# Terms of Use

Last updated: 2026-09-26.

By using this site or its API you accept these terms.

1. **Scope** — Dam Data Japan aggregates Japanese reservoir data from
   public sources (国土数値情報 W01/W05/W07, 一般財団法人日本ダム協会 ダム便覧,
   国土地理院 地理院タイル/標高, ja.wikipedia 写真フォールバック) and
   republishes it via this website and the JSON API. Realtime observation
   values are not republished.
2. **Nature of data** — Values are derived from upstream sources via
   normalization, name-matching, and unit conversion. Latency, accuracy,
   and completeness are not guaranteed. **Do not use for decisive
   safety / disaster / legal determinations** — always consult primary
   sources.
3. **Non-commercial use only** — Free of charge for non-commercial
   purposes. Dam attributes, locations, watershed classes and boundaries
   are derived from 国土数値情報 W01/W05/W07 (国土交通省), licensed under
   the 非商用 terms of the 旧国土情報利用約款, so they may not be used
   commercially. Credit the source and the processor, e.g. "出典: 国土数値情報
   (国土交通省)、加工: Dam Data Japan".
4. **API keys** — Issued via Google sign-in at /account/keys. Keys are
   personal. Do not share, transfer, or publish a key. Default rate
   limits are 600 req/min and 100,000 req/day; abuse may result in key
   revocation without notice.
5. **Prohibited** — Disrupting service, sustained load testing without
   coordination, reselling the API verbatim, infringing third-party
   rights, redistributing source data outside the upstream license terms.
6. **No warranty** — Provided "as is". To the extent permitted by law,
   the operator is not liable for any direct or indirect damages.
7. **Governing law** — Japanese law. Tokyo District Court has exclusive
   jurisdiction in the first instance.
8. **Contact** — https://discord.gg/UbWqspWbAk (Discord). No direct email.

Full terms (HTML): https://dam.teraren.com/legal/terms