In 1985, Kansas filed suit against Colorado alleging they had overused their share of water outlined in the Arkansas River Compact. For the next 24 years, Kansas spent over $20 million and 250 days in trial to convince the US Supreme Court that Colorado violated the Arkansas River Compact. The courts found that Colorado had indeed depleted flows to Kansas through their development of groundwater pumping installed after 1949. In April 2005, Kansas was awarded $34 million in damages and $1 million in legal costs. Then in March 2009, the final document was issued, requiring the use of a hydrologic-institutional model to bring Colorado to compliance.
