Hold the Flood — The Head-works

CAM101 · r1 · 2026-09-06 · Campaign and District Designer · In review; proposal. Nothing here is an owner approval or tested behaviour.

District 7, the last, of the seven recommended on Districts. The Head-works is the World designer's example district (World and Mystery 7699de), placed in the lead's campaign (DES104 §2) and marked "Sketch — not designed" in that page's coverage table. This page writes its ground, its approaches, its decision and its consequences to the standard of DES104 §3.

What this page deliberately does not do: it does not answer the campaign's question. The World designer holds two candidate answers for the owner and the lead recommends one in DES104 §10.7. This page is built so that either answer can be dropped into it without redesigning the district, and §7 says exactly what each answer costs here. That is my job as the place's designer; choosing between them is not.

Sources: Campaign / DES104 r1 (§1–§2, §3.3 for the Barrier's dry dock, §4 modules and roles, §5 the boat's range, §6 the mystery thread, §7 coverage, §10 decisions) · World and Mystery 7699de (the campaign question, the six-part contribution rule, the fixed contract, the head-works sketch, the two answers) · Design Document ec1b6c §3–§4, §11 (the relay room's shut / fix / hold, which this district is the scaled version of) · Design Review 80a882 REV104-1, REV104-4, and the open note that the head-works' clue has no second form · Expansion Brief cdc0c5. Neighbours: Districts · The Collector · Pumping District · Design Index · Glossary.

1. The problem

Every district so far has let the player set where the Flood goes, which district can be read, or how much of it arrives. The head-works is the only place that sets how often, and it sets it everywhere at once and permanently.

That is the whole design problem of a finale in this game: it must be the same kind of decision the player already made in the relay room on expedition ten or eleven, at a scale where they can see it land on every district they have learned. It must not be a new machine, a boss, or a key. It is the relay's lever with more positions and a city on the other end.

The second problem is that the player arrives here having permanently changed four or five districts already, in a state of their own making. The head-works must read differently depending on what they did, or the campaign's persistence was decoration. §5 is how.

2. The ground, and two ways in

                          THE RESERVOIR  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                                 |                                  |
                            THE WEIR  ═══════════════════════   spill channel
              (boat route arrives here, from below)                 |
                                 |                                  |
            ┌── RACE HEADS ──────┴─────────────────────┐            |
            |     four gates, one per race, hand-worked|            |
            |                                          |            |
   THE GOVERNOR GALLERY  (dry, raised)  ── THE TALLY ROOM (optional; §6)
            |    the governor: the brake, the cadence lever, the district clutches
            |
   (race route arrives here, from the side, up the Collector's head race)
            |
   ══ MAINTENANCE WALK ══ down to the LANDING (colony-held dock; a shelter)
            |
   BEACON h1 (weir end)      BEACON h2 (gallery end)      PANEL: h1 / h2 / Off
   SLUICE-EQUIVALENT: the spill channel, where the Flood comes in with the overflow

The reservoir and the weir. Still water above, flowing water below: the races that turn every district's drum start here. The weir is the one place in the campaign where the player stands between a still body and a flowing one, and the distinction the whole rule set rests on — flowing water turns drums and carries no charge — is visible in a single view.
The race heads. Four hand-worked gates, one per race. They are not the finale's decision; they are the local puzzle (§3).
The governor gallery. Dry, raised, and the only dry ground in the district. The governor stands in it: a brake, a cadence lever with more positions than any panel, and district clutches on the shaft.
The tally room. Optional; §6.
Two fixed beacons and a three-position panel, on this district's own circuit, permitted by the trunk exactly as everywhere else — with one consequence the player will notice: this district's own dispatch is set by the lever they are standing next to.

Two ways in, either sufficient.

The boat route (DES104 §5): the colony's boat range, unlocked from the Tidal Barrier's dry dock, which requires shutting the barrier gates. Arrives at the weir, from below and wet. The approach is a conduction problem — the reservoir's water is the first thing met and everything the player knows about joined bodies applies.
The race route (mine; see The Collector §7): up the Collector's head race, walkable only while that district is held at level 0 — every gate open, nothing accumulating. Arrives in the gallery, from the side and dry. The approach is a timing problem — the race floods behind each dispatch, so the window is between them.

Why two. A player who bounced off the Barrier is not locked out of the finale, and neither is one who never mastered the Collector; the structural redundancy WLD103 rule 5 asks of clues holds for the road too; and the second approach is the best piece of optional content in the campaign, because it shows the half of the district the first route did not.

