This dataset is one of many developed in support of The High Plains Groundwater Availability Project and the U.S. Geological Survey Data Series Report: Geodatabase Compilation of Hydrogeologic, Remote Sensing, and Water-Budget-Component data for the High Plains aquifer, 2011 (DS777). This dataset represents a thickness-weighted average of hydraulic conductivity (K) and specific yield (Sy) for 4,309 well points in the northern High Plains aquifer. Hydraulic conductivity is a measure of how much water flows through a unit section of an aquifer, under a unit gradient in a specified amount of time. Specific yield is a measure of how much water will drain from the aquifer by gravity. Both of these properties are important to develop a hydrogeologic framework for an aquifer and to gain an understanding of how water flows through the aquifer. Included in this metadata document are the attribute definitions of all tables related to the feature class pts_K_Sy_TWA, including tbl_K_Sy_RawDataMaster a table of well point lithology records that terminate at the base of the aquifer. This document also includes the attribute definitions of the table of subsurface material, called tbl_Material that contains texture, grain-size, and sorting properties of the aquifer material, and the attribute definitions of the table of multipliers called tbl_Multiplier, which, based on certain subsurface materials, would reduce the computed values of these properties. The two tables, tbl_Material and tbl_Multiplier are used in the Geoparm macro to compute the K and Sy values at the wells in the pts_K_Sy_TWA feature class. Attribute definitions for tbl_K_Sy are also included in this metadata document; tbl_K_Sy is the output table created by the Geoparm macro. The thickness weighted averages of K and Sy are computed by queries in this table after the macro is run. The thickness weighted averages were then transferred to the point feature class. (pts_K_Sy_TWA).