Wherever rice is grown, a reliable water supply is vital. Over centuries, rivulets were channelled from hillside streams to irrigate entire agricultural valleys. Rice will not grow in stagnant water, so constant flow was essential. Any water diversion could have catastrophic consequences further downstream. Period memoirs by district officials, right across Asia, invariably mention water rights issues. When violent inter-village disputes erupted – and New Territories history is littered with these conflicts – water was the usual flashpoint. Water diversion for reservoir construction in the New Territories was the principal underlying cause of rice cultivation disappearing from Hong Kong, beginning with the Shing Mun Reservoir in the late 1930s. Accelerating the process were the post-war Tai Lam Chung and Shek Pik reservoirs, completed in the 50s and 60s, respectively. Plover Cove Reservoir eliminated rice as a going concern around Sha Tin in the 60s when the main streams were diverted to the new reservoir. High Island Reservoir completed the process and, by the end of the 70s, rice cultivation had almost entirely ceasedin the New Territories. Cheap imports hastened the decline of local cultivation. By the mid-60s, processed rice from Southeast Asia – mainly Thailand – sold for less than the local production cost. Chinese rice was also sent to Hong Kong at low cost, further reducing local agricultural viability. Owners of now useless rice fields rented their land to vegetable farmers, who could cultivate crops with less water. Smaller service reservoirs such as Hok Tau, on the Fanling side of Pat Sin Leng, and Ho Pui, above Kam Tin, provided water for other agricultural purposes, including new pig and chicken farms. Easy vehicular access was essential for vegetable farms because growing perishable leafy greens was uneconomic without fast, ready access to markets. Large-scale vegetable farming gradually declined owing to steadily rising labour costs in Hong Kong as well as the migration of younger villagers to Britain and The Netherlands in the 50s and 60s to open Chinese restaurants. Like rice before it, New Territories’ produce could not compete on price with that grown just across the border, and by the late 80s, local vegetable production had drastically declined. By the early 90s, open storage for shipping containers, wrecked cars and construction equipment generated income from the same fields that had previously grown rice and vegetables. Inexorably, any accessible field was paved over and, with no soakage possible, seasonal flooding increased. Blighted former agricultural land became commonplace across the New Territories, enabled by localised corruption, and virtually no government enforcement of environmental protection mechanisms. In remote areas with no road access, sub-economic rice fields never transitioned to vegetables; instead, they reverted to reeds and other plant life that prefers a damp environment. Over the next half century, these abandoned areas – such as Sha Lo Tung – became valuable habitats for a wide variety of bird and insect species. Isolated rice fields have been recultivated in various parts of the New Territories, destroying their ecological value; then when their rice-farming experiment inevitably fails, owners apply for road access and planning permission.