Historical clue formulations

• Structure for hydroelectric power — 2026-07-13
• Fish ladder locale — 2026-04-13
• Reservoir producer — 2026-02-18
• Renewable energy structure — 2026-02-15
• Leave it to beaver? — 2025-04-18
• Prevent from running — 2024-12-27
• Block — 2024-08-03
• Reservoir creator — 2024-07-17
• It holds a lot back — 2024-06-05
• Structure that's subject to hydrostatic pressure — 2024-05-29
• Block (up) — 2024-04-21
• Irrigation structure — 2023-12-21
• Bad thing to burst — 2023-11-15
• Reservoir producer — 2023-05-16
• What the fish said when it swam into a concrete wall, per an old joke — 2023-03-20
• Power project — 2023-01-08
• Block — 2022-12-03
• Hoover, for one — 2022-10-30
• The tallest one in the U.S. is California's Oroville — 2022-09-22
• Leave it to beavers — 2022-05-01
• Army Corps of Engineers project — 2021-07-30
• Something to leave to beavers? — 2021-07-11
• Locale for a salmon ladder — 2021-06-17
• Stop up — 2021-06-16
• It holds water — 2021-02-11
• Hoover ___ — 2020-05-25
• Moat feature — 2020-04-04
• Horse's female parent — 2020-02-02
• Beavers' construction — 2019-12-30
• The world's largest one is in Hubei, China — 2019-09-27
• Put a stop to? — 2019-05-31
• Obstacle for a fish — 2019-04-07
• Hydro plant locale — 2019-01-27
• Stop (up) — 2018-12-18
• Beaver's construction — 2018-10-01
• Feature of a moat — 2018-08-04
• Beaver's project — 2018-07-09
• Feature of a millpond — 2018-05-06
• Arizona's Glen Canyon, for one — 2018-04-05
• Stop the flow of — 2018-03-08
• Challenge for salmon — 2017-12-27
• Channel changer? — 2017-12-09
• Flow stopper — 2017-08-24
• Fish ladder site — 2017-07-06
• Hydroelectric project — 2017-05-03
• Fish ladder site — 2017-02-04
• Reservoir creator — 2016-12-12
• Nevada/Arizona's Hoover ___ — 2016-08-29
• Montana's Hungry Horse ___ — 2016-07-14
• China's Three Gorges ___ — 2016-03-17