HomeMy WebLinkAbout79 - 107 A (8)CONTENTS' (Con Llnue;(l
TABL-rs
Storm..D,-ai.nage Design Criteria
-1
Des'911 Channel IMprovomenta ......
2-1.0
11-2
Drainago Structures .......#0 ,
2-14
11-3
Construction Cosi: E$tima,te .. .
. .
2-16
11-4
Project Cost Summary .. ..
Tr1-].
Diversion Channel. Improvements ..
3�
111--2
Natural Channel. Improvements ... , .
3-7
111-3
Drainage Structures .......... I ...
3m -ll
111,1
Construction Cost Estimates ......
3-16
0
111-5
Project Cost Summary ........
3-20
PLATB8
URPOr Mud Creek: Plan 2•iap .. ......
1n Pocket
Mo idian--Munjar Plan Map .........
11 Pocket
rlcurts
1-l.
Location Mai . ,
i
1-2
P,laciPitataon Intensity -Duration -
Frequency , .............
.. ..
1-0
11-1
a.cal. Channel. Sec•La,ot�� ....
Typical Sections
11-2
Co I!GctiOn �Ianii olc�
.......... .... ,
2-S
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..
DESIGN AND PLANNING CONS IJ%RA', aONs
for the
DEVELOPMENT CR STORM -DRAINAGE IMAGE FACILITIES
in the
UPPER MUD CREEK ARRA,
and the
MERIDIAN-MUNJAR AREA
of
Butte County, California
PART I
INTRODUCTION
-Location'
The study area of this blaster Storm-D,ra nago Plan is located
northerly, of the City o£ Chico in Butte County, California,
about l� to 7 miles south of Tohama County (,refer to
location map) It; is situated on the floor of the Sacramento
River Valley at the base of the foothil,l:s of the Cascade
Range and encompasses two separate,major project areas.
One, the Upper Mud Creek area, ,is generally bounded by Rock
Creek to the north, sycamore Creek to the south, State High-
way 99E to the west, and the Chico Municipal Airport to the
east. The other, the Meridian-Muhjar area, is located to
the north of Rock Creek and the Upper Mud Creek area. These
two project areas 'comprise _a total combined area of approx-
imately 4,1.00 acres (0_4 square miles).
— Purpo:ne & 8ccapo
'Clic study ,areas'; of this �zaster plan have ))(,on subjected ,to
only minor drainage planning in tt e east, and long-range
drainage plarining has been virtually non-oxintent.
The Upper Mud Creel, area hat. been 'targeted for extensive
V)
..residential
residential develapmont, and attondant access roads will
require storm-drainacje facilitieo. Urainac7e in this area: is
complicated in that Keefer Slough is the only natural d.rain
of- note, and it receives flood --eater overfloi�� from Roc%
Creek via a natural stream bifurcation. Additionally, due
-to agricultural land -leveling activities, Xcefer Slough is
practically non-existent westerly of Highway 99E; and
Sycamore Creek and ,Mud Creel,, have been incorporated into a
flood -diversion project, with the resulting levees and
elevated floodwater conveyance serving to limit natural
drainage opportunities for tributary lands.. Finally, the
Pattern of existing development has severely limited many
opportunities for, implementing storm -drainage facilities,
frequently dictating that less -desirable options and align-
ments
i.ic, n -ments be adopted.
The Me.a idian-munjar project area is poorly equipped with
either natural or artificial ',storm -dr ainage :facilities,
frequently posing problems to the public health and safety
with respect to access and sewage disposal. This may be
evidenced by the numerous "notices 01: violation" historic-
ally
i:torically imposed on many of the parcels in the area.
The purpose o:� this Master Storm -Drainage Plan is to
provide a systematic and orderly approach for the eventual
solution of existing and future storm-rinduced runoff problems
within the ultimate development plans for these areas. Tho
Provision of sufficient flexibility within the framecaorkl
l-2
of 1*110 blastor Plan is a, necassary premi.�c, as the gill,_11
improvemont8 realizad will most certainly be a hybrid o;C
9
the proposed facilities. Accordingly, the recommendations
oi: this -Plan should be considered as conceptual, for
plannJng purposes, vith, the preliminary -design ;features
being subject to z„,o 1 ificationS recommended by final
facility dosgn�
The scope of thl.l Master Storm -Drainage Plan includes the
following:
... the development or design criteria for planning
and design of storm --drainage facilities within
the project area boundaries
the selection of a hydrologic method for determ-
ininU peak storm --drainage discharg0s, at various
frequencies;
... the Preliminary design and layout of major
outfall channela and interceptors required to
:verve the project area, within the constraints
of budgetary considerations;
the preliminary design and evaluation of major
drainage structures required to implement the
I,
proposed .Plan;
.. the development of cost estimates for the
construction of the proposed facilities,
•.. the establishment of a project staging schedule;
... recommendations for a preliminary assessment
program required to provide a means of funding
proposed improvements.
