How Desalination Projects Get Funded

Almost every other business plan starts with the market. A desalination plan should start with the money, because desalination is one of the few ventures where the funding structure is decided before the first membrane is bought. No lender or equity investor will look at a plant on the strength of a founder's savings. They look for a capital stack that matches how water infrastructure is financed everywhere from San Diego to the Gulf: a signed offtake, senior debt sized against the cost of water, and a subordinated or grant layer to make the numbers close.

The reference point in the United States is the EPA WIFIA programme. Water Infrastructure Finance and Innovation Act loans can finance up to 49% of eligible project cost, rising to 80% for communities of 25,000 people or fewer, and brackish and seawater desalination are explicitly eligible alongside aquifer recharge and water recycling. The 2025 funding round opened with $6.5 billion available. WIFIA does not replace your own capital; it de-risks the rest of the stack by sitting alongside cheaper senior debt.

The Carlsbad plant in San Diego County is the template every developer studies. Its roughly $1 billion build was financed with $734 million in tax-exempt bonds, and a later intake-and-wetlands upgrade added $160 million in California private activity bonds plus a $170 million WIFIA loan, saving ratepayers up to $54 million over the life of the loan (US EPA, 2025). The plant supplies about 10% of the county's water. That is the shape of a fundable desalination business: contracted revenue, public-private debt, and a clear public-benefit story.

The investor pitch, in one paragraph

Use this fill-in-the-blanks frame as the spine of your executive summary and your pitch to a project-finance desk. Every blank is a number your model must defend:

Fill every blank with a figure you can source, and you have the two-minute version of a bankable plan. The template below expands each of these into a full section, and our done-for-you services turn the frame into a lender-ready document with a five-year model behind it.

Who actually writes the cheque

It helps to be clear about which investor reads which part of the plan. A commercial bank or a project-finance desk cares about one thing above all: the debt service coverage ratio, the multiple by which contracted cash flow covers each year's interest and principal. Below about 1.2x they will not lend; above 1.35x they relax. An infrastructure fund or a sponsor taking equity cares about the project IRR and the tenor of the offtake, a 25-year water purchase agreement with a creditworthy municipality is worth far more to them than a higher headline price on a five-year deal. A grant panel or a WIFIA reviewer cares about eligibility, public benefit and creditworthiness in roughly equal measure. A plan that speaks to all three, in that order, is the one that closes. That is why the desalination template puts the capital stack and the offtake ahead of the technology, and why the financial model is the single most scrutinised deliverable in the package.

Market Size, Demand & Growth

Desalination is a large, structurally growing market driven by water scarcity rather than fashion, which is exactly what a cautious lender wants to see. Estimates differ by scope. Fortune Business Insights, 2025 puts the global desalination technologies market at $27.8 billion in 2025, growing at roughly 8.8% a year to 2034. Straits Research, 2025 tracks the water desalination market at $24.26 billion in 2025 with an 11.6% CAGR to 2033, while Mordor Intelligence sizes the narrower desalination-system market nearer $18 billion. The gap between these numbers is a scope question, not a disagreement about direction: every credible source has the market compounding at 8-12% annually.

Demand growth is concentrated where fresh water is scarcest and energy is cheapest, the Gulf, North Africa, southern California, Australia, and increasingly southern Europe. That geography matters for a business plan because the economics of a plant in Saudi Arabia, where Saline Water Conversion Corporation (SWCC) offtake and low-cost power make water cheap to produce, are completely different from a plant in a temperate market where local surface water is already cheap.

The competitive picture at the top of the market is dominated by a handful of engineering and operating groups. Veolia runs more than 500 desalination plants across 70-plus countries and recently won a $320 million UAE contract. Acciona Agua, IDE Technologies, Doosan Enerbility and SWCC lead on large seawater RO and thermal builds, while ACWA Power develops build-own-operate desalination concessions across a dozen countries in the Middle East, Africa and Southeast Asia. A new entrant does not compete with these firms head-on; it wins a specific offtake, an industrial site, a resort island, a municipality, that is too small or too local for a global EPC to chase. Your plan's job is to prove you own that niche.

