A temporary discount combined with a limited-time rebate is helping San Diegans save 90 percent on 50 gallon rain barrels through the end of the year. After the SoCalWaterSmart Program increased its rain barrel rebate from $35 to $75, the San Diego County Water Authority announced that it will sell 50 gallon rain barrels through the Solana Center for $90, down from its normal $149 tag. So, from now until the end of the year, water-conscious locals can take home rain barrels for just $15.