3. The local machinery problem: reaching the gallery

The gallery is dry and raised, and the governor is in it. Getting to the governor is the district's own puzzle and it is deliberately a recombination, not a new machine: the gallery door is a device on the gallery's line, and the gallery's line is fed from whichever race is running.

Four races, four gates. Closing a race's gate stops that race, and with it the drum it drives in the district downstream — the drain-valve R lesson from the pumping district's relay room, at four times the size.
The gallery's line runs off the race the player leaves open. So the door opens, but which race is running decides which of the district's two beacons is live and therefore where every crowd in the district walks while the player works.
The decision. Leave the weir race open and the gallery door opens with h1 live: the crowd holds at the weir, across the route the boat route arrived by. Leave the spill race open and h2 is live: the crowd holds at the gallery end — where the player is going. Close all four and the door is dead, but nothing is lit anywhere and the crowd spreads through a district with two dry approaches and no lure at all.

There is no free option. The player is choosing which of their two ways out to give away, which is the pumping district's price of the panel with the stakes made literal, and it is the last time the campaign asks that question before it asks the big one.

4. The decision: three positions, and what each does

The governor is the relay room's shut / fix / hold at city scale. Each is one interaction; none consumes salvage; the cost was getting here.

Position	The action	What it does, stated as a rule	What it costs
Slow (the cadence lever)	Wind the cadence lever back	Every district's trunk cadence lengthens permanently: fewer dispatches per expedition, each larger, everywhere. The forecast still works; the schedule the player has learned everywhere is rewritten at once	Larger surges are harder to route and harder to outlast; a district whose beats the player had memorised is now a different district. Every existing crowd-timing plan is spent
Stop (the brake)	Set the brake on the shaft	The trunk carries no time at all. Every district enters the shut regime permanently: no dispatches, no forecast, the Flood arriving by each district's own sluice as unannounced trickles that grow	The whole forecast layer of the game is gone, in every district, for good — including the colony's board and the Exchange's bank, which now sets nothing. Under the World designer's Answer A this also stops what feeds the grid, and §7 states what that means
Keep (the district clutches)	Leave the shaft running and set the clutches yourself	The player becomes the thing upstream that keeps time. Which districts are permitted, and at what cadence, becomes a standing setting readable and re-settable — from here, at the cost of a trip	Someone has to come back. The campaign's question is answered by the player taking the job, and the refuge's safety now depends on a setting only they maintain

Why these three and not a boss. They are the same three shapes the player already chose between in the relay room — stop it, fix it, leave it — which means the finale is legible to a player who has been paying attention and needs no tutorial at the worst possible moment. And they are genuinely different games afterward, which is what the pumping district's endings table already promises at district scale.

Deferral. The choice can be deferred, exactly as the relay's can. Reaching the gallery and leaving without touching the governor is a complete expedition, and the district stays open.

5. What the player's own campaign has already done to this district

The head-works reads differently depending on the state the player arrives in, and this is where the campaign's persistence pays off rather than merely accumulating.

Arriving by boat means the Tidal Barrier's gates are shut, which starves the Collector. Fewer organisms are in circulation, so the head-works' own surges are thinner and the weir approach is survivable — and the race route is submerged, because a starved Collector holds nothing and its head race runs full.
Arriving by race means the Collector is open and running, so the city is at full supply and the head-works' surges are at their largest — and the weir approach is the one that is easy, because the reservoir is drawn down.
A district darkened at the Exchange cannot be read from the gallery: the governor's board shows a position with no cadence on it, which is the last and clearest statement of what the bank has been doing all campaign.
The pumping district's relay, if the player shut it on expedition eleven, shows here as a clutch that is already disengaged — the first thing they ever did to the network, seen from the place that owns it. That costs no content at all and it is the single best moment I can offer this district.

6. Discovery

Local question: who oiled this? Every machine in the campaign is seized, silted, weathered or dead. The governor is not.

Notice. Fresh grease on the governor's shaft. A tally board in the gallery with a recent date. A cadence set to positions no evacuation would ever need.
Compare. The player has been reading tally boards since the pump hall. Every other one stops at the evacuation. This one does not.
Infer. The network is maintained, not merely running. That is the answer to the campaign question's second half — and for whom — in the only form this district can honestly give it before the owner has chosen between the two candidate answers.
Act. The governor, §4.
Recovery if missed. The grease and the board are in the gallery, which is the only way to the governor, so a player who is only trying to finish the game walks past both.

The redundant form, which REV104 records as missing and which I owe as this district's designer. My proposal, for the World designer to accept or replace: the Lock Flight's lock levers are greased and free, while every other hand-worked mechanism in the city is seized. The player has been pulling those levers since district two without a thought, because a lever that works is not evidence of anything until you have seen a city where nothing else does. It costs no asset, no room and no new interaction, and it pays off five districts later. If the World designer prefers a different second form, this district loses nothing by taking theirs.