Two structural trends give a smaller developer room to operate. The first is decentralisation: as membrane and pump costs fall, sub-utility plants of 2,000 to 20,000 m³/day are becoming economic for single industrial buyers such as mines, power stations, food processors and, increasingly, data centres that need cooling water. These buyers want a contracted supply from a nimble operator, not a national tender. The second is renewable pairing. Solar and wind can now push the levelised cost of desalinated water below $0.70 per cubic metre in the right location, and a plan that credibly integrates renewable power carries both a cost story and a sustainability story that grant panels reward. Neither trend removes the need for a signed offtake, but both widen the set of offtakers a first-time developer can realistically win.

What It Costs to Build a Desalination Plant

Capital cost scales almost linearly with capacity, so quote it per unit of output rather than as a single headline number. The industry rule of thumb for utility-scale seawater reverse osmosis is around $4,000 per cubic metre per day of nameplate capacity. On that basis a 10 million gallon per day (about 38,000 m³/day) plant runs $30-50 million. Below utility scale, small brackish or containerised units start in the tens of thousands to low millions; mid-range projects sit at $60-300 million; and large coastal facilities exceed $300 million (Genesis Water Technologies, 2025).

What surprises first-time developers is where the money goes. The membranes and pumps that make desalination sound expensive are not the biggest line. Civil works, the intake, the outfall, on-site piping, tanks and buildings, dominate the budget.

Capital Cost Breakdown (share of CAPEX)

• Civil works (intake, outfall, tanks, buildings): 30–40%, the largest single line, and the one most exposed to site conditions
• RO process equipment (membranes, high-pressure pumps, energy recovery devices): 20–30%
• Construction labour: 15–20%
• Electrical works (switchgear, transformers, control panels): 10–15%
• Marine survey, environmental impact assessment, permitting & development: 3–8%, spent before you can break ground

Energy recovery devices deserve a line of their own in the plan because they change the operating economics. Isobaric devices such as the Energy Recovery PX series or Danfoss iSave recover pressure from the reject stream and cut specific energy use materially. Skimping on them lowers CAPEX and raises OPEX for 25 years, which is exactly the trade a lender will interrogate.

The costs incurred before you can break ground catch developers off guard because they are spent with no revenue in sight. A comprehensive marine survey and an environmental impact assessment are needed to prove the intake and brine outfall will not disrupt the local ecosystem, and the results can force a redesign of the very components that dominate the budget. Front-end engineering design, geotechnical work, and the legal cost of negotiating the water purchase agreement all fall in this pre-construction window. Budget 3-8% of total project cost here and, just as importantly, budget the time, this is the phase that most often blows a schedule. A plan that shows a realistic development budget and timeline reassures a lender far more than an optimistic one that assumes permits arrive on request.

Lean versus utility scale

The single most useful thing a founder can do early is decide honestly which end of the cost curve they are on. A lean launch, a containerised brackish RO unit for a single remote site, can be stood up for tens of thousands to a couple of million dollars, largely self-funded or asset-leased, and generates revenue within months. A planned utility build is a multi-year, multi-hundred-million-dollar project-finance exercise with a bond issue and years of permitting. Both are legitimate desalination businesses; they are simply different companies with different investors, and the plan must commit to one. Trying to hedge between them produces a document that convinces nobody.

Funding Routes

For a utility-scale plant the stack is project finance against a water purchase agreement, supported by tax-exempt private activity bonds and a WIFIA or State Revolving Fund layer, as described in the funding section above. For a smaller brackish or industrial-scale plant, US developers can use SBA 7(a) loans (up to $5 million) and equipment financing, and pair them with US Bureau of Reclamation or Department of Energy water-technology grants. In the UK the equivalent smaller-scale routes are Innovate UK grants for water-technology and, for a genuinely early venture, the British Business Bank Start Up Loans scheme (up to £25,000 per founder at 6% fixed). A desalination plan that shows the wrong funding route for its scale, merchant equity for a utility plant, or bond finance for a container unit, signals to a reviewer that the founder has not built one before.

