Laserfiche WebLink
Technical Review Guidelines for Gravel Mining &Water Storage Activities <br /> The top widths are expressed as the distance between the top of the riverbank slope to the top of <br /> the pitside slope. The area between these two tops of slopes should be no steeper than 3 percent <br /> and as a minimum have a stand of vegetation that resembles the native vegetation along the site <br /> with reasonable closeness. <br /> 2.6.1 Existing Unstable Alignment <br /> When the river is allowed to maintain an existing unstable alignment, and no bank protection is <br /> provided beyond the necessary revegetation, the minimum allowable top width of riverside berms <br /> will be 400 feet. This is the maximum setback requirement imposed on gravel mining operators. <br /> When the river is maintained in an existing unstable alignment and the riverbank is protected in <br /> accordance with the requirements of Section 2.3—Riverbank Protection, the minimum allowable <br /> top width for the riverside berm will be 250 feet. <br /> When the river is left in an existing unstable alignment and no riverbank protection is provided, <br /> but pitside slope protection is provided in accordance with the requirements of Section 2.4— <br /> Pitside Bank Protection, the allowable minimum top width will be 300 feet. <br /> When the river is maintained in its existing unstable alignment and protection is provided for both <br /> the riverbank and the pitside slope in accordance with Sections 2.3—Riverbank Protection and <br /> 2.4—Pitside Bank Protection, the allowable minimum top width of the riverside berm will be 150 <br /> feet. <br /> 2.6.2 Master Plan Alignment and Minimum Maintenance Alignment <br /> The Master Plan alignment and the minimum maintenance alignment are two cases in which the <br /> alignment of the river is predetermined and riverside bank stabilization is provided. The Master <br /> Plan alignment is mostly a modification of the existing alignment and is intended to reconcile the <br /> geometric requirements, property line constraints and constraints imposed by the existing river <br /> alignment. <br /> Bank stabilization for the Master Plan alignment and the minimum maintenance alignment will be <br /> in accordance with those methodologies presented in Section 2.3—Riverbank Protection. For the <br /> Master Plan alignment, the various acceptable types of bank stabilization are presented in the <br /> Master Plan drawings and differ slightly from the requirements specified in Section 2.1—Types <br /> of River Alignment and 2.2—Revegetation of Berms. The principal differentiation is in the <br /> required stabilization scheme. <br /> When the requirements of the Master Plan alignment or the minimum maintenance alignment are <br /> adhered to and, in addition to complying with the requirements for river bank stabilization, the <br /> pitside slope of riverside berms are stabilized in accordance with Section 2.4—Pitside Bank <br /> January 2013 Urban Drainage and Flood Control District Page 24 <br />