Located in the semi-arid Rayalaseema region, which receives erratic rainfall (~550–600 mm annually), the fort could not rely on perennially flowing rivers or deep groundwater tables due to its elevated granite topography. Instead, ancient military engineers designed a decentralized, gravity-fed, multi-tiered rainwater harvesting network.
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| Ruined Gooty Fort, Andhra and water pond |
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| water harvesting in ancient India myindiamyglory.com |
1. Geology & Topographical Strategy
Geologicall speaking the fort is situated on an imperial batholith composed of massive, impermeable crystalline granite. Rather than fighting this hard rock, engineers leveraged its impermeable surface as a giant catchment apron.
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| Step well (Baoli) ancient management system India indulgexpress.com |
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| Ancient India and water management system Stepwell deccan-heritage-foundation.org |
Above image: Roughly 3500 years ago, the earliest ancient Indian communities in the semi arid areas were dependent on the Monsoon rainfalls.They carefully planned large scale water management by constructing reservoirs using rubble and mud mortar to capture monsoon runoff.................
Catchment Efficiency: Rain falling across the 680-meter-high hill slopes was directed down natural rock gullies and fissures (clefts) rather than being allowed to run off into the valleys below.
Structural Integration: By cutting reservoirs directly into natural fault lines and depressions, engineers minimized the need for structural retaining walls, eliminating major leakage points under high hydrostatic pressure.
2. The Network of 108 Wells and Cisterns
The fort features 108 documented water bodies categorized into three distinct functional types:
a. Hydraulic Structure :Rock-Cut Cisterns (Konerus):
primary function: Primary runoff capture
Engineering Characteristics: Deep rectangular tanks carved directly into granite; lined with lime-surkhi plaster to prevent seepage through micro-fractures.Stepwells (Bawlis)
b. Hydraulic Structure: Stepwells (Bawlis)
primary function: Domestic supply & troop access
Engineering Characteristics: Tiered access staircases extending down to lower water levels, reducing evaporative surface area while keeping water cooler
c. Hydraulic Structure: Citadel Ponds (Siri Koneru)
primary function: High-security reserve
Engineering Characteristics: Perched at the highest elevation near the granaries to supply the garrison during prolonged sieges.
3. Filtration and Quality Control
Raw surface runoff from rock faces carried silt, debris, and organic matter. To ensure water was safe for long-term storage and consumption, the system integrated natural treatment mechanisms:
Siltation Basins: Inflow channels passed through preliminary settling basins before reaching main storage wells, allowing suspended solids to settle.
Lime Plastering (Surkhi):
Reservoirs were lined with a mixture of hydraulic lime, burnt brick dust (surkhi), and botanical additives. The lime provided waterproofing and raised pH slightly, preventing algal blooms and bacterial growth during hot months.
Shaded Storage: Deep, narrow rock-cut trenches minimized direct sunlight exposure, significantly slowing evaporation rates during peak summer months.
4. Vulnerabilities and Historical Impact
Despite its sophisticated design, the system had a singular point of failure: dependence on seasonal monsoon replenishment.Because the fort relied entirely on collected surface water rather than deep artesian aquifers, prolonged droughts or multi-month sieges without rainfall could deplete reserves. This precise vulnerability led to the downfall of Maratha general Murari Rao Ghorpade in 1775 CE: Hyder Ali’s forces encircled the fort and held their positions until internal water supplies dried up, forcing Murarirao to surrender after two months without a single breach of the physical walls.
https://www.indulgexpress.com/life-style/travel/2026/May/03/a
https://www.youtube.com/watch?v=SQR1DdXX7jc
https://www.deccan-heritage-foundation.org/ancient-water-systems-across-the-deccan
K. N. Jayaraman Ph. D (1977) Univ. of Washington, Seattle.
Retd. Earth Scientist. Vocational Interest: Indian Colonial history, architecture of heritage structures,colonial buildings, temples,etc.
(Author: navrangindia.blogspot.com)
