Laserfiche WebLink
<br /> <br />Housing development and drainage alterations caused this <br />accelerated erosion near Golden. <br /> <br />Aggravating Circumstances <br /> <br />Man's act i vi ties great I y in f I uence the rate and extent of <br />erosion and deposition. Stripping the land surface of <br />vegetation, altering natural drainages, and rearranging the <br />earth through construction of highways, subdivision <br />development, farm land preparation, and modification of <br />drainage channels for water control projects are significant <br /> <br />factors in increased erosion and deposition. All the <br />geo I og i c processes wh i ch make ava i I ab I e more mater i a I for <br />erosion and deposition tend to increase the rates of each <br />process. This is particularly true for landsl ides, mudflows, <br />debris flows, earthflows, rockfalls, and physical and <br />chemical weathering. These processes also involve erosion <br />and deposition whi Ie frequently making more material <br />vulnerable to erosion. <br /> <br />Mitigation <br /> <br />The processes of erosion and deposition cannot be stopped <br />totally, They can be reduced and controlled by surface <br />drainage management, revegetation of disturbed lands, <br />contro I ling stream-carr i ed eroded mater i a Is in sed i ment <br />catchment basins, and riprapping of erosion-prone stream <br />banks, especially adjacent to structures. Understanding <br />these processes and taking preventative action can lead to <br />development and land-use methods which minimize losses. <br /> <br />Land Use <br /> <br />Ordinarily, erosion and deposition do not curtail land use, <br />especially if efforts are made to minimize them. <br /> <br />Case Histoty <br /> <br />Near Larkspur in Dougl as County an access road and shallow <br />borrow ditch were cut to serve an airport runway uphi II from <br />the access road. During construction of the road and borrow <br />pit a large area was stripped of vegetation. Heavy water <br />runoff from above the runway and the runway itse I f was <br />channa II ed down the borrow ditch. There were no contro I <br />features to slow the velocity of the water or retard erosion. <br />ilithin five years the borrow ditch was eight feet deep, <br />Properly designed and Installed water control structures, <br />revegetation of the graded area, detention ponds, drop <br />structures, and other measures wou I d have pa i d for themse I ves <br />in later maintenance and repair costs. <br /> <br />13 <br />