The most important irrigation water source in Kansas is the High Plains aquifer, which recharges very slowly and has been steadily declining over the past three decades. A common policy prescription for conserving groundwater is to encourage the adoption of more efficient irrigation technologies, which have higher water application efficiencies. In Kansas, such a policy approach has already been implemented through cost-share programs. Although conserving water is the stated justification for such a cost-share program, its effectiveness is questioned. There is substantial controversy and conflicting evidence in the empirical literature on the conservation effects of technology. The conflicting results have likely come about because the processes driving the observed changes are highly complex and dynamic in nature. The purpose of this study is to examine the interactive and dynamic relationship between groundwater levels, crop selections and irrigation technology investments, which has so far been addressed separately or statically. The main objective is to examine whether the cost-share program is effective at conserving groundwater.