DitchBook

How companies are matched to their ditches

Two state record systems that never shared a key — joined only where the state's own words make the answer certain.

The story starts with a list. Three beats. First, the Open Water Foundation's data file of Colorado ditch and reservoir companies, its table showing a Company column and a County column filled in and a third column headed Ditch WDID whose every cell reads, in faint italics, TO BE ADDED. An arrow leads to the second beat: the DitchBook census of 1,383 companies, refreshed monthly against the Secretary of State's register. A third arrow points down into the rest of the page, where the empty column gets filled. OPEN WATER FOUNDATION Colorado ditch & reservoir companies — by 2018 Company County Ditch WDID TO BE ADDED TO BE ADDED TO BE ADDED DITCHBOOK · 2026 The seed, re-verified 1,383 companies refreshed monthly against the Secretary of State's register and the penciled-in column finally filled
The list came first. The column for each company's structure numbers came with it — empty, waiting. Scroll sideways to see the whole drawing.

By 2018, the Open Water Foundation — a Colorado nonprofit — had assembled the first public list of Colorado's ditch and reservoir companies, and penciled in a column it hoped to fill one day: each company's structure IDs. DitchBook is built on that seed, with credit, here and on our methods page. This page is the story of how the column got filled.

Where the state watches water. A simple landscape. A river runs down the left. On its bank stands a headgate — a gate in a concrete frame with a lift wheel — and a ditch runs right from it, feeding three small fields through short laterals. On a rise to the right, a reservoir is held back by a dam, whose outlet runs down to the same ditch. Two license-plate tags hang above the drawing, one pointing to the headgate reading WDID 0500526 DITCH, one pointing to the dam reading WDID RESERVOIR. river ditch fields reservoir WDID 0500526 · DITCH WDID · RESERVOIR
The state tracks water at the points where it is controlled. Each point gets an ID — a WDID — like a license plate, plus a type label. Scroll sideways to see the whole drawing.

Words on this page

Secretary of State
the state office where every Colorado company is registered
Division of Water Resources (DWR)
the state agency that runs the rivers — it decides who may take water, and when
Entity ID
a company's registration number with the Secretary of State
Water right
what the state recognizes a company may take, with a date that fixes its place in line
The census
the list of Colorado ditch and reservoir companies this site keeps

1 The two records

Two filing cabinets that never shared a drawer. Two filing cabinets stand side by side with a gap between them. The left is labelled Colorado Secretary of State and holds a record card giving a company's legal name, standing and registered agent, keyed by an entity number. The right is labelled Colorado Division of Water Resources and holds a record card giving a structure's type, county and operator, keyed by a WDID. Between them a dashed line and a cross mark the gap: the two cabinets share no key. COLORADO SECRETARY OF STATE Legal name of the company Standing · registered agent entity 19871000986 COLORADO DIVISION OF WATER RESOURCES Structure type · county Who operates it WDID 0500526 no shared key
Each cabinet has its own key. Nothing in one points at the other — which is why the join has to be made out of the one thing both records hold in common: the company's name. Scroll sideways to see the whole drawing.
The who

Colorado Secretary of State — business registry

1,383 companies: exact legal name, entity ID, standing — whether the company is current with the state — and registered agent, the person the state lists to receive legal mail. Refreshed monthly.

The what

Colorado Division of Water Resources — structure records

The state tracks water at the points where it is controlled — a ditch's headgate, a reservoir's dam. Each of those points is a structure, and each one gets an ID number called a WDID, plus a type label (ditch, reservoir, well). Each record also carries the state's own associated-contacts entry: the line where DWR writes down who operates the structure.

