Waterpark Simulator saves are stored in the Windows folder CayPlay publishes in its pinned support post:
%userprofile%\AppData\LocalLow\CayPlay\WaterparkSimulator\slots
Open it with Win + R, paste the path, and press Enter. A park uses an .es3 save, and CayPlay says the folder can contain up to ten .bac backups such as .bac1, .bac2, and .bac3.
Copy the entire slots folder first
Close the game before working with save files. In File Explorer, copy the complete slots folder to a separate safe location. Give the copy a date and keep the original untouched.
Do not rename files in the only copy. A failed recovery attempt should be reversible by returning to the preserved folder.
If Steam Cloud is enabled, remember that Cloud listing does not replace a manual recovery copy. Avoid launching repeatedly while changing files because synchronization can make the state harder to understand.
Identify the park and backups
Look for the park’s .es3 file and files that continue with .bac, .bac1, .bac2, and similar suffixes. CayPlay says there may be up to ten backup candidates.
Work on a copy of one candidate. Keep a note of its original filename so you can return it exactly. Do not rename every backup at once; multiple files with the same target name create ambiguity.
Windows may hide known extensions. Enable filename extensions in File Explorer so you can see whether the final file truly ends in .es3 rather than an accidental extra suffix.
Restore one backup candidate
CayPlay’s example is park.es3.bac1 renamed to park.es3. Perform that change on the copied candidate in the test folder, not on the untouched archive.
Windows will warn that changing a file extension can make the file unusable. CayPlay says to accept that warning for this recovery procedure.
Ensure the resulting filename has no spaces. The developer gives park_2.es3 and park2.es3 as recognizable examples and warns that park 2.es3 will not be seen by the game.
Place only the intended recovered .es3 in the live slot position, keeping the original archive elsewhere. Launch the game and check whether the park appears and loads.
Move through backups carefully
If the first candidate is not recognized or loads in a damaged state, close the game. Restore the live folder from your untouched copy, then test the next backup candidate using the same one-at-a-time process.
Do not overwrite the archive with a failed converted file. Each attempt should begin from known originals.
When a recovered park loads, save normally under the game’s supported interface, exit, and verify that it loads again. Keep the pre-recovery archive until you have played enough to trust the result.
Avoid common filename errors
The target must end in .es3, not .es3.bac1, .es3.txt, or .es3.es3. Visible extensions make this easier to check.
Remove spaces from the park filename. Preserve underscores or a continuous name as CayPlay recommends.
Do not alter the file contents in a text editor. Recovery is a filename operation on an existing backup, not manual save editing.
Do not mix files from an unrelated same-name game. This guide applies only to CayPlay’s Waterpark Simulator base game, Steam AppID 3293260.
Understand Steam Cloud and manual copies
The Steam store lists Steam Cloud for the base game. That means Steam provides a synchronization feature; it does not prove that every deleted or corrupt local revision can be recovered from Cloud.
Before a risky recovery, preserve local copies with the Steam client and game closed. If Cloud presents a conflict dialog, compare timestamps and sizes carefully rather than automatically choosing the newest entry.
Manual copies remain valuable before large builds, experimental custom slides, multiplayer sessions on an existing park, mod changes, or opening a migrated Demo save.
Keep Demo migration separate
The Waterpark Simulator Demo is AppID 3730180. Its official store notice says the Demo was updated July 31, 2026 and that old Demo saves are incompatible with the new Demo.
New Demo saves can be opened in the full version, but after the full version opens them they cannot be reopened in the Demo. Copy the Demo save before crossing that one-way boundary.
Do not promise that renaming a backup will convert an incompatible old Demo save. The official Demo notice explicitly limits compatibility.
Escalate with useful evidence
If none of the backups works, return the untouched original folder to a safe state and contact CayPlay at support@cayplay.com or through the official Discord route referenced by the developer.
Explain the public game version, Windows version, park filename, what appeared in the slots folder, which copied backup you tested, and the result. Send files privately only when requested.
Avoid posting a whole user folder in a public Steam thread. It may contain filenames or diagnostic material that is unnecessary for other players.
Save recovery answers
What is the exact save path?
%userprofile%\AppData\LocalLow\CayPlay\WaterparkSimulator\slots
What are .bac files?
CayPlay identifies them as save backups and says up to ten can exist. Test copied candidates one at a time.
What should the recovered filename look like?
The official example changes park.es3.bac1 to park.es3. Do not leave spaces in the filename.
Should I say yes to the Windows extension warning?
Yes for this developer-described rename, after you have made a separate copy.
What if recovery still fails?
Stop modifying the originals and contact CayPlay support with the park and backup details.
Source checked 2026-08-02: CayPlay’s pinned “Need help? Read this first” support post and official Demo notice.