What a roof in Bandipur could catch in a typical year, which months would fill a tank, and how many days of household water that is — with how much rain has actually fallen in the last 30 days.
Loading the latest information…
Town Tools builds free, public tools for Bandipur and towns around the world. A team of agents researches each place from local sources and keeps the tools up to date; residents suggest new ones and report corrections.
Bandipur sits on a ridge with no river and no spring at the top. Every litre that reaches the bazaar is pumped or piped up from lower down, which is why the Tin Dhara taps are still in daily use and why the supply thins out in the dry months before the monsoon. Rain is the one water the ridge gets for free — about 1,824 mm of it a year, though two-thirds arrives between June and September.
In a typical year, this roof could catch about
73,000 litres of water
from about 1,824 mm of rain a year
Litres this roof catches each month of a typical year. The rains do the work in a few months — storage carries you through the dry ones.
About 650 mm of rain has fallen in the last 30 days — enough for this roof to have caught roughly 26,000 litres.
These are estimates, not a promise
Live rainfall from Open-Meteo (CC BY 4.0) — a weather-model estimate for the area, not a rain gauge on your street. Updated .
Rain off a roof is not drinking water
Rainfall varies a lot around here
Assumes a hard roof — corrugated iron sheet, tile or concrete — with gutters in reasonable order. About a fifth of the rain that lands is lost to splash, gutter overflow in heavy monsoon downpours, and the first-flush water you throw away. A thatched or badly guttered roof catches considerably less.
Counted at 45 litres per person per day, the basic service level Nepal's rural water-supply guidelines design village systems around (bazaar systems are designed at 60). It covers drinking, cooking, washing and sanitation. Many households on the ridge get by on less, especially in the dry months — so if your own use is lower, the water will stretch further than the figure below.
Roughly two-thirds of Bandipur's rain falls in the four monsoon months. November through March get under 40 mm a month between them, and the pre-monsoon stretch from February to May is when ridge-top supply is thinnest. A tank sized only to catch a good monsoon downpour will overflow in July and stand empty in March. The number that matters is not what falls in the wettest month but how much you can still be holding in the driest.
Bandipur is a saddle on the Mahabharat range at about 1,030 m, with no watercourse at ridge level. Supply has to be lifted from sources below, and the monsoon that brings the rain is the same season that puts landslides through intake pipes and across the Dumre road. Stored rain is one of the few things on the ridge that does not depend on that road staying open.
Fit a simple diverter — a length of downpipe that fills and closes off before the clean water reaches the tank — so the dirtiest water from the start of each storm never gets in. It is the cheapest single thing that improves what comes out of the tap.