The online information about this reservoir is sparse, but the top five articles on a google search all claim that it was built during the Japanese colonial period without specifying exactly when. The small size of the reservoir and the relative simplicity of the dam and irrigation outlets are consistent with other small Japanese reservoirs built in Taiwan such as Neipuzih reservoir in Chiayi county and Xishi reservoir in Keelung. Moreover, there is a small shrine located on the eastern shoulder of the reservoir to commemorate the site of a battlefield between the Japanese police and a local "anti-Japanese army" in August 1915. So if the battlefield encompassed part or all of what is now Manzihmanpei (approximately thirteen hectares), then construction of the dam and reservoir must have taken place some time afterwards - so that's anytime between the winter of 1915 and the early 1940s before Japan's surrender in 1945. The question of when exactly Manzihmanpei was built is of interest to me in establishing an historical timeline for the construction of Taiwan's reservoirs.
As the reservoir is very small (about half a million cubic meters in capacity, which is about half the size of nearby Jingmian reservoir [鏡面水庫]), it is not surprising to find that this is a rain-filled reservoir with no feeder stream at the back.
|A view northwestward toward the upstream face of the dam from a small hill to the east.|
|Another view toward the upstream face of the earth dam, with typical Yujing hills in the background.|
|A 300mm shot of the pier below which is a water gate (below the waterline) to allow water out into irrigation canals.|
|A small hut on the western shoreline.|
|A view of the martyr's shrine from the south.|
|Another view toward the shrine from the hills on the western side of the lake.|
|A 300mm shot of the shrine from the west with the Juniper tree just behind it and a number of graves partially visible on either side.|
|Looking northeastward over the lake from the western hills.|
|There are only five herons (?) in this image, but there actually a few more out of shot to either side of the lens. They were, I suspect, sleeping.|
|Looking southeastwards over the fruit farm (these are mostly mango trees, unsurprisingly).|
|A lone eagle, presumably looking for lizards, snakes and fish.|
|Another view southeastwards. The floating object is a bit of hollow pipe, possibly used to hang fishing nets from.|
|A broader view from the west taken with the 10mm lens. The mountains of Nanhua district are in the background and there are electrical cables crossing over the lake.|
|The two pylons standing astride on the hilltops on either side of Manzihmanpei.|