Other shops reported selling out, with the Taradale Four Square expecting a big delivery today to replenish its sold-out stocks.
Foodstuffs Ltd, spokeswoman Antoinette Laird said more supplies had already been brought into the city.
"Sales of bottled water in PAK'nSAVE supermarkets in the Napier area were pretty brisk yesterday in response to the water reservoir issue.
"More supplies were delivered overnight and yet more bottles are on their way. There's no need to panic buy. We'd like to remind people to recycle responsibly."
She added there was no truth to social media posts suggesting supermarkets had raised prices.
"PAK'nSAVE and New World would like to reassure customers that bottled water prices are normal. Contrary to rumours circulating on Facebook there have been no increases.
"There is plenty of bottled water to go around thanks to a shipment overnight, and there are more supplies on their way."
Following Mayor Bill Dalton's suggestions yesterday that residents excessive sprinkler use were to blame for the water shortage, social media was alive with suggestions there could be other reasons to blame.
A spokeswoman for the regional council also pointed out that the One pure water bottling plant in Napier would not have had an impact on water levels.
"One Pure takes water from a separate point which is a private bore.
"HBRC understands the issue for Napier City is the ability to refill the reservoir as opposed to the aquifer's capacity."
One Pure was granted resource consent in December 2014 by the Napier City Council to operate a water-bottling plant at the site, and a water-take consent by the Hawke's Bay Regional Council.