2 The key

The match test: two records that say the same name. Two record cards side by side. The left, from the Colorado Secretary of State, gives the registration number entity 19871000986 and the company name HIGHLAND DITCH COMPANY, highlighted. The right, from the Colorado Division of Water Resources, gives structure 0500526 of type DITCH and the operator name HIGHLAND DITCH COMPANY, highlighted on the same line. A bracket joins the two highlighted names across the gap, with a check mark at its centre. COLORADO SECRETARY OF STATE entity 19871000986 REGISTRATION NUMBER HIGHLAND DITCH COMPANY in good standing STATUS COLORADO DIVISION OF WATER RESOURCES structure 0500526 · type: DITCH STRUCTURE RECORD HIGHLAND DITCH COMPANY one county WHERE IT SITS the same words, letter for letter
The join is made of the state's own words, not our guess: the operator name on the water record has to equal the registered legal name exactly. Scroll sideways to see the whole drawing.

The match test: the state's words, not our guess

DWR's contact name for the structure must equal the company's legal name exactly, after mechanical cleanup only (capitals, punctuation, “Co.”/“Company”). No fuzzy matching is ever published — nothing is joined because it looked close enough.

3 Three guards

The three guards, drawn as a funnel. A funnel. Every candidate pairing enters the wide mouth at the top. It narrows through three bands in turn: guard one, one company only; guard two, geography must agree; guard three, the right kind of structure. A dashed chute leaves each band sideways and drops into a hatched tray labelled the not-yet pile. Beside guard three, three chips read DITCH with a check, RESERVOIR with a check, and WELL set aside. What survives all three guards leaves the narrow spout at the bottom into a solid navy box marked published. every candidate pairing 1 One company only 2 Geography must agree 3 The right kind of structure published the not-yet pile DITCH RESERVOIR WELL — set aside
Anything a guard stops is not thrown away — it goes on the not-yet pile and waits for a record clear enough to settle it. Scroll sideways to see the whole drawing.

One company only

The name must map to exactly one registered company. Generic ditch names exist in many counties; when two companies could claim the same name, both candidates are set aside.

Name collision → set aside

Geography must agree

The structures must sit where the company operates. Scattered counties are the signature of a shared name gluing unrelated ditches together.

Scattered → set aside

The right kind of structure

Ditches and reservoirs only. This guard exists because our own audit caught a company about to be credited with a well's 1904 water right through a secondary contact listing.

Wrong type → set aside

4 The human gate

156 of the published matches were additionally verified one at a time by hand — including 12 companies whose systems genuinely cross county lines, each checked against the state record before publishing. Anything still ambiguous is excluded rather than guessed.

5 What gets published

Published: 301 companies matched to 540 structures

Every row links to the state's own record — anyone can check any match in one click. When a later check finds a problem, the match is retracted publicly: 3 retractions to date, held in place by a public do-not-republish list built into the code, so a withdrawn claim cannot quietly return.

Follow one match through

Highland Ditch Company — the Secretary of State registers HIGHLAND DITCH COMPANY (entity 19871000986). DWR's record for structure 0500526 names its contact: HIGHLAND DITCH COMPANY. One company, one county, a ditch. Published — with the state's record linked.

The matches we don't publish (yet)

The two piles, drawn to scale. One bar stands for all 1,383 companies on the list. A solid navy block on the left, about a fifth of the bar, is the 301 companies with a published structure match. The much longer hatched block to its right is the 1,082 companies with no published match yet. 301 published matches we can prove 1,082 no published match yet the not-yet pile 1,383 companies on the list
Drawn to scale, so the shape of the honest answer is visible: we publish the smaller pile — the one the record settles. Scroll sideways to see the whole drawing.

About 1,082 companies in the census have no published structure match. These are the hard cases — names shared by ditches in several counties, systems known by old names, structures operated jointly, records that disagree. Historically, questions like these were answered one at a time by engineers and water attorneys. We'd rather say “not yet” than guess.

When the record itself resolves a case, it moves: Jackson Ditch Company published only after DWR's own record of the other names that ditch has gone by, and the state's 2005 map of the land each ditch serves, independently confirmed the name. If you run one of these companies, you can help us confirm the record — every company page has a claim link.

Sources: Colorado Secretary of State business-entity data (standings as of July 23, 2026) and Colorado DWR structure and water-rights records (pulled July 11, 2026). Figures on this page are computed in the same build that publishes the pages they describe. The full written method, including what we refuse to publish and why, is on the methods page.