Revenue Model & Water Economics

Revenue in desalination is deceptively simple, you sell water, and the whole plan lives or dies on two numbers: the price you sell at and the all-in cost to produce. Desalinated water typically sells for $0.60 to $1.90 per cubic metre depending on region and contract, almost always under a long-term water purchase agreement rather than on a spot market. Operating cost alone runs $0.50 to $1.50 per cubic metre, and the full levelised cost of water for a modern 10 MGD seawater RO plant sits below $1.00 per cubic metre when financed at 7-10% over 25 years (Thunder Said Energy).

Energy is the variable that decides everything. A seawater RO plant consumes 3.5-4.5 kWh per cubic metre of product water, and electricity is 35-46% of operating cost. That is why Lets Do Water reduces profitability to five local factors: energy price, local water price, plant scale, land and labour cost, and permitting friction. The same plant is a strong business in a high-water-price, cheap-power market and unviable in a market where surface water already sells below your production cost, the situation that has stalled several California proposals.

Worked example: a 20,000 m³/day plant

Suppose a 20,000 m³/day (about 5.3 MGD) seawater RO plant sells water at $1.20 per cubic metre under a 25-year offtake at 90% availability. Annual output is roughly 6.57 million cubic metres, producing about $7.9 million in year-one revenue. If the all-in production cost is $0.75 per cubic metre, the plant returns roughly $3.0 million in gross margin before debt service. Layer the capital stack on top, say $16 million total cost, funded 21% equity and 79% senior debt, and the plan's real question becomes whether that $3.0 million comfortably covers debt service and still leaves a project equity IRR a sponsor will accept, usually 8-14% for contracted offtake. Move the water price to $0.90 or the power price up 20% and that headroom disappears. The financial model is the deliverable investors actually read.

Secondary revenue

Water sales are the core, but the strongest plans show at least one adjacent stream. Some operators turn the brine reject into saleable products, sodium chloride and other minerals, under the banner of brine mining or zero-liquid-discharge. Others sell surplus capacity to industrial neighbours, or bundle operations-and-maintenance contracts for third-party plants. These streams rarely change the headline economics, but they signal to an investor that the founder understands the whole value chain, not just the membrane.

The operating cost stack that decides margin

Because revenue per cubic metre is fixed by the offtake, margin is won or lost on the cost side, and the plan should break operating cost into its real components rather than a single figure. Electricity is the largest at 35-46%, which is why energy procurement, a power purchase agreement, on-site solar, or a demand-response arrangement, is itself a commercial decision worth a paragraph. Membrane replacement is the second line most often forgotten: reverse-osmosis membranes last three to five years and cost 5-10% of annual operating expense to swap out, so a plant that has been running for four years faces a step-change in cash outflow that must sit in the model as a reserve. Chemicals for pre-treatment and cleaning, labour for a small team of operators and maintenance technicians, and periodic pump overhauls make up most of the rest. A five-year forecast that names each of these and flexes them against energy price and availability is the difference between a plan a lender funds and one they send back.

Three Desalination Business Models Compared

"Desalination business" covers three very different ventures with different capital needs, customers and risk. Your plan should state clearly which one you are building, because a reviewer who cannot tell will assume you do not know.

The mistake to avoid is writing a plan that borrows the market size of the utility segment, the margin story of the modular segment, and the funding language of neither. Pick a model, size the plant to a real offtaker, and let the rest of the plan follow from that choice. If you are weighing an adjacent water venture, our desalination template sits alongside plans for a water purification plant and a biological wastewater treatment operation, which share much of the same regulatory and capital structure.

Permits, Consents & Regulatory Approval

Desalination is regulated primarily through what you put back into the sea, not what you take out. Brine is the constraint, and the permitting timeline for it is long enough that it belongs in the plan's critical path, not a footnote. The concentrate stream is roughly twice the salinity of seawater, and regulators treat it as a pollutant discharge to be diluted, diffused and monitored rather than simply released. A plan that describes the outfall design, a diffuser to mix brine quickly with the receiving water, and monitoring to prove salinity stays inside its consent limits, signals to a permitting authority that the developer has done the engineering, and to a lender that the biggest environmental risk is under control.

