be moved into a salty one.

The scale is published in specification CFE 52000-91 for pole-type insulators, and it has four steps measured in kilograms of salt per cubic metre: Ligero, 5 a 14; Medio, 14 a 40; Alto, 40 a 112; and Muy Alto, > 160. Each step buys more leakage distance and a different material, and above a certain step the metal itself changes: the specification's own note is that el acero inoxidable se debe utilizar para zonas de alta y muy alta contaminación. How long the qualification takes is the part that says most about the exposure — an accelerated ageing test of 5 000 h en cámara de niebla salina y 8 000 h en cámara de esfuerzos múltiples.

The one-way rule is the sentence to carry away from all of it, because it applies to far more than insulators. The specification says that los aisladores para contaminación pueden ser utilizados en zonas de descargas atmosféricas. Sin embargo, los aisladores para descargas atmosféricas no pueden ser utilizados en zonas de contaminación. Read as a maintenance rule it means that on this coast the safe error is always the more expensive specification, and that a fitting chosen correctly for a house two hundred kilometres inland is the wrong fitting here — not worn out early, wrong from the day it was installed. The same document adds the other half of the metal problem, which is what happens when two of them touch: el herraje de aluminio no se debe utilizar con conductores de cobre, debido al fuerte par galvánico que se genera.

For a house the practical question is therefore not whether the air is salty but what was specified, by whom, and when. A house bought complete came with somebody else's answers in every hinge, rail, bolt, pump and outdoor condenser, and a house bought with its equipment inherits the specification along with the fittings. The work of reading them back is ordinary and unglamorous, and it belongs in the preventive maintenance plan rather than in a repair: a list of what is actually installed, against a list of what this exposure asks for, written once and corrected as things are replaced.

What does the desert behind the coast do to the same house?

It never washes the salt off, and it works the materials hard in the other direction. Conagua's study of the aquifer under San José del Cabo puts average annual rainfall at 421.5 mm against a potential evaporation of 2,131.5 mm — about five times as much water leaving as arriving — in a climate the same document classifies as very dry and hot.

The classification is not a figure of speech. Conagua records that on the low ground and along the coastline el clima se caracteriza por ser BW (h´) hw (x´) Muy seco cálido con sus variantes, and from eight climate stations with records running as far back as 1926 it derives valores promedio anuales de precipitación y temperatura 421.5 mm, 23.5 °C and, for potential evaporation, un valor de 2,131.5 mm anuales. The temperature range on the same materials is wide for a coast: extremes run de 42°C, registrada en el mes de julio, a -2°C en el mes de febrero, and annual rainfall itself swings entre 230.5 a 522.4 mm anuales, so two consecutive years can differ by more than a factor of two.

The sentence that joins the two halves of this guide is also Conagua's, and it is the reason a maintenance calendar written for anywhere else does not transfer. The region, the study says, se caracteriza por presentar periodos prolongados de sequía, que eventualmente son interrumpidos por la incidencia de tormentas tropicales y huracanes. Put beside the salt, that means the only thing that rinses a wall on this coast arrives inside the event that threatens it. Salt accumulates for months with nothing to remove it, dust settles in the same dry air, and then the water comes all at once and in the worst possible company.

This is also why the built vocabulary of the coast is what it is, and why the shade is structural rather than decorative. The regional timber and thatch that do that work here — a palapa or a palo de arco pergola — are described where they belong, on the service page for this kind of house, and they are not the same materials as anywhere else we work. What the dry air changes about looking after them is only the interval: nothing rots quickly, and nothing gets cleaned by the weather either, so the condition of a surface on this coast is almost exactly the sum of the days since somebody last touched it.

What does the water supply of a desert town mean for a house that stands empty?

It means the supply is administered rather than assumed, and the administration is published. The aquifer under San José del Cabo is in deficit and closed to new concessions, and the town's mains supply is issued as a rotating schedule that changes by zone — neither of which an empty house can notice on its own.

The deficit is arithmetic and Conagua shows the working. Recharge is 35.9 hm³ a year, committed natural discharge 10.8, and registered extraction 37,593,828 m3 anuales, que reporta el Registro Público de Derechos de Agua (REPDA), which leaves the availability negative: el resultado indica que no existe un volumen disponible para otorgar nuevas concesiones; por el contrario el déficit es de 12,493,828 m3 anuales. The legal position is older than the number. The aquifer's whole territory se encuentra vedado y sujeto a las disposiciones del “Acuerdo que establece el Distrito Nacional de Riego de Baja California Sur”, published in 1954, and that ban is veda se clasifica como tipo III, en la que la capacidad de los mantos acuíferos permite extracciones limitadas para usos domésticos, industriales, de riego y otros.

