|
<br />Presented on Table 3 is a summary of the known flood event, and selectedcharacterist ics
<br />of each stonn recorded. The information recorded on Table 3 has been compiled from
<br />newspaper accounts along with other articles.
<br />
<br />ImperviOllsArea
<br />In general. total runoff from a ";ater,bed is a function of the type of soils an dthe el<tent
<br />of impervioU!; area within the basin. RUn\lff curve numbers, which are based on soil types and
<br />impervious area. were determined for each sub-basin in the Monument Creek watershed for both
<br />existing and future development conditions. Curve numbers were calculated based on the
<br />prQ(;cuures idel1lifled in the City/C'oul1ly Drainage Criteria Manual. Tables 5-4 and 5-5 of the
<br />criteria manual wasrcferred to when sclecting representative curve numbers.
<br />The extent of imperviou, area within each sub-basin was estimated for existing
<br />development conditions based on aerial photography of the watershed dated November, 1989.
<br />Various land uses shown in the aerial photography were categorized according 10 the
<br />infommtion shown in Table 4. A work map was prepared indicating the location of each land
<br />use zone relative to drainage basin boundaries. Areas of the calegorized land uses within each
<br />sub-basin were measuredus1l1g aplal1lmeter.
<br />Sub-ba,in imperviousness for future developmel1l conditions was based on information
<br />prepared by the City of Colorado Springs. EI Paso County. and Pikes Peak Area Council of
<br />Governments for a recent planning study entitled "Socioeconomic Foreca,ts for Transportation
<br />Planning Beyond the Year 20JO". In order to develop the plan. the ultimate ho\dmg capacity (in
<br />term, of population and residential and busines~ density) wa~ estimated for a number of
<br />transportationplanningwncs. These estimates. developed to ensure that growth would not bo:
<br />
<br /> , -
<br /> , , = ,
<br /> "ji I, .. !l~ m ....!:.!j
<br /> g-:,~ i "' ,
<br /> !- ..,,'ij-l:
<br /> m >, ~~ "'. ," " ~,]
<br /> 0 c, jci.! " -] ,
<br /> . ,~~; 1!1>l . - ~~"
<br /> 0' .~ U <ll .10 ,~
<br /> .
<br /> ^
<br /> . "
<br /> 8i ~
<br /> ,
<br /> .!'l - .
<br />~ -
<br /> ~,
<br />~ >' > , ' > j
<br /> . ." H
<br /> I ~~ , ]~ ~N
<br />~
<br /> >-, 0 e;-:lolj.... n
<br />~i:l , z ." 0
<br /> 0
<br /> .
<br />~~8 . -.' " i
<br />301 _ , H . . j "-r !jg"
<br /> , 'N' hi '''J · ~p
<br /> g~= .!E '1!U <lil ., ."] .~~~
<br />~~ ~ - 0' 118 c.<] ] 'r
<br /> '~ > ,
<br /> < . ~ ~ ~l~~ " .,
<br />~" " > - . ~::E9 0 u . >
<br /> u . >> 0
<br />00 " ..9.51- ::E:" c ~
<br />~~ ^ ,
<br />"
<br />G ji8~ . 8
<br />~ - -
<br />~ 0 '"
<br />~ '0
<br />01-
<br /> ;;~ ..
<br /> m~ g g g g
<br /> . = = >(
<br /> ~ c: 3 ~ .
<br /> 8~u
<br /> . . ~~ . = , .
<br /> ~ ~.~ = .
<br /> , "
<br /> "< " .
<br /> - N . g
<br /> 0 - 0 . - . ... -
<br /> ~o ,. "< N. N' ;~ .,- -!i: ~, --
<br /> NI;; ^' >' N _ " ..
<br /> " -' -- ;- ~ :!: ,.,~ ."c_
<br /> ,- >.- .- o- r ,- 0-
<br /> , . N
<br /> N , N - -
<br /> . -
<br /> '--
<br />
<br />Soils and Geolol!y
<br />Soils within the Monument Creek basin vary between soils types A through D. as
<br />identifictl by the U.S. Depanment of Agriculture. Soil Conservation Service. Type D soils are
<br />predominate in the forested areas west of Monument Creek. These soils are generally associated
<br />with the Pikes Peak Granite found in the region. Figure 3 depicts the hydrologic soil types
<br />distributed throughoUl the Monument Creek basin.
<br />Soils are classified in hydrologic groups A, B. C. and D according to their infiltration
<br />capacity. Group A soils consist chiefly of weU-drained sands and gravels and have a low runoff
<br />potential. A work map was prepared showing the distribUlion of the four soils groups throu ghout
<br />the Monument Creek watershed. The percentage of each soil group within individual sub-basins
<br />was estimated by using a planimeter to measure soil group areas.
<br />
<br />1II-6
<br />
|