Transmission Siting Disclosure Capture: TVA, Oncor/LCRA and Dominion Energy Virginia, August 2026

A point-in-time capture of publicly published transmission line siting geographic data, retrieved 15 August 2026 by anonymous query against public ArcGIS REST endpoints. No authentication, token or credential was used. Why this exists. The Tennessee Valley Authority publishes its transmission siting data as live web services under its sole control, revisable without notice, with no docketed version and no third party holding a copy. Research relying on those services cannot cite a stable record. This deposit fixes the bytes as of the retrieval date so that findings drawn from them remain checkable, and so that any later change to the source is detectable. Contents. Tennessee Valley Authority, TSSProjects_Hosted (organisation w8auYAijfGK1Mydj): route alternatives layer (2,645 records), selected centerline layer (447), right-of-way and substation layers, service definition and full layer metadata. The complete 302-service organisation directory. ArcGIS Online item metadata and web map definitions for eleven items. Lower Colorado River Authority / Oncor, Permian_CCN_External_Open_House: route segment layers, study areas, service definition and layer metadata, captured for comparison. Deliberate omissions. Two categories of record present in the source services were not captured, and their layer metadata is included instead so that their existence is documented without reproducing the data. First, LCRA/Oncor parcel and “Habitable Structures” layers, which map individual homes and named private landowners. Second, the feature records of TVA's GeneSIS_Layers generation-siting service, comprising 151,858 tax parcels carrying landowner names and mailing addresses. Both are anonymously queryable at source; neither is republished here. Integrity. MANIFEST.txt lists every file with byte count, feature count, SHA-256 hash, and the exact source URL and query string. Figures published from this dataset should cite the file and hash rather than the live endpoint. Method note. The route alternatives layer contains substantial duplicate geometry: 2,645 raw records reduce to 1,430 unique segments. Any sum over the raw layer overstates total corridor length by roughly 84 percent. See MANIFEST.txt. Addendum, 18 August 2026. Eighteen Dominion Energy Virginia landowner-facing transmission project pages were added as a control set. Dominion files a full adversary certificate case at the Virginia State Corporation Commission; TVA files no siting case at all. The Dominion set is a purposive sample and not a census, enumerated from dominionenergy.com/sitemap.xml because the project index is client-rendered, and weighted toward data-centre corridors. The two counts of eighteen are not the same kind of number. The Virginia SCC dockets behind fourteen of the pages were not read. MANIFEST.txt states the method and its limits in full.