Understanding a grapevine’s water status, which indicates plant water stress, is an integral part of managing a successful vineyard. Unlike other crops, Vitis vinifera, grown for wine production must undergo a balance between cycles of sufficient water inputs and periods of water stress to achieve top quality. Growers may choose to assess water stress using a variety of methods, however, the variability in grapevine type, block size, and subcanopy architecture that can exist within a single vineyard presents challenges to growers aiming to optimize their crop. Monitoring evapotranspiration (ET) in vineyards can be used as a tool to determine water deficits and stress, and to calculate water-use-efficiency, furthering the vineyard managers understanding of crop water status. A multi-scale approach was employed to assess ET at the vineyard, grapevine and grape leaf scale, across two vineyards in the Niagara growing region. Vineyard and grapevine ET/transpiration (T) was captured continuously using eddy covariance and sap flow techniques, respectively, while grape leaf T was assessed instantaneously using a portable photosynthesis system. Vineyard scale monitoring revealed low levels of crop water stress throughout much of the growing season. However, sap flow transpiration methods uncovered variation between red and white varietal T, and water stress dependant on location within the vineyard. Grape leaf monitoring exposed temporal variation in stomatal conductance, transpiration and water-use-efficiency between grape varietals. ET monitoring is an effective method to understanding vineyard water stress, which when extended to growers, will help in successful vine management.