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Switch site 35 sites · 10 basins2 states Group by
OH Ohio 34
BOSC BOSC Lima Ottawa River · Lima, OH Building Under construction #1261 URB Urbana Mad River · Great Miami Live Investigating #1263 DEF Defiance Maumee mainstem Queued Investigating #1264 FIN Findlay Blanchard River Queued Investigating #1265 TOL Toledo Lucas Co WRRF Queued Investigating #1266 VWT Van Wert Town Creek · Little Auglaize Queued Investigating #1267 BRY Bryan Prairie Creek · Tiffin River Queued Investigating #1268 OTW Ottawa Blanchard River (lower) Queued Investigating #1269 SPR Springfield Mad River · Great Miami Queued Investigating #1270 XEN Xenia Little Miami Queued Investigating #1271 WPA Dayton · WPAFB Mad River · Great Miami Queued Investigating #1272 HAM Hamilton · Middletown Great Miami (lower) Queued Investigating #1273 TRP Troy · Piqua Great Miami (upper) Queued Investigating #1274 SID Sidney Great Miami · headwaters Queued Investigating #1275 GRV Greenville · Darke Co Stillwater · basin divide Queued Investigating #1276 WIL Wilmington Todd Fork · Little Miami Queued Investigating #1277 WUN West Union · Adams Co Ohio Brush Creek · Ohio River Queued Investigating #1278 NAL New Albany · Licking Scioto ↔ Muskingum divide Tracking Investigating #1279 COL Columbus Scioto · Olentangy Tracking Investigating #1280 CSH Coshocton Tuscarawas + Walhonding Tracking Investigating #1281 PIK Piketon Scioto River · PORTS Tracking Investigating #1282 SAN Sandusky · Perkins Twp Sandusky Bay · Lake Erie Tracking Investigating #1283 NWK Newark Licking River Tracking Investigating #1284 ZAN Zanesville Muskingum mainstem Tracking Investigating #1285 FRE Fremont · Clyde Lower Sandusky Tracking Investigating #1286 TIF Tiffin Sandusky (mid) Tracking Investigating #1287 BUC Bucyrus Sandusky headwaters Tracking Investigating #1288 CLE Cleveland Lower Cuyahoga Tracking Investigating #1289 AKR Akron Upper Cuyahoga · CVNP Tracking Investigating #1290 LRD Lordstown · Warren Upper Mahoning Tracking Investigating #1291 YNG Youngstown Mahoning mainstem Tracking Investigating #1292 LAN Lancaster Upper Hocking Tracking Investigating #1293 ATH Athens Lower Hocking Tracking Investigating #1294 LOG Logan Hocking Hills Tracking Investigating #1295
MAU Maumee Basin 8 sites
2MI The Two Miamis 9 sites
SE Southeastern Basins 10 sites
NE Northeast Basins 8 sites
Each site is a section of the Watermark platform — pivoted by basinstate. Live & building sites open; queued and tracking sites route to their coming-soon / watch page.
Switch site 35 sites · 10 basins2 states 35 open Group by

Each site is one Watermark investigation. The page color says what opens; the campus line is the build on the ground — two different clocks.

OH Ohio 34
BOSC BOSC Lima Ottawa River · Lima, OH Draft Under construction #1261 URB Urbana Mad River · Great Miami Open Investigating #1263 DEF Defiance Maumee mainstem Queued Investigating #1264 FIN Findlay Blanchard River Queued Investigating #1265 TOL Toledo Lucas Co WRRF Queued Investigating #1266 VWT Van Wert Town Creek · Little Auglaize Queued Investigating #1267 BRY Bryan Prairie Creek · Tiffin River Queued Investigating #1268 OTW Ottawa Blanchard River (lower) Queued Investigating #1269 SPR Springfield Mad River · Great Miami Queued Investigating #1270 XEN Xenia Little Miami Queued Investigating #1271 WPA Dayton · WPAFB Mad River · Great Miami Queued Investigating #1272 HAM Hamilton · Middletown Great Miami (lower) Queued Investigating #1273 TRP Troy · Piqua Great Miami (upper) Queued Investigating #1274 SID Sidney Great Miami · headwaters Queued Investigating #1275 GRV Greenville · Darke Co Stillwater · basin divide Queued Investigating #1276 WIL Wilmington Todd Fork · Little Miami Queued Investigating #1277 WUN West Union · Adams Co Ohio Brush Creek · Ohio River Queued Investigating #1278 NAL New Albany · Licking Scioto ↔ Muskingum divide Watching Investigating #1279 COL Columbus Scioto · Olentangy Watching Investigating #1280 CSH Coshocton Tuscarawas + Walhonding Watching Investigating #1281 PIK Piketon Scioto River · PORTS Watching Investigating #1282 SAN Sandusky · Perkins Twp Sandusky Bay · Lake Erie Watching Investigating #1283 NWK Newark Licking River Watching Investigating #1284 ZAN Zanesville Muskingum mainstem Watching Investigating #1285 FRE Fremont · Clyde Lower Sandusky Watching Investigating #1286 TIF Tiffin Sandusky (mid) Watching Investigating #1287 BUC Bucyrus Sandusky headwaters Watching Investigating #1288 CLE Cleveland Lower Cuyahoga Watching Investigating #1289 AKR Akron Upper Cuyahoga · CVNP Watching Investigating #1290 LRD Lordstown · Warren Upper Mahoning Watching Investigating #1291 YNG Youngstown Mahoning mainstem Watching Investigating #1292 LAN Lancaster Upper Hocking Watching Investigating #1293 ATH Athens Lower Hocking Watching Investigating #1294 LOG Logan Hocking Hills Watching Investigating #1295
MAU Maumee Basin 8 sites
2MI The Two Miamis 9 sites
SE Southeastern Basins 10 sites
NE Northeast Basins 8 sites
The page — what opens on Watermark Open · Draftfull record Queued · Watchingpreview page Restrictedrequest access
The campus — the build on the ground Investigating Confirmed Under construction Operational

