Gate result: oltul-in-trepte (14 Nov 2026) — English only

Pre-registered in PREREG-gate.md before any data was compiled (below).

G1 · dams: PARTLY MET

• The count was read from the source, not assumed: A.B.A. Olt's official dam list (PMRI cycle II, Oct 2023, Annex 4a, 41 dams of category A and B in the basin) holds 27 dams on the Olt main stem between Voila and Izbiceni (plus one small dam at Bălan in Harghita, not part of the cascade). The brief's "two dozen" was a guess; the count is 27.
• That list gives dam height and volume, but no year and no head. So one source for both did not exist.
• INHGA's plant tables give year and gross head for 30 rows. 25 of the 27 dams are in it with a year. Racovița (2019) and Robești (2012) are marked "under construction" there; their years are from Hidroelectrica's March 2026 environmental report. Făgăraș, Lotrioara and Câineni were never finished and are not drawn.
• Second source for years (Hidroelectrica reorganisation plan p.23, CJ Olt risk and territorial plans, a local-history study; transcribed by an AI research assistant (Codex); the author did not open the original): agrees within one year for 22 of 27; Călimănești 1979 (INHGA and GDW 1981); last units at Drăgănești 1989, Rusănești 1992, Izbiceni 1998–2000; Gura Lotrului could not be opened.
• Global Dam Watch gives a year for 17 dams (name join; its Călimănești point sits at Râureni): 13 identical, 17 within one year.
• The INHGA table was transcribed by an AI research assistant (Codex) from a Scribd copy; the author did not open the original. Check: the measured step in the Copernicus model against its heads (page "check" section): median difference 1.5 m, 16 of the 26 dams the model can see within 2 m (Racovița, built 2019, is after the 2011–15 model).
• Verdict by the pre-registered rule: PARTIAL (two sources, each number tagged).

G2 · drowned settlements: NOT MET (0 of 5)

• Two Codex searches (local history, press, Austrian third-survey index, Wikipedia, decree searches) and our own read of the ro.wikipedia pages of 30+ riverside communes found no settlement with both required documents.
• Traces that do not qualify: Robești kept in place (Adevărul article); Râul Vadului and Priloagele named in 1978 for relocation under a larger reservoir never built (Flacăra, 29 Jul 1978; Transalutania pp. 52–53); Mândra lost land to water (Arhiva Satului Șona study); Luncani near Brezoi is on the Lotru.
• Arcanum's Austrian third-survey sheets returned HTTP 403 to Codex's fetcher.
• The page therefore names no drowned village. The reader's own result is the nearest lake and its numbers.

Manual sheet (to close G2)

• Arhivele Naționale, Direcția Județeană Vâlcea and Olt: files on "strămutare" / "expropriere" for the 1970s Olt dams (Turnu, Călimănești, Dăești, Râmnicu Vâlcea, Govora, Băbeni, Ionești, Zăvideni, Drăgășani, Strejești, Arcești, Slatina).
• maps.arcanum.com, Third Military Survey 1:25,000 (1869–87): open the sheets over each lake in a normal browser, list settlements and mills inside the lake outline; then confirm each in the commune monograph.
• The 1:25,000 Romanian military sheets (1960s) from the Direcția Topografică Militară, same comparison.
• Commune monographs and the 1966 census locality lists against SIRUTA 2026.

Live water level

No open feed found; not shown.

Landsat check

Median gap between Landsat's fill year and the documented year over the 19 lakes whose filling the satellite saw: 1.0 years.

PREREG: Oltul în trepte, gate (written 14 Nov 2026, before any compilation)

Question: can the Olt staircase be told from documented, dated numbers, not guesses?

Gate G1, the dams

• The set of dams is whatever ONE named source lists for the Olt main stem (Hidroelectrica or a published list). The count is read from that source when opened; it is not assumed (the brief's "two dozen" is unchecked).
• PASS: for every dam in that source, a commissioning year AND a head (height of fall, metres) are printed in that same source. A dam missing either is listed as missing on the page.
• PARTIAL: one source gives years, another gives heads. Then each number is labelled with its source and G1 is reported as "two sources", not as passed.
• FAIL: fewer than 80% of listed dams have both numbers in one source. Page then says so and shows only what is documented.

Gate G2, drowned settlements

• PASS: at least 5 settlements (or hamlets / named parts of settlements) that stood where an Olt reservoir now is, each with (a) a document naming it before flooding (old topographic sheet, Austrian third survey 1869-87, census, published local history) and (b) a document that links it to the reservoir.
• A settlement counts only with both documents opened and the reference written down. "Said to be under the lake" without a document does not count.
• FAIL: fewer than 5. Page then says how many were found and what was tried.

Other rules

• Lake-filling imagery: Landsat (1984 onward) lake-area series per reservoir; earlier dams are shown as "filled before the satellite record". No lake extent is drawn by hand.
• Live water level: only with a real open feed found; otherwise not mentioned on the page.
• Failed or partial gate results are shown on the page.
• If a target is missed, Codex is asked for more sources before settling.

Back