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In order to effectively manage the groundwater, this paper provided a method of choosing the monitoring wells and determining controlled and assessed water level in over-exploitation areas from the perspective of regional and depression cone areas control. For the whole over-exploitation areas, Thiessen polygon method was used to assign control areas to each observation well, and the ratio of the control area of each well to the total area of the region was used as a weight to calculate the weighted average water level of the areas. Then, according to the proximity to the average water level, one regional water level of the controlled well was selected, regarding the water level of the controlled well at the end of the most recent normal year as the controlled and assessed water level. However, if the assessed year was a dry year, assessed water level should set slackness. For groundwater depression cone areas, it used the water level contour map to judge the distribution of the depression cone, and then chose a controlled well which was located near the center of the cone. Then, it similarly regarded the water level of the controlled well at the end of the most recent normal year as controlled and assessed water level. Applying this method to Guantao County, Hebei Province, the monitoring wells of W16 and W17 were selected as regional and depression cone areas of the controlled wells respectively. When the government had not formulated a plan for the water level recovery, the regional controlled water level was determined as 17.13 m. When the government had formulated a plan for the water level recovery (for example, the water level was recovered by 0.5 m within 5 years), the regional controlled water level was needed to increase by 0.1 m every year on the basis of 17.13 m. The assessed water level was equal to the controlled water level in wet and normal years, but the assessed water level in dry years was equal to the controlled water level minus 0.93 m (slackness). The controlled and assessed water levels in the depression cone areas were all determined to be 12.19 m. [ABSTRACT FROM AUTHOR]