Laserfiche WebLink
<br />~ <br />00 <br />c <br />M <br /> <br />c <br /> <br />structures were installed to control water apportioned to the <br />Havasu National Wildlife Refuge. <br /> <br />~ <br /> <br />Topock Gorge Division (Topock to Lake Havasu) <br /> <br />Before river stabilization work was begun in the Mohave Valley <br />Division, heavy deposits of sediment were laid down in Topock <br />Gorge and in the upper end of Lake Havasu. While the high-water <br />conditions that existed in Needles prior to 1951 were being <br />corrected, it was recognized that sediment deposits in the Topock <br />Gorge Division were an important factor leading to high-water <br />levels existing from Topock, Arizona, north beyond Needles, <br />California. <br /> <br />It was recognized that channel dredging of the river in the <br />Topock Gorge Division would be required. In October 1967, a <br />plan was approved and work begun. In June 1968, however, the <br />work was suspended after about 1.7 miles of the upper gorge had <br />been dredged. <br /> <br />Havasu Division (Upper Lake Havasu to Headgate Rock Dam) <br /> <br />This division, covering all of Lake Havasu, includes the river ~.~~ <br />between Parker and Headgate Rock Dams. Because of the lakes -, <br />formed behind the dams, little need has existed for work on <br />the levee system in this division. <br /> <br />Parker Division (Headgate Rock Dam to Palo Verde Diversion Dam) <br /> <br />Many reaches of the river in the Parker division are subject to <br />bank erosion, meandering, braiding, and (particularly in the <br />lower part of the division) sediment deposition making the river <br />shallow, unstable, and generally of marginal value to water- <br />oriented developments. River flow has caused large quantities <br />of sediment to be transported downstream. Until a sediment <br />trap was built below Imperial Dam, eroded materials were deposited <br />in Imperial Reservoir or handled through the All-American Canal <br />Desilting Works. Sediment sampling records indicate the Imperial <br />Reservoir now traps approximately 50 percent of the sediment <br />load, with the Desilting Works and the Lagune Settling Basin <br />removing the remainder. Channel improvement work (made urgent <br />by growing land development between Headgate Rock Dam and Alli- <br />gator Bend) was completed in 1967. The river was stabilized by <br />confining overwide reaches of the river between training <br />structures placed on stabilized banklines. Several miles of <br />levee has been constructed above Palo Verde Dam on the Arizona <br />side to protect adjacent Indian lands from flows of up to 80,000 <br />cfs and is in good condition. <br /> <br />D-2 <br />