Anuradhapura Kuttam Pokuna water filtration: desilting chambers and ceramic filter tiles?

The 8th-century Kuttam Pokuna (Twin Ponds) in Anuradhapura incorporated advanced pre-modern water filtration. Water diverted from the Basawakkulama irrigation tank did not flow directly into the bathing pools; instead, it entered an external, enclosed stone settling basin where flow velocity dropped, causing suspended silt and organic detritus to precipitate to the floor. Clarified water then passed through subterranean stone masonry conduits fitted with perforated ceramic filter plates, ensuring pure water emerged through the carved Makara stone spouts into the northern bath.