Here we present the results of stable carbon isotope (δ13C) analysis on charred crop seeds from the Bronze Age site of Kaymakçı in western Anatolia. The δ13C data, in conjunction with some 14C-dated seeds, allows for insights into the water availability for crops and a comparison among taxa, enabling a relatively high-resolution investigation of field agriculture, crop cultivation, and crop and field management around the site. From this data, we discuss agroeconomic structures and local paleoenvironmental and paleoclimatic conditions in the local micro-region, as well as more generally for western Anatolia. A total of 35 single carbonized seeds were analysed, including seeds of wheat, barley, bitter vetch, pulses, and grape. Almost all samples date to the first half of the second millennium bc, based on radiocarbon dating of 24 seeds from the sample assemblage. The δ13C data demonstrates that crops at Kaymakçı were generally moderately to well-watered, and water availability was likely not a limiting factor for growth. This water availability is unlikely to result from artificial and man-made irrigation systems, however, but rather crop-management and field-location choices, taking advantage of the humid conditions along the shores of Lake Marmara and in surrounding wetland environs. A seeming paradox is the ubiquity of risk buffering crops (barley and bitter vetch) despite a supposed abundance of water availability. This evidence for mixed approaches further underlines the importance of versatility in local agricultural systems and their underlying structures, favored and implemented by local communities.