Before Saroma’s two manmade passages to the ocean were constructed, the lake would naturally flood and overflow (aided by some human intervention) each spring, at its eastern end. During this brief period, saltwater would backwash into this shallow, narrow part of the lake, causing it to be more brackish and good for farming saltwater species such as oysters. Near this old outlet, which no longer floods from runoff since it is subject to the natural flow of tides into the lake, I discovered an unmapped road that actually loops back onto the main road behind a sugar beet processing plant, as well as this monument marking the location of Saroma Lake’s erstwhile connection to the ocean. Japanese text and English translation below.
The Former Mouth of Saroma Lake
Originally, the outlet connecting the lake to the ocean was in this vicinity. Every spring people would dig to help reopen the channel. In Showa 4 (1929) a drainage channel was excavated on the Yubetsu end of the lake, causing tides to affect the lake and naturally close this outlet.