<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).
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<br />001528
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<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).
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<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.
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<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:
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<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
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