The cash-flow waterfall and reserve accounts

0:00 Equity is always last

Here's something that surprises people new to project finance. A project can be earning healthy profits, and the sponsors can still receive nothing for a year or more. Not because anything's broken, but because the loan agreement says cash must flow through a strict order first, and a test along the way has failed. That order is the cash-flow waterfall, sometimes called the cascade. In this lecture you'll learn the typical order of payments in an operating period, what the debt service and maintenance reserve accounts do, how distribution lock-up tests work, what a cash sweep is, and how to model all of it so reviewers can follow it. By the end, you'll be able to run a period of cash through a waterfall by hand and explain exactly why equity did or didn't get paid.

0:59 Why it matters

Why does this matter? For lenders, the waterfall is protection: it keeps cash in the project precisely when it's most needed. For sponsors, it decides when they actually get paid, which drives equity IRR as much as the project's performance does. Lock-ups, sweeps and reserve funding can defer distributions significantly, so sponsors negotiate these terms hard and model them precisely. And for modellers, getting the order wrong isn't a small error. A model that pays equity before topping up a reserve will overstate returns and understate risk, and a model auditor will find it.

1:40 The concept: a typical operating waterfall

Here's a typical order in the operating period, though the exact sequence varies by deal. Revenue lands in the proceeds account. First, operating costs and taxes. Then senior lenders' fees and expenses. Then senior interest, along with any hedging payments. Then senior principal. Next, top up the debt service reserve account if it's below its required balance. Then the maintenance reserve account. Then any mezzanine or subordinated debt service. Then a cash sweep, if one has been triggered. And finally the lock-up test: if it passes, the remaining cash can be distributed to equity; if it fails, it's trapped in the project. Think of it like a set of champagne glasses stacked in a pyramid. You pour into the top, and the bottom glasses only fill once every glass above them is full. Equity is always the bottom glass.

2:40 Reserves, lock-ups and sweeps

The debt service reserve account covers debt service if CFADS temporarily falls short. It's often sized at the next six months of senior debt service, and can be funded in cash at financial close, as part of the uses, or with a bank letter of credit, which improves equity returns but costs fees. The maintenance reserve account smooths lumpy lifecycle costs. Distributions are usually permitted only if the historic, and sometimes projected, DSCR is above a lock-up level, perhaps one point one to one point two times depending on the deal, reserves are fully funded, and no default is continuing. If performance falls further, to a default level, lenders gain remedies. And a cash sweep uses some or all of the excess cash to prepay debt, either when triggered by poor performance or specific events, or to keep debt on a target profile.

3:42 Worked example one: a Dubai water SPV

Let's run one period, from the lesson, with illustrative numbers in millions of dollars. A fictional water treatment SPV in Dubai, semi-annual period. Revenue received: twelve. Operating costs and tax: four and a half. So CFADS is seven and a half. Senior interest: two point four. Senior principal: three point six. Total debt service: six. DSCR is seven and a half over six: one point two five times. The DSRA is already full, so nothing there. The MRA contribution is nought point four. Cash available after reserves: one point one. Now the lock-up test. The lock-up is one point one five times, and DSCR is one point two five. Pass. So one point one million goes to equity. Now change one number. If CFADS had been six point six, DSCR would be one point one times, below the lock-up. The nought point two left after the MRA would be trapped in the project, not distributed.

4:49 Worked example two: two periods, pass and fail

Now let's follow three periods, illustratively. Period one passes, as we just saw, and equity receives its distribution. In period two, a plant outage cuts revenue. CFADS falls, DSCR comes in at one point nought eight times, below the one point one five lock-up. Whatever cash remains after reserves isn't lost; it's held in the project's accounts. In period three, performance recovers, DSCR is back above the lock-up, reserves are full and there's no default. Depending on the loan agreement's terms, the trapped cash can then be released along with the current period's surplus. Two lessons. First, trapped cash is usually delayed, not destroyed, subject to the terms. Second, the timing still hurts equity returns, and if the loan agreement includes a sweep of trapped cash after a certain number of periods, it may go to lenders instead.

5:49 Watch me do it: a waterfall that reviewers can follow

Let me show you how I build the waterfall so anyone can follow it. Each payment line takes the lower of the cash available and the amount due, using MIN. Directly beneath it, a 'cash available after this item' row. So: CFADS, seven and a half. Interest paid: MIN of seven and a half and two point four. Cash after interest: five point one. Principal paid: MIN of five point one and three point six. Cash after principal: one point five. DSRA top-up: MIN of cash available and the shortfall to the required balance. And so on down to the lock-up test, which uses the DSCR, reserve balances and a default flag. If the test passes, distributions equal the cash available; otherwise, they're zero and the cash goes to a trapped-cash balance carried forward. Then checks: no line pays more than was available, and every dollar is accounted for.

6:54 Accounts, sponsors and common mistakes

In practice, lenders control a set of project accounts held with an account bank: proceeds, operating, debt service, reserves, distribution and compensation accounts. Transfers follow the waterfall, and that control is part of the lenders' security. The common mistakes: modelling distributions without lock-up tests; forgetting the initial DSRA funding in the uses at financial close; mis-ordering the waterfall compared with the loan agreement; and assuming trapped cash is lost, when it's usually released once tests are passed again, subject to terms. The discipline that prevents most of these is simple: build the waterfall line by line from the loan agreement's own wording, and cite the clause next to each row.

7:42 Recap and try this now

Let's recap. The cash-flow waterfall is the order in which project cash is applied, set out in the loan and accounts agreements: operating costs and taxes, senior debt service, reserve top-ups, subordinated debt, any sweep, and only then distributions, subject to a lock-up test. Reserves smooth shortfalls and lumpy costs; lock-ups keep cash in the project when cover is thin. Model it line by line with MIN and 'cash available after' rows, and add checks. Trace one period by hand: if you can't explain every line in plain language, neither can the model auditor. Your try-this-now: draw the waterfall for a real or hypothetical project, and run two periods through it: one that passes the lock-up test and one that fails.