Laserfiche WebLink
<br />Table 3-3. Existing yield summary. <br />Problem Area Annual Yield (tons) <br /> <br />Mean Daily Load (tons/day) <br /> <br />11 <br />l5 <br />83' <br />l75 <br />130 <br /> <br />3 4, 1 00 <br />4 5,600 <br />5 30,200' <br />6 63,800 <br />7 ~~OO <br />, Average of above and below diversion values. <br /> <br />causes scour and deposition and inhibits effective conveyance of water and sediment. Third, <br />the sediment transport potentials along the river area are erratic as well. Even with the <br />approximate methods used in this study, more uniformity and clearer trends would have been <br />expected. <br /> <br />The charmel appears to be largely impacted by three phenomena: a reduction in peak <br />flows due to the upstream reservoir, changes in the vegetal makeup of the floodplain, and <br />agricultural encroachment. The reduced peak flows cause the channel to become smaller. This <br />shrinkage is often exhibited as narrowing. Vegetation moves into the newly formed bank and <br />inhibits its widening again during high flows. Likewise agriculture moves closer in and <br />functions in essentially the same manner. Reduced peaks induce the sense that the river needs <br />less room. In much the same way this encroachment inhibits rewidening of the channel. <br />Additionally, leveeing further restricts the flow path and causes incision and bank instability. <br />The battles are fought, sometimes at considerable cost, and the river responds with further <br />instability. The cycle continues and the effective capacity becomes less and less. <br /> <br />GroundwaterlSurface Water Interaction <br /> <br />Over the course of the study, many landowners indicated that surface water flooding <br />from the Arkansas River was a secondary problem compared to saturation from groundwater. <br />While groundwaterlriver flow interaction is outside the scope of this study, some qualitative <br />discussion is offered here because of its relevance to recent events and the operation of John <br />Martin Dam. <br /> <br />Groundwaterlsurface water interaction is a natural, dynamic process influenced by <br />many variables which change over time. The simplest way to illustrate gross interaction is to <br />consider the relative elevations of both the groundwater and river water levels at a given point <br />in time. If the two water level elevations are the same, they will remain this way. If the river <br />level is lower than the nearby groundwater level, they will attempt to equalize through transfer <br />from groundwater to river. Conversely, if the river level is higher, the transfer occurs in the <br />opposite direction, and this is the case that will be discussed further. <br /> <br />24 <br />