Accordingly, the provisions of this MAa,3t ez Plan
I proviinclude a
basis for the development of a storm -drainage network:, as
predicated by the ultimate land --use character. envisioned by
exiting or proposed Zoning (i.e., the contemporary chico
1\Irport Environs Rezone proposal) . This Storm -drainage
networyc includes tentative alignments, and proposed channel,
and structural configurations for these alignments.
l-
is
11
a
EI
- Description of tho Area
, 11 d d
There are two distinct and oaparatc,- project Ztrcat ; i clu 0
within the scope 09 this maoter Plan. Vic two projeCt
areas combined consist of approximately 4,100 acres (644
square mllefl-
The first, area, known as the Upper mud Crack area, is
located to the south of Rock Crack and to the north or,
Sycamore Creek, and is generally center ed about the upper -
valley reach of Mud Creek. This area comprises about 3,000
acres (4.7 square milcs)A it is currently in the early
phases of- transition from a modium-valUe agricultural land
use character, to one of low-deioity residential, with.
several isolated subdivisions of note currently existing.
The Upper mud Creek area is also the subject-, of a major
rezone proposal (as of mid -1979) which gonorally envisions
low-donsity and very -low density reoidontial development
(i.ei; one -acre minimum parcel$ s.nd larger). To the east
of this area is the Chico Municipal Airport and a planned
future industrial park, with some access roads to be level"
oped :Crom within the Upper Mud Creek area,.
This area of the Plan ranges in elevation from 165 to 230
feet above mean, sea level. Topography is gentle, typically
between r to 1 %. Natural drainage courses are limited.to
Reefer Slough, and to the north, in part, Rock Creek. Mud
Crook and Sycamore Crook have been developed into leveed
f-lood-control channels that essentially eliminate natural
crainage from adjacent lands .
Soil types in thisarea are extremely diverse, and are gon-
er t, 1 ly composed of irregular areal distributions of Tuscan
stony-.rlay lotm' Anita clay loam and clay adobe (categor-
"
0 ized in Plydroloqi.0 Group: D by the $o�itl Conservation Servite);
1-4
0
Vina shallow -M, loam (Hydrologic Orotat) C) ; tind vinirl loam
or clay loam (Hydrologic Group 13). Tbeae soilo have highly -
variable intiltration rates and infiltration capacities,
ranging from poor to moderately good.
The second area, known as the Meridian-Munjar area, is loc-
ated to the north of Rock creek and the Upper mud Creek area,
and compri5eo approximately 1,100 acres (1.1 square mile')..
it is a region notorious for, and conceived by, illegal
Obootleg'! lot splitting in recent ye -ars past. The area is
typified by parcels of 5 to 20 acres in size and is current-
ly zoned for 10 -acro minimum parcels. The clandestine
nature of development in the area has effectively pre-empted
any measure of public control and/or engineering input with
respect to access, dr',,inage, or subdivision design. Accord-
inqly, numerous problems currently exist in thir, area.
Previous to the lot -splitting activity, the Meridian-blunjar
area iqjs open space with some use as seasonal grazing lands.
This area is located on an alluvial fan and ranges in el
ati6n from 190 to 280 feet above mean seta level. Topography
is gentle, averaging, about 2% in slope, with n,atura.L drain-
age provided by numerous, poorly-def-ined swales.
Soils are typically of the Tuscan series, comprising stony -
and gravelly -clay loams, with some.expo8ures of clay-loams
and adobes of the finita series. These soils generally have
low to very -low infiltration rates and are categorized in
I-Iydtologic Group D by the Soil Conservation Servico. The
gentle topography, in conjunction with the poorly -drained
soils of low-inEiltkation capacity serve to sustain numer-
ous, small vernal ponds in the area.
13u�3c,��:taa:y a'�:i,1t1a.4:iL•a.c)�.1
The areas subject to this Master Plan and in
Particular the
Meridian-munjaz area, frequently involve
large expanses of
relatively low -value acreage, resulting in an extremely-
limited
xtremely -limited tax baso for financing public -Work l !n'J)rovamen ts.
This :financial constraint is in engineering parameter that
must be inhorently .recognized and incorporated in storm -
drainage facility planning, This constraint subsequently
necessitates the employment of minimally -accept able design
standards and a 'naximum of inovation ill order to further
cost effectiveness and a financial.l.y.-viable project;.
