Iran Reservoir Transparency

Iran's institutional disclosure of reservoir data is materially stronger than press-only leakage, but still falls short of structured public dissemination. The Water Information and Data Office (دفتر اطلاعات و داده های آب کشور) at data.wrm.ir, established in the Iranian year 1400 (2021/22) as part of the Ministry of Energy's restructuring, produces a regular 'Weekly Report on Precipitation and Dam Status' (گزارش هفتگی وضعیت بارش و سدها). The IWRMC publishes aggregate national reservoir storage figures that flow into press citations — 18.77 Bcm (34% of capacity) reported for early February 2026, 17.46 Bcm reported December 2025, 20.47 Bcm (39%) at other points — alongside dam-count statistics (19 dams below 5%; 64% of capacity empty). The dams.wrm.ir portal carries an inventory of Iran's large dams, and the Sediran national water observatory was launched explicitly to consolidate resource and operational data on dams. Eleven Regional Water Authorities (Tehran, Khuzestan, Isfahan, Fars, Khorasan Razavi, South Khorasan, etc.) publish provincial dam totals (e.g., Isfahan reporting Zayandeh Rud at 371 Mm³ / 31% capacity; combined Isfahan provincial total 276 Mm³). However, the data is delivered overwhelmingly through PDF bulletins, HTML pages with embedded numbers, and ministerial press statements rather than per-dam machine-readable feeds. Live, granular fill % time series for individual major reservoirs (Karkheh ~5.9 Bcm, Karun-3 ~2.97 Bcm, Karun-4, Dez ~3.34 Bcm, Latyan, Taleghan, Zayandeh Rud) are not openly browsable as a national dashboard.

No public REST API, no documented machine-readable endpoint, and no OGC service exists for Iranian reservoir storage data. The data.wrm.ir portal distributes weekly precipitation/dam reports as PDFs and HTML pages under /cs/Download paths, organised by file groups but without bulk download manifests, structured CSVs, or programmatic access. The wrs.wrm.ir/amar hydrological statistics portal requires user registration via login.asp; once authenticated, it provides validated river flow and water-quality data, but reservoir storage time series are not the focus and bulk export is not advertised. The stu.wrm.ir archive holds the validated 1964–2020 river chemistry/discharge dataset (5.97 million records from 1,591 stations), but again is not a reservoir storage feed. No SCADA stream, no JSON endpoint, no GeoJSON export, no published technical interface. The Iran Open Data Center (iranopendata.org) maintains scrapers and republishes some IWRMC data via GitHub, but explicitly as an external civic-tech intermediary rather than via any government-supplied API. The 2026 IOD 'AI-powered data hub' announcement underscores how much value-add must be done outside Iran to render the underlying data machine-readable.

Audit revision (2026-05-29): the denominator for RTI coverage is reservoirs with capacity >10 hm³, NOT all dams. Iran's relevant denominator is approximately 150-200 reservoirs >10 hm³ — the 176 large dams identified by IRCOLD that hold ~49.2 Bcm (~95%) of the ~51.7 Bcm total national dam capacity. The often-cited '523 large dams' or '647 dams in operation' figure includes many smaller diversion dams, weirs and irrigation structures well below 10 hm³ and is not the correct denominator. IWRMC's weekly precipitation and dam status bulletin covers approximately 193 monitored reservoirs — effectively the entire >10 hm³ population plus margin — including Karkheh (5,900 Mm³), Karun-3 (2,970 Mm³), Karun-4, Dez (3,340 Mm³), Gotvand, Latyan, Amir Kabir/Karaj, Taleghan, Lar, Mamlou, Zayandeh Rud, Doroodzan, Dosti, Golestan, Sefidrud and the Tehran-feeding five. Eleven Regional Water Authorities (Tehran THRW, Khuzestan KWPA, Isfahan ESRW, Fars FRRW, Khorasan Razavi KHRW, etc.) publish provincial aggregates that — combined — cover essentially every large dam in their jurisdictions. The result is near-complete coverage of the >10 hm³ population at the aggregate level (95-100%); the disclosure quality issue (PDF/HTML/press, not per-dam live time series) is captured in other dimensions (technical_accessibility 18, data_availability 58, update_frequency 55) rather than coverage. The previous 62 score conflated coverage with accessibility.

