A marketplace for water

Markets for the world's most critical resource.

Water is scarce and badly allocated. Hydraux is building the market infrastructure to trade water safely and transparently, starting in California's groundwater basins.

The problem
Scarcity and misallocation
The approach
Market design and blockchain
Starting with
California groundwater
The problem

Scarce water, and no market to move it.

The American West is running short of water. Years of overdraft, drought, and tightening legal limits leave less to go around each season. But scarcity is only half the problem: the water that remains is badly allocated. One grower fallows a field for lack of water while a neighbor sits on a surplus they won't use. The gains from reallocation are large, yet moving water still means bilateral deals, legal review, and months of delay because no real market exists to do it.

1,200 yrs
The American West is in its driest stretch in at least twelve centuries.
Nature Climate Change
40M
People who rely on the Colorado River, where demand has outrun supply for years.
US Bureau of Reclamation
~2M AF
How much more groundwater California's San Joaquin Valley pumps than it replenishes, every year.
PPIC
900K ac
Farmland that may leave production by 2040 to bring the valley's basins into balance.
PPIC

The dysfunction shows up in the price. In a dry year, subsidized supply in one part of the Central Valley can clear under $100 an acre-foot while a grower a few counties away pays north of $2,000 for the same water. A functioning market closes that gap.


Why this is hard

You can't just put water on an exchange.

Markets move oil, power, and grain with ease. Water has resisted them, because three things make it uniquely hard to trade.

Heterogeneity

No standardized unit

An acre-foot's value depends on its location, its timing, and the seniority of the right behind it. Water is not standardized the way a barrel of oil is, so there is no common unit to list and trade, the precondition every liquid market takes for granted.

Externalities

Every trade has third parties

Users share rivers and aquifers, so a trade between two parties imposes externalities on a third. A field consumes only part of what it diverts; the rest returns as flow that downstream users and ecosystems depend on. Sell more than the consumed share and the water comes out of someone else's supply. Pricing and clearing have to internalize that, or the market does real downstream harm.

Water law

A century of senior rights

Water rights are a layered system of seniority and overlapping claims built over more than a century. Any valid trade has to respect that priority structure and the basin's hydrological constraints at once. Get it wrong and a third party is injured, which is why trading has stayed cautious and thin.

Water needs a market that understands water.


The approach

Built for the physics and the law of water.

Growers trade in the allocations they already hold. Around that, Hydraux provides three capabilities an ordinary exchange cannot.

Market design

Built to clear thin markets

Water markets are thin: in any season only a handful of participants trade. Hydraux applies smart-market mechanisms, drawn from decades of market-design research, to match counterparties and surface a clearing price even when liquidity is low. It is what turns scattered bilateral deals into a real market.

Blockchain

Trust without a middleman

Water markets fail on trust: neighbors doubt each other, and few trust an agency to keep the books. Hydraux records every allocation and trade on a shared, immutable ledger that no single party controls. Ownership is unambiguous, and the full history is auditable by anyone with access.

Constraint engine

Safe by design

Before a trade clears, the constraint engine screens it against the basin's hydrological constraints, return flows, environmental flows, seniority, and local rules, drawing on satellite measurement data. Any trade that would cause downstream harm is trimmed or blocked. The check runs on every trade, so the market stays open and fast without sacrificing the basin.

Efficient like a market, trustworthy like a public record, safe by design.


Who it's for

Built for both sides of the basin.

A district adopts Hydraux to operate the market. Its growers use it to trade. Each side gets a tool built for what it actually needs.

Hydraux gives the district a market its growers can use to reallocate water, with the district’s own rules enforced on every trade and full oversight throughout. It is demand management that works with your growers rather than against them.

A demand-management tool for SGMA

Help growers stay within their allocations and move the basin toward its sustainability targets, with far less economic disruption than fallowing.

The no-injury rule, enforced automatically

Every trade is screened against basin constraints, return flows, and seniority before it clears. The case-by-case review that normally takes months happens in the background.

Less administrative burden

Standardized, auditable transactions replace bilateral deals, legal review, and manual accounting. The platform integrates with your existing allocation systems.

Price discovery for the basin

A continuous order book and periodic call auction surface a real, visible price for water, instead of figures known only to a handful of brokers.

A transparent, tamper-proof record

Every allocation, trade, and constraint check is written to a shared ledger and remains auditable by the district and its stakeholders.

A shadow-market pilot, no risk

Run it on live allocations, prices, and constraints, with no binding transfers and no money moving. See how the market performs with your growers before anything binds.

For growers, Hydraux turns water you would have left idle into something you can sell, and gives you a fast, fair way to buy when you are short, all in the units you already hold.

Get paid for water you won’t use

Sell the share of your allocation you will not need this season instead of leaving its value on the table.

Secure water when you’re short

Buy what you need to carry a crop through a dry year, without a drawn-out one-on-one negotiation.

A real price, in the open

See what water actually trades for in your basin, instead of guessing or taking a broker’s word for it.

No middlemen, no months of waiting

Post an order and let the market find your counterparty and clear the trade.

Protected by design

Every trade is checked against the basin, so a deal can never quietly take water you depend on.

Your allocation, your call

Trade in the units you already hold. Nothing new to learn, and you decide what to buy and what to sell.


Where we start, where we're going

Groundwater first. Surface water next. Then the world.

We start with California groundwater. Under the state's groundwater law, agencies are setting hard pumping limits and, for the first time, giving growers defined, measurable allocations. Satellite measurement of water use is already in place, and groundwater prices stay far steadier than the wild swings of surface water. That makes it the natural place to start.

Starting here

Groundwater

California basins where allocations and measurement already exist. Where we begin.

Next

Surface water

The older, more tangled system of rivers and canals, where the same engine extends to harder trades.

The vision

Global water

Stressed basins worldwide, most without any market infrastructure.

Where we are

Testing the mechanism before anything binds.

Hydraux is in early pilot development. The first version is a shadow market: it runs on live allocations, prices, and the basin's actual constraints, but no money or water changes hands, so a district can watch it work before committing to it. The market and its constraint engine are already built as a working prototype, and pilot conversations are underway with California water districts.


Who's building it

Built at the meeting point of economics, technology, and water.

Hydraux is the work of Bilen Essayas, an economist trained at Stanford in market design and data science, with a background investing in growth-stage fintech and enterprise software.

The idea traces back to two years in a water-market-design research group at the Stanford Doerr School of Sustainability, working on how to share scarce water across the American West. Bilen builds from first principles and across disciplines, combining economics, technology, and a creative, design-driven instinct. Hydraux is where that combination goes to work on one of the hardest allocation problems there is.