If pressure is a problem, a booster pump may help. If volume is a problem, a larger water line may be in order. A lot of times, especially if you are in an older area, the city water systems are old and riddled with leaks. Since it is difficult and costly to locate and repair them, the city will just figure it in as a cost of doing business and pass the increased costs on to the customers. Pressure on the city administration may be in order. My city recently found a 3 million gallon a day leak that went undetected for a long time. Are there any other businesses close by that would consume lots of water? Maybe when they are, you are losing volume and/or pressure as a result.