What reaches the house from all of that is a schedule rather than a shortage. The municipal utility publishes its rotating supply programme zone by zone and reissues it when conditions change, which is set out with the rest of what this coast rewrites service by service on the page for Los Cabos. The consequence for a house standing empty is that its water behaviour is entirely invisible from outside it: a cistern that fills on days the owner does not know, a pump that can be asked to lift from an empty tank, and a leak that runs at the same rate whether or not anybody is there to hear it.

So the answer for a closed house is a reading rather than an inspection, and it has to be a number. Somebody writes down the meter and the cistern level on the same day of the week, dated, and the value of that line is not the day it was taken but the month it can be compared with — a leak on a desert coast shows up as a reading that stopped falling back, long before it shows up as anything a visitor could see.

Where those readings live decides whether they survive the year. A number in a message is gone by the time anyone wants to compare it, so it belongs with the amounts in the monthly owner statement, where a consumption line and the invoice that came with it are already reconciled and where a question asked in March about a July week has somewhere to land.

What did Hurricane Odile change about how houses there are built and checked?

It set the measured intensity of record for this tip of the peninsula, and it showed how long the coast stays unreachable afterwards. What that changes for an owner is the deadline rather than the specification: everything that has to hold has to be sound before the season, because for weeks after a storm of that size nobody can get to the house.

The measurements are the National Hurricane Center's, in its own report on the storm, and they are worth reading in that order. Odile made landfall with 110-kt winds (category 3 on the Saffir-Simpson Hurricane Wind Scale) on the southern tip of the Baja California peninsula at 0445 UTC 15 September, just to the east of Cabo San Lucas, and it was the first major hurricane to strike this region in 25 years and tied with Hurricane Olivia of 1967 as the strongest landfalling hurricane in Baja California in the historical record. The approach left almost no time to do anything late: the cyclone strengthened from an estimated 65 kt at 0600 UTC 13 September to its peak intensity of 120 kt 24 h later.

The part that rewrites a checking calendar is what stopped working, and for how long. The same report records that windows were blown out of many of the luxury high-rise hotels lining the shore of Cabo San Lucas and adjacent areas, that the hurricane devastated the region’s electrical infrastructure, taking out about 550 high-tension transmission towers and 3,400 distribution posts, and that in the state over 239,000 people (over 90% of the population) were left without electricity. In San José del Cabo there was severe damage reported, with drinking water unavailable and communications left inoperative, and the way out of the region closed for a month: except for shipments of humanitarian relief, flights into and out of the airport were suspended until about a month after Odile’s landfall.

Read from an owner's side, that is not a story about wind speed but about a window of access that shuts. A house on this coast is checked on a calendar whose only hard date is the one before the season, because after an event of that size there is no power to run a pump, no water to flush a line, no phone to describe a problem with and no flight to put a specialist on. The grid is a useful reminder of the scale, since it is the one system on this coast that is already specified for the salt and was still down for weeks.

One thing this guide does not do is forecast. A hurricane outlook belongs to the agency that issues it, and the figures above are the National Hurricane Center's record of one storm that has already happened, not a statement about any season to come. What an absent owner actually follows once a warning is issued — who decides what, and in which order — is the subject of the guide to a hurricane and what an owner checks, written for the other coast and the same problem.

What should be looked at, and how often, on a house nobody is living in?

Two lists on two different clocks: what the salt is doing, which is continuous and needs a fixed interval, and what the season requires, which has a single deadline. Neither is a walk-through — both are agreed in writing before the year starts, and both are worth only as much as the previous note they can be compared with.

The reason the two lists cannot be merged into one visit is that they fail differently. Salt and dry heat work slowly and never announce anything, so they are caught by comparison: the same frame, the same fitting, the same reading, at an interval short enough that a change is small when it is found. The season does the opposite — it arrives on a date and closes the road behind it — so everything it touches has one deadline and no second chance. The table below splits the year on that basis, and it is the whole of the maintenance shape this coast asks for.

The interval matters more than the thoroughness, and that is the least intuitive thing about a closed house on this coast. A single very careful inspection produces a description; twelve ordinary ones produce a series, and only a series can show that a hinge has been getting worse for four months or that a cistern has stopped recovering. It is also the cheaper of the two, because almost everything found early on a desert coast is still a cleaning job rather than a replacement.

None of it is a promise about the weather, and none of it needs to be. The sea will keep depositing salt at a rate nobody controls and the desert will keep not washing it off, and the only variable an absent owner actually holds is how many days pass between one look and the next. Agreeing that number, in writing, before the year begins is the substance of an annual plan for the house, and it is the one decision on this list that cannot be made after the fact.