Long historical records exist within the IWRMC system. The stu.wrm.ir validated archive contains river monitoring data from 1964–2020 (1,591 stations, 5.97 million records, covering surface water flow and water quality). Iran operates 1,730+ active gauging stations distributed across 6 primary and 30 secondary hydrological basins, with data feeding national archives going back decades. The wrs.wrm.ir/amar portal hosts annual flow and precipitation series. Academic papers cite IWRMC-sourced operational time series for Atatürk-comparable infrastructure such as Karaj Dam (2015–2025), Karkheh, Karun, and Dez spanning multiple decades. However, none of these series is currently published as a public, downloadable, queryable reservoir storage time series — researchers obtain them via institutional cooperation or registered access. The Iran Open Data Center's freely accessible dam dataset still covers only a single year (1396 / 2017–18). For the standard public user, historical reservoir storage online is essentially limited to whatever can be reconstructed from press archives plus the 2017–18 IOD snapshot.

Iran's update cadence is stronger than initially apparent. The Water Information and Data Office produces a documented weekly precipitation and dam status bulletin (گزارش هفتگی وضعیت بارش و سدها), and IWRMC issues current-week aggregate numbers that are picked up by IRNA, ILNA, Tehran Times, Iran International, and Iran Focus on a sub-monthly cadence with figures dated to the prior week (e.g., 'by February 1 of the 2026 water year' reported February 6). Regional Water Authorities issue periodic provincial updates. Daily analytical reports on dam reservoir status are reportedly produced internally and circulated through the national government services portal. However, the public-facing delivery is the weekly PDF bulletin plus ministerial statements — not a live daily dashboard like Turkey's DSİ portal or Spain's MITECO SAIH. Mashhad's Dosti Dam falling to 2% capacity was tracked in real time by officials but disclosed through press conferences, not an automatic feed. Effective sub-weekly disclosure exists only for crisis communications.

Iran's measurement and capacity-accounting methodology is not publicly documented to international standards. IRCOLD (Iranian National Committee on Large Dams) publishes a dam inventory and conference proceedings in English with structural specifications, but no national manual explains how daily/weekly fill percentages are derived, how stage-storage curves are updated, how sedimentation adjustments are applied, or how QA/QC is performed. AQUASTAT reports a total dam capacity of 44.4 km³ for Iran (2022, with usable storage distinct from gross capacity), but the underlying Iranian methodological documentation is not online. The 1,730-gauging-station network has operating standards within IWRMC but no public technical manual. Independent analysts and journalists routinely cite IWRMC aggregate figures with no accompanying methodological footnotes. Water data in Iran is treated as quasi-strategic information, and academic literature accessing operational data does so via institutional cooperation rather than public methodology disclosure. The Sediran observatory project hints at a more documented internal process but is not externally documented.

All primary operational portals (data.wrm.ir, dams.wrm.ir, wrs.wrm.ir, news.moe.gov.ir) are predominantly Persian. The main IWRMC website (wrm.ir/?l=EN) and many Regional Water Authority sites (thrw.ir/?l=EN, khrw.ir/?l=EN, skhrw.ir/?l=EN, frrw.ir/?l=EN, esrw.ir/?l=EN) offer English-language landing pages — a modest improvement over the previous evaluation — but the English versions present institutional and organisational content, not operational reservoir storage data. The Ministry of Energy's Paven news portal exposes an /home?lang=en-US English interface with limited current-affairs content. IRCOLD publishes English-language dam inventory data. International English coverage (Tehran Times, Iran International, Al Jazeera, Reuters, Iran Focus) regularly relays IWRMC-sourced aggregate figures, providing reasonable English visibility of national totals via press, even when no direct English data portal exists. The Iran Open Data Center (iranopendata.org) publishes some English-language datasets of dam infrastructure (current detailed inventory dated 2017–18). The net language usability is weak but slightly better than initially scored: an English-speaking researcher can establish basic situational awareness but cannot directly query operational data without translation.