Turning on the tap to only receive a trickle of water is an alarming issue. There are several reasons why the flow of water can drop from your household taps.

1. Hard Water

Hard water leaves behind mineral deposits, which can crust onto the interior of your water supply lines and constrict the flow. As the issue worsens, the water will slow to a trickle. Hot water lines are affected more often than cold water lines, simply because heat causes more minerals to precipitate out of the water. If caught early, the lines can sometimes be cleaned, but severe mineral buildup may require a line replacement. Installing a water softener can prevent the issue from occurring in the future.

2. Narrow Supply Lines

Narrow water supply lines are more likely to become constricted and they may not deliver the amount of water you are used to from a modern tap. Older homes are sometimes equipped with narrow supply lines. If you have this issue, it may be time to update your plumbing lines to more modern widths.

3. Complicated Line Routes

Water lines that twist and turn throughout the house are more likely to get jammed with mineralization in one of the tight turns, which can slow tap flow to a trickle. In homes with flexible tubing for water lines, a kink can form in the line on one of these twists and turns, as well. It's best for supply lines to have as few bends as possible between the tap and the main water line.

4. Broken Pressure Regulators

There are pressure regulators on individual supply lines as well as a main regulator on the water main. If any of these fail, water pressure can drop and taps will flow at a trickle. If only one tap is affected, the culprit is probably an individual line regulator. If all the taps in the house suffer issues, the issue is likely with the main regulator. Replacement of the affected regulator should fix the problem.

5. Leaks in the Line

A rapid drop in flow can also mean that there is a leak in the water supply line. Begin by checking under the sink to see if there are signs of water damage—wet boards, mildew odors, or standing water. If so, cut off the main water supply line until you can get a plumber to your home.

Contact a plumber for plumbing assistance if your taps have slowed to a trickle.