Water is becoming a scare resource in the state of New Mexico. To ensure that water in eastern New Mexico can be sustained for a longer period of time, existing dairy farms will need to regulate how much water is offered to their cattle and prevent excessive utilization. By using current models to estimate water intake based on environmental temperature, electrical circuits and temperature sensors can be used at cattle water stations to regulate how much water is offered each day to dairy cows. For every 2 oF above the ideal temperature, daily water requirement for each cow increases by 0.5%. By connecting outside temperature sensors to the filling of water bunks, the amount of water available to cows will match the additional requirement for heat stress and prevent excessive consumption. The objective of this experiment is to determine if there is any significant difference in lactation performance between water-restricted cows and unrestricted cows. Ten Holstein cows of similar body weight and milk yield potential will be randomly assigned to 1 of 2 treatment groups. The control group will be offered unlimited amounts of water while the experimental group will be offered their estimated water requirement based on lactation needs and environmental temperature during summer. Milk yield data will be collected for 1 month and data will be analyzed using ANOVA. The hypothesis is that total milk yield will not significantly differ between water treatment groups.