Lake Buluan spreads across roughly 61 km² of the Mindanao lowlands,
sandwiched between Maguindanao del Sur and Sultan Kudarat - the third-largest
lake on the island after Lake Lanao and Lake Mainit. It is also one of the
shallowest: averaging only about 4.5 m deep and reaching some 6 m at most, it
is really a broad pooling of the adjoining marshy basins of the Pulangi, Maanoy,
Buluan and Alah rivers, all tributaries of the Rio Grande de Mindanao.
Its own outlet, the Buluan River, runs 109 km north to Liguasan Marsh before
joining that great river system.
The lakeshore is shared by four towns - Buluan and Mangudadatu in
Maguindanao del Sur, President Quirino and Lutayan in Sultan Kudarat - and
before the American era the whole basin lay within the Sultanate of Buayan. Maguindanao
Moro communities have fished and traveled this waterway network since at least the 14th century,
and the lake remains the lifeblood of the towns around it.
Since 1929 the lake has been a national Game Refuge and Bird Sanctuary,
covering some 84 km² of open water and marsh that draws migratory waterbirds. It is
also one of the country's most productive fisheries: its shallow, sun-warmed water once yielded
close to 10,000 metric tons of fish a year, and today bamboo tilapia cages
quilt its surface as government programs help lakeshore families expand aquaculture.
Built live in your browser from real data: NASA SRTM elevation (Mapzen terrarium tiles from
AWS) decoded pixel-by-pixel and displaced at true horizontal scale, draped with Esri World
Imagery, plus a finer imagery inset over the lake. The lake datum is sampled straight from the
elevation grid (radar is noisy over open water, and this shallow basin sits barely above the
surrounding floodplain), and the underwater relief is modeled from distance-to-shore scaled to
the published 6 m maximum depth.