Definition - What does Water Sprout mean?
A water sprout is a small shoot that emerges from a latent bud in a grapevine. Water sprout growth can result from stress and damage, or in response to pruning. Shoots that grow from water sprouts can be highly susceptible to diseases and pests, as well as producing little fruit. They are generally pruned away to promote vine health and ensure a good yield of grapes.
WineFrog explains Water Sprout
Water sprouts in grape vines are one of the plant's natural responses to damage, such as weather damage. It can also occur due to over-pruning, so it's important to prune the vines carefully. These vigorous, fast-growing shoots tend to grow somewhat vertically and tend to be weaker and less robust than normal shoots. Their vertical growth habits can block light and divert nutrients away from healthier parts of the vine, and water spouts are also prime locations for diseases and insect pests to attack the plant. Because of this, water sprouts are generally removed close to the vine to discourage their regrowth.