The tap is designed to provide water at a good pressure consistently and on demand. There are taps that can undoubtedly operate better than others, with a greater flow of pressure, but in general we know what they can do. So, when you have a with a tap that has a poor water flow rate you can definitely assume that something is wrong. Like all things we would probably condemn the whole system of pipework, but wait as it could be the tap itself that is at fault. The first thing to do in this situation is to look for the source of the water that is being blocked. Bethnal Green Plumbers know what to look for. If the problem occurs suddenly, and is affecting the cold water mains supply to the kitchen sink tap, possibly with the flow stopping completely, it may be worth phoning your water supply company as they are may have turned off the water for some reason like maintenance. Clearly if several taps are affected there is a problem in the pipeline and this will generally be one of the following:1). Affected pipework or mains supply problem.2). Debris in the storage tank causing a blockage3). A plug of ice in a pipe.4). Long time build up of corrosion or limescale.For your low pressure pipework, such as that serving the hot and cold taps to the bathroom, check whether the storage tank in the loft is full of water. Is the lid in place, ensuring vermin have not got into the vessel, drowned and sunk to the bottom, blocking the outlet pipe. The weather will be a sound indicator of whether a blockage is due to ice. A Bethnal Green Plumber can fix water taps.