Business development director Tim Briercliffe said: "We want restrictions imposed in a way that has minimal impact on the garden industry."
He said water companies, which had previously resisted any such moves, were "more open and constructive" in this latest get-together.
Colour-coding systems for water shortages would replace hosepipe bans and other restrictions, under the HTA's plans. "Phasing could be based on numbers or colours such as amber and red with restrictions increasing depending on the colour.
"When there was a need for more care with water, retailers would promote the message to their customers. This would rule out the need for draconian bans."
Sustainable Water Industry Group chair Neal Landsberg said: "A phased ban would be good for keeping the issue in the public awareness because now as soon as it rains people think the shortage is over.
"But we must combine this with sustainable policy and education on rainwater harvesting. We should combine the carrot of water and money savings with the stick of some form of restriction."