The lake was created in 1900 by the construction of a dam to supply drinking water to the port city of Valparaíso.
It is part of the La Campana-Peñuelas Biosphere Reserve, recognized internationally for its ecological significance.
The reservoir area is a vital stopover for migratory birds traversing the southern hemisphere.
Its ecosystem acts as a natural carbon sink and a regulator for the microclimate of the surrounding hills.
The reserve protects the Chilean matorral, a rare ecoregion found only in central Chile and similar Mediterranean climates globally.
Reserva Nacional Lago Peñuelas is a protected wilderness area centered around a man-made reservoir that serves as a primary water source for the Valparaíso region. The landscape consists of a transitional ecosystem blending sclerophyllous forests with scrubland characteristic of Central Chile. It is designated as a Biosphere Reserve by UNESCO, reflecting its importance for biodiversity and environmental study. The site features significant populations of aquatic birds, including black-necked swans and cormorants, which inhabit the reservoir's fringes. Vegetation primarily includes native species such as peumo, quillay, and boldo trees. The reserve encompasses over 9,000 hectares of diverse terrain, facilitating habitat connectivity between the coast and the inland mountains. Visitors primarily access the area for birdwatching, hiking, and picnicking in designated zones. Due to regional drought cycles in recent years, the water levels in the reservoir have fluctuated significantly, impacting local aquatic habitats. The reserve acts as a critical buffer zone against urban expansion in the Valparaíso province.
The shoreline overlooks near the dam structure, providing wide-angle perspectives of the water and the surrounding forested hills.
Bring high-powered binoculars, as the best birdwatching spots are often far from the main paths.
Carry sufficient water as the site is prone to dry, warm conditions and limited hydration stations are available.
Apply sun protection consistently, as the scrubland offers limited natural shade in many exposed areas.
Do not attempt to swim in the reservoir, as it is a protected water source and strictly prohibited.
Closed on Mondays; hours may be restricted during periods of high fire danger.
Carry out all trash, avoid feeding wildlife, and remain strictly on marked trails to protect the fragile scrub vegetation.
