This reservoir doesn't seem to have a name on the map or on the internet but I just went there to see what it would be like.
There was no name even there! Whether it has a name or not, the place looked great for some birds. The whole area around the reservoir and the reedbeds was fenced so as the wildlife there is not disturbed.
Quite a few Teals (Kogamoコガモ) were in the water and the males were busy calling and dancing around the females.
Wonder if he was successful?
A Buzzard (Nosuriノスリ) was being mobbed by a Thick-billed Crow (Hashibutogarasuハシブトガラス) high in the sky. Eventually the Buzzard swooped down and disappeared in the woods.
An Oriental Turtle Dove (Kijibatoキジバト) and a pair of Oriental Greenfinches (Kawarahiwaカワラヒワ) were foraging near the path.
A gorgeous male Daurian Redstart (Joubitakiジョウビタキ) perched on a low branch for a minute or so and flew into the thicket.
I'd say a scope is essential to see more birds here.