‘Sayama-ike’ is the oldest reservoir in Japan which has been providing an irrigation network to the Osaka plain from the early 7th century. This reservoir greeted the 1400th anniversary in 2016. Up to the present, this reservoir’s dike has been reinforced and heightened repeatedly to increase the reservoir capacity as the irrigation area has expanded. There are many small reservoirs at downstream area where the irrigation network is well developed. The Sayama-ike plays an important role of storing and suppling water to those reservoirs. This network has a unique distribution system with the Sayama-ike as the first-stage reservoir supplying water to the second and then the third ones in cascade, which is known to have been already formed in the late 12th century. In the course of the 16th to the 17th century, the irrigation area of the Sayama-ike became largest, which amounted approximately to 4000 ha. Although the total number of reservoirs at the downstream area is not clear, the main reservoirs counted more than 130 in the early 20th century even though the total irrigation area was decreased. In recent years, the Sayama-ike has been largely upgraded to a multi-purpose one by adding a flood control function, and its name was changed to ‘‘the Sayama-ike Dam’’ after the completion of the upgrading work in 2002. This paper briefly shows its history and current challenges for sustainable management of the irrigation system.

“ Sayama-ike”是日本最古老的水库，自7世纪初以来一直为大阪平原提供灌溉网络。该水库在2016年迎来了1400周年纪念。到目前为止，随着灌溉面积的扩大，该水库的堤坝已经反复加固和加高，以增加水库的容量。下游地区有许多小型水库，灌溉网络发达。yama山池在为这些水库储水和补水方面发挥着重要作用。该网络具有独特的配水系统，其中yama山池作为第一级水库，向第二级，第三级依次供水，已知该水库已在12世纪后期形成。在16至17世纪，Sa山池的灌溉面积最大，约4000公顷。尽管下游地区的水库总数尚不清楚，但尽管总灌溉面积减少了，但在20世纪初，主要的水库仍超过130个。近年来，通过增加防洪功能将Sa山池大体上升级为多用途池，在2002年完成升级工作后，其名称更名为``the山池水坝''。本文简要介绍了灌溉系统可持续管理的历史和当前面临的挑战。尽管总灌溉面积减少了，但在20世纪初，主要水库的数量仍超过130个。近年来，通过增加防洪功能将Sa山池大体上升级为多用途池，在2002年完成升级工作后，其名称更名为``the山池水坝''。本文简要介绍了灌溉系统可持续管理的历史和当前面临的挑战。尽管总灌溉面积减少，但在20世纪初，主要水库的数量仍超过130个。近年来，通过增加防洪功能将Sa山池大体上升级为多用途池，在2002年完成升级工作后，其名称更名为``the山池水坝''。本文简要介绍了灌溉系统可持续发展管理的历史和当前面临的挑战。