For as long as agriculture has existed in the Central Valley, farmers have pumped water from the ground to sustain their livelihood and grow food consumed by much of the nation. This has caused the ground in certain places to sink, sometimes dramatically, eliminating valuable aquifer storage space that can never be restored. The damage by subsidence extends to the California Aqueduct, the 700-mile artificial river that conveys water from Northern California to the valley and beyond as the principal feature of the State Water Project. The recent drought only intensified the problem.