← About

Privacy policy

Read without being watched.

Watermark is a static, public-record site. Reading it takes no account, sets no cookies, and runs no analytics or advertising trackers — every page reads with JavaScript off. This page states that plainly, and gives an honest account of the few places where using the site does touch your data.

This describes the current build. Some surfaces below — accounts, email digests — ship behind a switch and may not be live in this pre-launch site yet; when they are, this is how they behave.

Reading anonymously

The site is a set of static files served from Cloudflare Pages. Reading any page — a record, a document, a report — requires no login and stores nothing on your device for us. There are no advertising trackers, no analytics cookies, and no third-party tags, and no page depends on JavaScript to be read.

Two small exceptions, both first-party and neither identifying you:

  • Edge logs. Like any web host, Cloudflare processes your IP address and request in transit to serve the page and block abuse. We use it transiently for rate-limiting the interactive endpoints below; we don't build a profile from it.
  • Performance telemetry (optional). When enabled, the browser may send an anonymous beacon of page-load timings (Core Web Vitals) and JavaScript errors to our monitoring backend (Honeycomb) so we can keep the site fast and unbroken. It carries no account, no name, and no reading history — just the technical shape of the page load.

Interactive forms (Ask, Submit) use Cloudflare Turnstile, a privacy-preserving alternative to CAPTCHA that verifies you're not a bot without the cross-site tracking a conventional CAPTCHA does.

When you ask the corpus

Ask the corpus answers a question using only the extracted record. When you submit a question, the text of that question is sent to Anthropic's API to generate a cited answer from the retrieved sources, and your IP is used transiently to rate-limit the endpoint. Your question isn't tied to an account and isn't kept as a profile of you. Don't paste anything private into it — treat it like a public search box.

When you submit a tip or correction

Submitting a tip, document, or correction proposes an entry to a public case file: what you type is used to open a labeled issue on our public GitHub repository. Please don't put anything you wouldn't want on the public record into the body of a submission.

  • Optional contact. If you choose to leave a way to reach you, it's held in a private channel keyed to your submission — never written to the public issue — and is kept only briefly before it expires.
  • Attachments. Files you upload are stored to support the submission and referenced from it.
  • Your IP is used transiently to rate-limit the endpoint and, with Turnstile, to keep out spam. Sources are never named without consent.

If you create an account

An account is entirely optional — nothing on the reading side requires one. If you do sign up, identity is handled by AWS Cognito, which holds your email address, a verified-email flag, and a stable user identifier. Sign-in uses a standard authorization-code flow; your session's refresh token is kept in an HttpOnly, Secure cookie that scripts on the page cannot read.

Your preferences live in our own database (Lakebase) under a user_prefs record keyed to your account:

  • an optional display name;
  • notification preferences — which sites and categories you follow, and how often;
  • your digest opt-in state.

Your email is used only to send the digests and notifications you opt into. Every such email carries a one-click unsubscribe that works from a signed link without logging in, and you can change or clear these preferences any time from your account.

What we never do

We do not sell, rent, or trade your data. We don't run advertising, we don't share your information with ad networks or data brokers, and we don't track you across other sites. The record is funded by contributions, not by your data.

Access, correction & deletion

You can reach the record team through the submission form for any privacy request — to see what's associated with your account, correct it, or have it deleted. Deleting your account removes your stored preferences; an optional contact left with a submission expires on its own. Corrections to the record itself run through the same correction path, published with a provenance note.

Last updated 8 July 2026