Accordingly, opon-channel drainage facilities have been
adopted. as the rule, as opposed to the more costly closed -
conduit approach. Similarly, the need for additional
drainage structures and appurtenances (bridges, major
culvert, outfall channels, etc.) has been minimized, if,
and wherever Possible without endangering property and
public safety.
C.X TMATOLOCY
General
Who climato of this area is frequently clan sifted as Mild;--
Mediterranean/War;m-summer which has two predominan-t
seasono the long, hot summer; and the mild, rainy winters..
Average-daily minimum and maximum temperatures range from
35 to 54°I" in January, to 60 to 980 in July, with the aver-
age-annual temperature being abort 62oF The froot-free
growing season averages about 234 days, and the average-
annual degree--hoa:ting index (6.50r base) is about 2800. U.S.
Weather Bureau Class-A pan evaporation amounts to app;ro :-
imately 65-70 inches per year, with about 75% Occuring during
the warm season of May through October. Mid--afternoon
relative humidity will typical,l,y range :from 75% during the
winter, to 20 during the summer.
Precipitation
The study orea recoxves an average-annual precipitation of
approximately 23 inches, almost all of which occur;, as
A
rainfall during the November-April rainy season. snow and
sleet typically constitute an extremoly-minor portion of the
precipitation regimen, existing in only trace amounts during
an avert-ge winter., Iioviever, a rare climatic occurence in
January 1937 resulted in a daily snowfall of 9.0 inches and
a monthly snowfall: of 1.1.0 inches to be recorded at the
U.s.B.A. Bxperimental Station near Chico.
Two predominant and separate precipitation regimes prevail
in this oreaa the thunderstorm; and the frontol. The
.thunderstorm (or convective) precipitation regime is'prev"
alent during the summer and: early fall. it is typified l:)yy
veerhiZi oint
y- g _ p intensitic,e, coupled with short duration,,
:and duo to a limited areal extent, low volumes of pr ecip-
l-7
itatiOlI. The frontztl (Or cyclonic) precipitation rogime is
provalont during tile winter and is typified by lower
int-on:ities than that of the thunderstorm regime, but with
much longer durations. Due to the large areal extent of
frontal storl"t.5, and the marine moisture source, net precip-
itation volumes are relatively largo.
Pt Ocipitation intens"it
y-duration"froquzicy relationships
were developed for the project area pursuant to the method-
ology of the National Weather Service contained in NQAA
Atlas 2 - Volume XI, Czalifoxnia.:This procedure allows the
determination Of Point 6torm-precipitation intensities (or
depths), for a given duration, at a particular recurrence
interval. Those relationships are pre$
ontod on Figure 1-2,
The point -storm intens ties (or depths) obtained by this
method must be adjusted for areas th,
greater -in about 5
square miles, by Ipplication of a depth -area adjustment that
is depe,tident upon the particular duration solect;ad.
Hydrological Rtrimi-.cations
Climatological considerations particular to the hydrologic
and hydraulic design of storm -drainage facilities incltide!
1. The thunderstorm (convective) regime, with its
attendant high-intensity precipitation, is the
most 4jignificant regime for storm-dr.ainago events
attributable -to shortdurations (e.q. ; the hydro-
logical design of local collectors);
2. The frontal (cyclonic) regime, with its sustained
moderate -intensity precipitation, is most signifi-
c&int'fo3,- events attributable to longer durations
(e.g.; for outfall channels and receiving streams);
3- Synergistic storm-runOfif regimes attributableto
intense rainfall with froten-ground condition , s ar, d/
or warm rains Oil, snowpack accumulations are not a
design coritiideration in this area;
4. Episodes of, anchor ice or aufois (shoot ice) forma-
tion in drainage channels or streams are rare to
non-oxistent, and 'need not be considered in the,
deaign of drainage improvements. Similary, the prob-
ability of, and hazards related to road -icing condi-
tions are relatively insigtificant for this area.
1-8
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It should be noted that design criteria are general guide.--
lines,
uide-
lines, and that specific circumstances may dictate the
employment of subjective adjustments for application in
particular situations (e.g.4 A low -traffic, minor road
structure night possibly be designed for a 50 -year event,
instead of a 10,.ypar event per Table 1-1, if it crosses an
open -channel interceptor designed for the, 50 -year event
andif the minor road provides the sole access for an area)4
1-10
DESIGN CRITERIA
The design critoria employed in determining the required
capacity of drainage facilities are second in importance
only the selection of •the hydrologic method to be 'utilized.
