WSP10994

• File Number: 8210.470
• Description: Pacific Southwest Interagency Committee
• State: CO
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 3/1/1962
• Author: PSIAC
• Title: Stock Water Facilities Guide - March 1962
• Water Supply Pro - Doc Type: Report/Study

001503

compaction, but care should be exercised in this practice to confine the
animals to the collecting ar ea to prevent damage to the adjacent range.

With removal of vegetation, the compacted area will be subject to
erosionfrom both raindrop impact and overland flow. The most effective
protection against this action is afforded when treatment to secur e maxi-
mum density and compaction is applied to the surface layer leaving it both
hard and impervious. This can be done through us e of pneumatic tampers
on soils having optimum moisture content. Even with best treatment,
however, the compacted areas will be subject to gradual recovery of infil-
tration capacity and increased erosion and periodic repa-irs and poss ibly
occasional renewal 0 f the treatment will be needed.

A number of ,chemical compounds are used as dispersing agents
but for areas of the size needed for runoff purposes, ordinary rock salt
is probably the most practical. To be effective it should be applied at the
rate of about 1 pound per square yard to areas having a fine textured
clayey soil. As the salt has no effect until it is dissolved and the soil
particles are saturated, a good wetting of the area by rain or by artificial
sprinkling of water is essential for best results. Nonwetting silicones
have been developed in rec ent years, but as yet not enough is known con-
cerning their performance and cost to determine if their use for increasing
runoff is fea.s ible.

Some increase in. runoff is being obtained through vegetative modi-
fication attributable in part to the reduction of losses from interception
and in part from a reduced volume or chang,e of vegetation. In most range
lands any increase is likely to be minor and modifying vegetation for the
sole purpose of increasing runoff will seldom be practical in small drainage
areas. However, it could be in importance in large drainage areas.

Paving drainage ba;;;ins

Compaction and rela.ted types of land treatment can be expected
to increase runoff by only a nominal amount. The nature of the treatment
leaves the land in a condition such that varying amounts of precipitation
are st ill absorbed, particularly dur ing small or low intens ity storms.
Pavement, which approaches complete impermeability and eliminates
most surface detention, naturally give a much higher proportion of runoff.
Also, it usually is much higher in cost. Asphalt membranes or soil and
asphalt mixes have commonly been used for this purpose, but soil cement
mixes and gunite may also be cons idered as pos s ibilities. Recently devel-
oped plastic membranes can now be installed at prices competitive with
other ty,pes of pavement. Information on each of the methods is available
from the manufacturers and distributors.

12

'-'/;!:,

(~~~

:';;_:'~~:; ;:~:I~

:~,~j~;:I~~
,:~;",'- ...~;,:
'~+~" :~,
~:....<~.~:;~
';~:1'ft

-:.,'-.';<.:-:;.
'.'..."..
;},t"\,.\\

i~"~'~<~;
t~~0g~)
N~\'\:~
i~:;111~::;:
;, .~::!?~;~~

i
.;~lik'r~

;<,::~\;;.;;.-;'
:'~_~n1/Y;
}'_<~}.:~'::-'i

I

-:-.~/~:r.
. ,'- .;'';
, < :; ';:;;'- ~.
;~:'::;~~~~?;Jt

'.~ - ;~..:

,~, .~.:

,."..;
,:,. '-;:~;'<'<'
:.~~.:~;~~;: ~<

'. -'.
. :',',

'''';''.,

'-.' -,

:.~.; -':.,".;;".

....;.

.:';;--.,.:

"
<;".; .->.':. .,;~
".'.

", :~':" ~:<