Water Supply in Los Cabos: What Every Property Buyer Should Know

Water supply is the question every serious Cabo buyer needs to ask — and the one most real estate agents skip. Los Cabos faces a municipal shortfall of 420 to 600 liters per second, but the full picture is more nuanced than the headlines suggest.

The Current Water Situation — Honestly

Let me be direct: Los Cabos has a water supply problem. The municipal utility OOMSAPAS (Organismo Operador Municipal del Sistema de Agua Potable, Alcantarillado y Saneamiento) faces a deficit of 420 to 600 liters per second in its system. In 2025, weeks-long outages triggered street protests and road blockades in more than 20 neighborhoods in Cabo San Lucas.

But context matters. The water stress is not uniform across Los Cabos. It is concentrated in Cabo San Lucas proper — particularly in colonias (neighborhoods) that grew faster than infrastructure could follow. San Jose del Cabo has better supply. Master-planned communities and luxury developments often operate their own water treatment. And a major new desalination plant is under construction.

For property buyers, the question is not "does Cabo have water?" — it is "what is the water situation in the specific community where I am buying?" The answers vary dramatically.

The Desalination Story: Plant 1 and Plant 2

Plant 1: The Underperformer

The existing Cabo San Lucas desalination plant was built in 2006 by GS Inima under a public-private partnership with OOMSAPAS. It was designed to produce 200 liters per second — enough to meaningfully supplement groundwater sources. The problem: it is currently operating at approximately 36% capacity, producing roughly 90 liters per second. Chronic underperformance is a major contributor to the current deficit.

Plant 2: The Hope

A second desalination plant is being built by Acciona under a new PPP agreement with OOMSAPAS. The numbers: 250 liters per second capacity, approximately EUR 134.5 million in investment, 32% complete as of early 2025, with a target completion date of October 2026.

If Plant 2 delivers on schedule and Plant 1 can be restored to higher output, the combined desalination capacity could reach 450 L/s — a transformative increase. But "if" is doing heavy lifting in that sentence. Construction timelines in Mexico routinely extend, and Plant 1's restoration depends on investment in aging equipment.

Private Desalination: The Developer Response

The smartest developers in Los Cabos stopped waiting for OOMSAPAS to solve the problem. Multiple luxury communities now operate their own desalination or advanced water treatment systems:

• Chileno Bay (Auberge) has its own on-site desalination plant, making it fully independent of the municipal supply for potable water.
• New hotel and resort developments are now required by the municipality to install their own desalination capacity — a policy that did not exist a decade ago.
• TSG Water operates private desalination and wastewater systems for multiple resorts and developments across Los Cabos.
• The Los Cabos Coordinating Council (a business group) began advancing private desalination plants in late 2024, including a $40 million reverse-osmosis facility in partnership with Crown Electrokinetics and 529 Capital.

For buyers, this trend has a clear implication: communities with private water infrastructure carry less risk. When you are evaluating a property in a master-planned community, ask specifically whether the development operates its own water treatment or depends entirely on OOMSAPAS.

The Cistern and Tinaco System: How Homes Actually Get Water

If you are buying or building in Los Cabos, you need to understand the standard residential water system. It is different from what you are used to in the US, but it works:

1. Municipal connection or pipa delivery fills a ground-level cisterna (underground or ground-level tank). Standard home cisterns hold 5,000 to 10,000 liters.
2. A pump moves water from the cistern up to a rooftop tinaco — typically a 1,100-liter Rotoplas tank.
3. Gravity feeds water from the tinaco to your fixtures, providing constant pressure without relying on the pump running continuously.

This two-stage system buffers against intermittent municipal supply. When the OOMSAPAS line is flowing, your cistern fills. When it is not, you draw from stored water. Properties with larger cisterns (10,000+ liters) can go longer between fills — important during rationing periods.

For new construction, I recommend oversizing the cistern. The incremental cost of a 10,000-liter cistern versus a 5,000-liter cistern is minimal during construction and provides meaningful peace of mind. Add a float valve and low-water alarm so you know when to call a pipa before you run dry.

Water Quality: What You Can Drink

OOMSAPAS states that municipal water meets Mexican drinking water standards (NOM-127-SSA1). The practical consensus among expats and local medical professionals: safe for bathing and cooking, not recommended for drinking directly from the tap due to aging pipe infrastructure between the treatment point and your home.

Most residents use one of three solutions:

• Garrafones: 20-liter (5-gallon) jugs delivered to your home. Cost: approximately $2-3 USD per jug. This is what most Mexican households use.
• Point-of-use filtration: Under-sink reverse osmosis systems that produce drinking-quality water from the tap. Installation cost: $300-$600 for a quality system. This is the most common solution for foreign homeowners.
• Whole-house filtration: Multi-stage systems that treat all incoming water. More expensive ($2,000-$5,000) but protects fixtures and appliances from sediment and mineral buildup in addition to providing drinking water.

What Buyers Should Do: The Water Due Diligence Checklist

Before buying any property in Los Cabos, add these water-specific questions to your due diligence checklist:

1. Does the community operate its own desalination or water treatment? If yes, what is the capacity and who maintains it?
2. What is the OOMSAPAS service history for this area? How often are there rationing periods?
3. What size is the property's cistern? When was it last cleaned and inspected?
4. Is there a well on the property or in the community? What is the water table depth and quality?
5. What filtration systems are installed? When were the filters last replaced?
6. For new construction: what cistern size is specified? Can it be upgraded?

Water is not a reason to avoid buying in Los Cabos. It is a reason to buy informed. The communities with the best water infrastructure — private desalination, oversized storage, modern filtration — are precisely the ones where long-term property values are most secure. Infrastructure investment tracks directly to appreciation.