United States

• NPDES discharge permit under the Clean Water Act, issued by the EPA or a delegated state agency, the core requirement for discharging brine to a water of the United States
• Brine salinity limits commonly set within ±2 parts per thousand of ambient receiving-water salinity, with acute and chronic toxicity testing (for example using inland silverside, Menidia beryllina) typically twice per year
• Marine survey and environmental impact assessment for intake and outfall siting, to protect the local ecosystem
• State and local approvals: coastal development permits, land use and zoning; in California, Ocean Plan amendments on intake and brine disposal are notably strict
• WIFIA eligibility is a financing step, not a licence, but it runs on its own letter-of-interest timeline that should be sequenced with permitting

United Kingdom

• Water abstraction licence from the Environment Agency, now moving into the Environmental Permitting Regulations regime
• Environmental permit for discharge of brine and process water, Thames Water holds both abstraction and discharge consents for its Beckton (Thames Gateway) plant
• Planning permission, which for Beckton was granted on appeal by the Secretary of State, with operation restricted to drought conditions under the drought management plan
• Drinking Water Inspectorate standards where the output enters public supply

Gulf & Other Jurisdictions

• In Saudi Arabia, offtake typically runs through Saline Water Conversion Corporation (SWCC) or the Water & Electricity Company, with plants delivered as build-own-operate concessions
• In the UAE, procurement is via independent water project (IWP) tenders of the type ACWA Power and Veolia contract into, with environmental approval for intake and brine
• Across the Gulf, the commercial structure, a long concession with a creditworthy offtaker, is itself the regulatory reality a plan must reflect

Five Mistakes That Kill Desalination Plans

These are the errors that get a desalination plan rejected by a project-finance desk or a grant panel. Each one is avoidable in the writing.

• Modelling CAPEX per gallon and ignoring energy. Energy is 35-46% of operating cost. A plan that quotes a build cost but does not stress-test power price has not modelled the business at all.
• Assuming merchant water sales. Water is not sold on a spot market. Without a signed or letter-of-intent water purchase agreement before financial close, the revenue line is a guess and the plant is unfundable.
• Under-budgeting permitting. The marine survey, environmental impact assessment and NPDES brine consent take months to well over a year. Treating them as a formality wrecks the schedule and the cash flow.
• Forgetting membrane replacement. RO membranes last 3-5 years and cost 5-10% of annual OPEX to replace. A model without a replacement reserve overstates margin for the whole forecast.
• Bringing the wrong capital stack. Presenting utility-scale plans on founder equity, or pitching a container unit with bond finance, tells the reviewer you have never closed a water project. Match the stack to the model.

Sample Business Plan Preview

Here is an extract from a desalination plan written by our team, so you can see the level of specificity investors and lenders expect. Notice what it leads with: not the technology, but the offtake, the price, the capital stack and the coverage ratio. That ordering is deliberate, and it is the single biggest difference between a plan that reads like a science project and one that reads like an investment.

What's in the Template

Every Avvale business plan template is pre-structured for its industry. For desalination, that means the sections a water-infrastructure lender and an equity investor actually score:

• Executive Summary: the plant, the offtake, the capital stack and the return, in one page built from the investor-pitch frame above
• Project & Technology Overview: capacity, seawater versus brackish RO, intake and outfall design, energy recovery approach
• Market & Water-Demand Analysis: regional scarcity, the case for the offtaker, and why alternative water sources cost more
• Offtake & Commercial Structure: the water purchase agreement, price, term, indexation and availability assumptions
• Regulatory & Permitting Plan: NPDES or Environment Agency consents, brine limits, environmental assessment timeline
• Operations Plan: staffing of operators and maintenance technicians, membrane replacement schedule, energy procurement
• Capital Stack & Funding: equity, senior debt, WIFIA/SRF or grant layer, sources and uses
• Management Team: engineering and development track record, the credibility a project lender underwrites

The optional Financial Forecast add-on (included in our $300/£250 and $1,000/£800 packages) provides a five-year Excel model with income statement, cash flow, balance sheet, levelised cost of water, debt service coverage, and a project equity IRR, the model a bank or grant panel reads before anything else. Start from the free business plan template if you want to draft it yourself, or hand the whole thing to our business plan writers.

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