Kushiro River Meander Restoration — Kushiro Wetland, Japan

Kushiro Shitsugen, Japan's largest wetland and one of its first Ramsar sites (listed 1980), has shrunk from an estimated historical extent near 70,000 hectares to under 30,000 hectares of active wetland today, mostly due to postwar agricultural drainage and channel-straightening of the Kushiro River. Since 2003, the Kushiro Wetland Nature Restoration Council -- government ministries, Hokkaido Prefecture, local governments, NGOs and citizens, formed under Japan's Nature Restoration Promotion Law -- has coordinated restoration across the catchment.

Reverse a mid-20th-century river-straightening project to restore natural meander hydrology and peat-forming conditions in the Kushiro River floodplain.

Completed in 2011, the project reconnected an original cutoff channel and backfilled a 1.6km straightened reach, restoring approximately 2.4km of meandering river channel.

A peer-reviewed decade-later assessment (Sustainability, 2025) found the hydrological restoration clearly succeeded -- flood frequency and groundwater levels rose within a year -- but peat and vegetation recovery lagged well behind: organic matter content in the restored section measured 13.1% (±3.8%), against 24.1% (±11.1%) in a reference well-developed peatland section, and water-holding capacity in the restored area (106% ±32.1%) remained roughly half that of the reference site (229.5% ±148.5%). The same study documents that alder forest continued expanding at the expense of open sedge/grassland peatland vegetation through the following decade.

This is a valuable, honestly-evaluated case of a hydrologically successful but ecologically incomplete peatland restoration: restoring water flow alone was insufficient, since peat soil itself takes far longer to redevelop and continues to shape which plant communities establish.