Another Few Stats on Poulaphouca Reservoir Water Levels and Volume

An ash tree growing on a trail beside the Poulaphouca Reservoir. © Eugene Brennan

In the period from 20th to 31st January, the volume of water in the Poulaphouca Reservoir increased by 52 million m³ of water, corresponding to a 2.3 m rise in level. In the same period, discharges from Golden Falls dam totalled 16 million m³. Since the level in the Golden Falls lake didn't change appreciably over those 12 days, and its surface area is much smaller than that of the Poulaphouca lake, the amount of water that flowed into Poulaphouca must have been equal to the increase in volume plus the amount that flowed out — 68 million m³. Over the 12 days, that gives an average inflow rate of 68/12 million or approximately 5.6 million m³/day. That's about 1.6 times the peak daily flow rate through Kilcullen last week. The Poulaphouca lake is fed by two rivers: The River Liffey and Kings River and so that's understandable. Some small streams also add to the water accumulated.
The ash tree above is on a nice section of path along the lake that leads to the car park on the N81, near the turn for Ballymore Eustace .
Stats are available on the ESB hydrometric website here.