Over the past year, San Diego’s water department refunded over $650,000 to hundreds of customers who received unjustifiably high water bills. The payouts are another sign of how water customers were affected by bad bills from the city. Over 1,100 customers received refunds this year, meaning the city overcharged the average customer by more than $500. The number and cost of refunds has dramatically risen in recent years, according to department records analyzed by Voice of San Diego and NBC 7 Responds as part of an ongoing investigation into the water department’s billing practices.