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<br />advantage in that a certain amount of.s election is poss ible <3,nd the m.ore <br />heavily ladert flows may be bypassed. It is also .often possible to provide <br />a sediment trap above the off-channel pond (Talbot, 1943). <br /> <br /> <br />001528 <br /> <br />Livestock in the Southwest tend to graze into the wind, (Allerd, <br />1948). This can cause the windward side of a pasture to be over-grazed. <br />Placing the water supply on the leeward side will aid in overcoming such <br />abuse. Other factors being equal, watering places that'can be reached <br />from numerous directions should be given preference. Rapid and easy <br />dispersal of livestock following their drinking relieves congestion and <br />trampling (Hamilton, et al., 1940). <br /> <br />it~ <br /> <br />~"~,~,'~l <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />,w:~~~ <br />(~.~;.~ <br />~::~~:',.<,:: <br />!~~~fl <br /> <br />.;:.}:;~;;:~: <br /> <br /> <br /> <br />).~'<?t: <br /> <br />Sedimentat ion depos ition in stock ponds over most of the Southwest <br />is inevitable where there is sufficient runoff to justify construction of such <br />ponds. The amount of sedimentation will depend on soil composition, slope, <br />size of drainage, vegetative cover and amount, duration, and intensity of <br />the storm (Peterson, 1961). The rate of deposition can vary from time to <br />time, due to changes in factors which affect erosion on the watershed, <br />particularly changes in extent and effectiveness of the vegetative cover. <br /> <br />It is generally recognized that in the arid and semiarid regions, <br />areas with southern exposure and sparse vegetation have the highest runoff <br />for a given amount of rainfall. These same areas commonly produce the <br />most sediment and the least forage and should therefore be accorded all <br />pos sible protection. Where conditions permit, ponds in watersheds'with, ' <br />southern exposures should be located so as to serve areas with northern <br />exposures having better forage and less runoff. <br /> <br />There are areas where it may be economically feasible to build <br />ponds with the dual purpose of furnishing stock water and erosion control, <br />such as the filling of gullies. In these instances, new ponds can be con- <br />structed as the older ones fill, the ,added expens e being justified on the <br />bas is of erosion abatement and range improvement. <br /> <br />While it is generally poss ible to estimate the average sedimenta- <br />tion rate in a grou,p of stock ponds in the same locality, still each po,nd <br />site presents an individual problem relating to both hydrology and drainage <br />bas in characteristics. Rec ent studies by Hadley and Schumm (1961) in the <br />upper Cheyenne River Basin tend to indicate that sedimentation predic- <br />tions can be made within usable 1 imits when certain factors relating to <br />the drainage basin are known. Speaking of one factor, the relief ratio, <br />they state: <br /> <br />"The correlation between mean annual sediment accumu- <br />lation and the relief ratio suggests that a practical approach <br />to an erosion classification of land similar to those in the <br /> <br />;~~\~;~ <br /> <br />~;':;:-:~>~~;::; <br />,-"'." . <br />. ". <br /> <br /><;:..~~(:::< .:".: <br />: .:- .;~;;" -';.;. -.: <br /> <br />;.-.,,:'. <br /> <br />38 <br /> <br />,';',:";," <br />:""-"_." <br />,., ..' <br />::.':'.j:"-~:.'.;' <br /> <br />, " <br /> <br />-.;-;--:.,,-,.;.. <br /> <br /> <br />i///',J;1;f;t!j <br />. . .;,,~ '-, . .';_ . ',', 0 <br />