Bidar Karez: Upar Dhalan, Neeche Ulta Bahav!

Bidar's Naubad Karez in Karnataka is a 15th-century Bahmani-era underground aqueduct that adapted Persian qanat technology to the Deccan's laterite plateau. Built along a geological fault line, this infiltration-type karez collects rain that soaks into porous laterite and is held up by impermeable Deccan basalt. Reported at roughly 2.6–3.1 km, the tunnel is accessed by dozens of square vertical vents that also work as wells, and floor depressions between vents store water and limit erosion. Its gradient does not follow the surface slope, so gravity moves the water with no pump and very little evaporation. After desilting, heavy rain in September 2015 revived a flow of about 120 litres per minute at the mouth. Falling water tables from borewells remain a threat to this gradient-dependent system. Sources: Archaeological Survey of India (Hydro Nepal journal), Deccan Heritage Foundation, The Hindu, The News Minute. Empirical References: Raghubans K. (ASI), "Qanat System at Bidar District", Hydro Nepal 17 (2015); Bessette & Niblock, Consilience, Columbia University; Deccan Heritage Foundation, Bidar Qanat/Karez project; The Hindu (2017, L. Sridhar) and The News Minute (2018), both featuring V. Govindankutty; Ishraq (Univ. of Nizwa), "The Falaj System in India". Fact-check note: sources report tunnel length as 2.58–3.1 km and mapped vents as 17–28 (about 57 estimated), so the video uses the conservative "2.5+ km" and "28 mapped". Bidar Karez, Naubad Karez, Bidar ka karez, Karez system Karnataka, qanat in India, Persian qanat technology, Bahmani Sultanate engineering, laterite aquifer, ancient Indian water engineering, underground aqueduct India, Surang Bhavi Bidar, Deccan plateau hydrology, gravity flow tunnel, medieval Indian engineering, UPSC history water systems #BidarKarez #Qanat #AncientIndianEngineering #BahmaniSultanate #AspirantsHub3D Technical Disclaimer: Educational AI-assisted 3D reconstruction based on published archaeological and hydrological studies. Geometry, vent count, gradients and flow are simplified and vary by source, the terrain is stylised in white for clarity, and the visuals are not a survey drawing. Set YouTube's altered/synthetic-content disclosure to Yes.