The optional tally room. A room off the gallery, never required, holding the maintenance boards for the whole network: which district was serviced, when, and in what order. It is where a player who wants the campaign's bookkeeping can have it, and it is the natural home for whichever of the two candidate answers the owner chooses. Its contents are the World designer's to write.

7. What each candidate answer costs this district

Stated so that the decision in DES104 §10.7 can be made with its consequences visible. I do not recommend between them; that is the World designer's and the owner's.

Answer A, the machine. Costs this district nothing new. The grease is the works' own automatic maintenance, the tally room's boards are printed by the machine, and Stop darkens every powered door and pump in the city including the colony's — which makes the finale's cost enormous and entirely mechanical. It also settles REV104-4: the districts' circuits are fed by charge harvested from the Flood, which the Collector's meters have been telling the player for two districts.
Answer B, the keepers. Costs this district one human presence and a reason — an asset category this design has otherwise avoided completely, and the campaign's only character. It changes Keep from "the player takes the job" to "the player takes it from someone", which is a stronger scene and a different game. It leaves REV104-4 unanswered, so the grid's power source would need stating elsewhere.

The one thing I will say as the district's designer: whichever is chosen, the three governor positions in §4 stand unchanged. That is the property I built the district for.

8. Enemy and build pressure

Roles are the lead's four in DES104 §4. Everything below works with the walker alone.

The only district with still, flowing and absent water in one map, so it is the one place a loadout cannot be specialised. The coil works at the weir and in the spill channel and nowhere in the gallery; insulation matters below the weir and not above it. A player who has been carrying a district-specific rack all campaign has to build a general one for the first time, which is a fitting last exam and is a real, stated cost rather than a difficulty tint.
The gallery is the campaign's longest stationary interaction, because the governor's positions take time to set. That is what makes an enemy role that punishes standing still worth its cost here, and the lead's static — drawn to stored charge over a lit beacon — is exactly right for a player who arrived carrying batteries for the weir.
Floaters on the spill channel turn the spill race from scenery into a rule: flow overrides attraction while it runs, so opening the spill race sends whatever is in it away from the gallery, once.
What this asks of Combat: nothing new. Like the Collector, this district is an argument for the roles already proposed rather than for more of them.

9. Asset reuse and gaps

Reused: races, weirs, water planes and wet/dry tinting, drums and shafts, cable, lamps, beacons, a three-position panel, hand-worked gates, boards and tallies, walkway and gallery props, dock props, the humanoid mass.

Genuine gaps, marked and not filled. No free asset has been located, checked or licensed for any of these, and nothing here authorises creating one (Brief D009).

A large reservoir and dam exterior. The campaign's biggest single art ask, and the only district that cannot be dressed out of the pumping district's kit.
The governor as an oversized multi-position machine with per-district state readable at a glance. It is a panel, but it is the panel the whole campaign has been building toward, and dressing it as an ordinary one would undersell the ending.
Conditional, and attached to a decision the owner has not yet made: one human presence, if Answer B is chosen (§7).

A cheaper alternative, recorded now. If the reservoir exterior is out of reach, the district can be staged entirely inside the works — gallery, race heads and a weir seen through an opening — which keeps every decision in §3 and §4 and loses the one view the finale would most want. I would fight for the view and I would not fight for it at the cost of the district.

10. Open questions and dependencies

REV104-1 (World, ratified by Lead). The drum-and-trunk contract. §4's three positions all assume the drum makes the moment, the trunk permits it; Stop and Keep are meaningless without it. This is the single ruling this page most needs.
REV104-4 (Lead, with World). What supplies the districts' circuits. §7 records that Answer A settles it and Answer B does not, so this is coupled to a decision the owner is being asked to make.
World (WLD103). §6's redundant clue form; the tally room's contents; the campaign's answer. All proposals in their domain, and this district is built to survive their replacement.
Lead (DES104). Whether this page contradicts anything in the campaign page; if so, that page wins until agreed otherwise. Also §2's race route, which adds a second approach to the boat range in DES104 §5.
COL101. Keep makes the governor a standing colony setting, which is a persistent-progression object in Colony's domain rather than mine. If Colony would rather it were not, Keep can remain a one-time setting with no return trips, and the district still works.
Unresolved by me, honestly. Whether Slow is a real choice or a trap — rewriting a schedule the player spent ten hours learning may read as punishment rather than power, and I do not know. It is the position I would cut first if the three had to become two, and I am recording that now rather than defending it later.