so was larraos. only ruins are left.ther villages are less public about what's happening, because their situation is precarious. >> robejildo taipes is unwilling to leave his village to its fate. he helped build this fence to create a water protection area. the barbed wire is designed to keep animals away from the yanacuncha glacial lake -- a lifeline for miraflores. reed beds are being planted and water tanks built to prevent the water from evaporating or draining away. >> this pipe system is intended to provide the valley with water. it should be easy to manage. it will irrigate the pastures and ensure the animals' troughs are full. >> it's the same system used by their ancestors, say robejildo taipes and plinio reyes. >> we have a precise rotor for irrigating the fields. tomorrow it is dennis' turn. but today, senora linda's fields are being watered. we can even determine how much water the fields get, and when. >> making the most of resources is a skill locals here have mastered for centuries. it is just a question o