ZIMMERMAN RESERVOIR. Zimmerman Reservoir was near the Pecos River five miles southwest of Imperial in northern Pecos County. About 1908 the Zimmerman Land and Irrigation Company began construction of the reservoir, which was built to provide irrigation water along the Pecos River and promote land sales. In 1942 Zimmerman Reservoir was destroyed by floodwaters and was not rebuilt because of the great expense involved. The lake was in an area characterized by gentle slopes, variable soils, and vegetation consisting primarily of scrub brush and grasses.