Auckland's water shortage is officially over. Watercare says it has been slowly increasing capacity at its Ardmore plant in the Hunua Ranges, following heavy rain late last month. It is now running at 70 per cent capacity. The council-owned water company is also looking at ways to prevent future shortages. Watercare spokesman Mark Bourne said increasing the capacity of the water has been a careful balancing act. "Since 15 March, we've been slowly increasing the capacity of our Ardmore Treatment Plant to 250 million litres of water per day. "At the same time, we've been adjusting production at our other plants to sustainable levels. "We're working with Auckland Council to identify measures that can be implemented to manage slips in the Hunua Ranges. "We're investigating how we can adapt our Ardmore Water Treatment Plant so that it can treat water with higher levels of silt more easily. Bourne said even the most robust water system would have been affected by last month's historic deluge. But he said the agency plans to spend $1.9 billion over the next ten years to upgrade water infrastructure and make the system more resilient. That will include "securing new water sources, building new water treatment plants, water storage reservoirs and pipelines". Watercare does not plan to change the way it communicates with the public, such as by setting up dedicated Watercare social media accounts. Bourne said the agency communicated through the media, Auckland Council and Auckland Civil Defence, and plans to continue doing so. "I think those channels have worked because we have seen a significant reduction in water consumption." The unprecedented rainfall on March 7-8, dubbed the Tasman Tempest, delivered more rain in a few hours than typically falls in the entire month of March. Landslips and silt washed down from the Hunua Ranges clogged the water filters at the Ardmore plant, which meant it struggled with treatment. Ardmore provides two-thirds of Auckland's water. According to Niwa's High Intensity Rainfall System, the 225mm that fell in 12 hours on March 7 in Upper Hunua exceeded a one-in-100 year event. Auckland, according to readings taken at Mangere, tied its wettest March hour on record with 27.6 mm between 5pm and 6pm on March 10 since hourly records began in 1965.