Lake Buhi lies in the crook of two volcanoes in the Bicol Peninsula -
Mount Iriga (also called Mount Asog) to the west and Mount Malinao
to the east - its surface resting at roughly 120 m above the sea. It spreads across
some 1,707 hectares (about 18 km²) but is remarkably shallow, averaging only
8 m deep and reaching about 12 m at most.
The lake is young, and violent in origin. In 1641 (some accounts say 1628) a strong
earthquake sheared away the south-eastern flank of Mount Asog, leaving the horseshoe
caldera - a 2-by-3.5 km amphitheatre - that scars its summit today. The debris avalanche
swept more than 10 km down toward the plain, burying villages and damming the local rivers. The
ponded water became Lake Buhi. You can read the whole story in this scene: the breached cone of
Iriga on the west, its open gash aimed straight at the water it created.
Lake Buhi is famous for one very small thing. It is one of the only homes of the
sinarapan (Mistichthys luzonensis), a translucent goby barely a centimetre
long - the world's smallest commercially harvested fish. Fisherfolk once scooped it by
the basketful in fine sarap nets; over-fishing nearly wiped it out, and it is now the
subject of a long conservation fight. The town of Buhi sits on the southern shore, and
Itbog Falls tumbles into the lake on its south-eastern side.
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, so the water sits flush with the modeled highland surface rather than a
sea-level guess (radar reads the surface a little below the published 120 m); the underwater
relief is modeled from distance-to-shore scaled to the published 12 m maximum depth.