These criteria should be'developed based on an equitable
balance of allowable risk vs. cost effectiveness. Accord-
ingly, the criteria selected are an important storm -
drainage engineering parameter, regarding both design
adequacy and cost considerations.
In contrast to riverine flooding, storm drainage does not
generally posse major hazards to property, or to the public
health and safety. Subsequently, the use of more, frequent
events is appropriate. A review of the landuse proposed
for the area of this Master Plan, in combination with a
research of storm -drainage criteria in common usage,
resulted in the development of the design criteria present-
ed in Table No, 1-1.
It should be noted that design criteria are general guide.--
lines,
uide-
lines, and that specific circumstances may dictate the
employment of subjective adjustments for application in
particular situations (e.g.4 A low -traffic, minor road
structure night possibly be designed for a 50 -year event,
instead of a 10,.ypar event per Table 1-1, if it crosses an
open -channel interceptor designed for the, 50 -year event
andif the minor road provides the sole access for an area)4
1-10
TABLE, 110. X-1 -STORM--DRAINAGE
FACILITY DB814I N G.It.'l`;T.ERIA
Design I ocutrence interval.
Type of Dr7inoye Facility
0:)on Channel Closed Conduit
Local ROSidential Drains;
5 year 2.33 year
(up to 3-5 ecra:3
Local Commercial Drains::
10 year 5 year
(up to 3 acres)
Laterals (less than 30 acres):
10 your` 10 year
collectors (30-100 acres);
25 year 10 year
Outfa'lla or. Interceptors:
50 year 25 year
( over 1.00 acres)
Minor Road Structures:
0-1000 A.D.T.
10 year
1000-5000 A.D.T.
25 year
over 500`0 A.D.T.50
year
Major Rosa S'tructurezw
50' year
with capability to
withstand major damage at
100 vear
bridges & barge culverts
NOTES:
1.) Reduce criteria one ritop
to a 1oL;a"f-raquent event for
regions with minimum parcel
sizes.; of 5 acres or
gr ter ( except for major'
8tructum` )_.
2 • The 2.33 recurrence
)-year
interval event proximatitely
equ a1s the median 1torm-dral..Ylc1C
e event frequency.
3.) The :series
must be utilized for
recurrence interval," of 5
--years or 10036
111.
.
HYDROLOGIC ANALY8111
• General
The prediction of peak discharges in ungaged areas or in
areas involved in land -use modifications hao historically
been a difficult engineering problem. The loval cmployod to
predict pealt discharges has generally been, and remains,
predicated on thea value of the property to be protected and
Lhe consequences or- a failure. in this respect, Sturm
drainage again as contrasted with riverine flooding, general-
ly does not pose a major hazard to public safety or property
(excepting high-value commercial districts or districts that
provide emergency -public services). In this regard, the
major beneficiaries of storm-drainaclo facilities are typic-
ally roads and attendant traffic safety, minor property
protection, and the elimination or reduction of drainage -
related torts (legal actions).
Consequently, the trend it the hydrologic design of storm -
drainage improvements has commonly involved a zimpl' istic
and conservative approach, resulting in a commensurate
tendency toward facility overdesiqn. This inclination for
overdesign, when considered cumulatively, has probably been
a very --costly Practice. These problems can be avoided some-
what if careful consideration is given to the selection of
realistic hydrologic design data, as, with the exception of
design criteria, the prediction of a design peak -discharge
event is undoubtedly the single most important engineering
Parameter regarding both functional adequacy and cost effect-
ivenez's.
- Hydrologic Mtothoal'*
Procedures avoilable for dotermininq doaign peak discharges
are numerous, and gollertilly may be classified within one of
three major categories: information obtained from sytitem-
atic hydrological data -collection programs; hydrologic
simulation; and empirical modolio,.
Peak -flow information from data -collection proqrams are
essentially non-existent in this area as only limited dat,-,#
applicable to vory-large drainages, have been collected.
Such types of programs require that data be collected over
a subotantial period of time to be useful, (typically 10 to
25 years) and, except for some of the larger cities, do not,
generally provide a feasible or cost-effective approach for
storm -drainage desiqn. it is also difficult to modify such
data for land -use conditions other than that hat from what
existed during the particular period of collection.
Hydrologic simulation is an excellent technical method for
predicting peak discharges under most any type of existing
or proposed land-une conditions. Included among the numer-
ous hydrologic-aimvIation methods availablo are the: -
Stanford, Dawdy; Illinois Urban Drsinage Simulator; STORM.;
81-IMN; and SCS TR -20. While all of these digital -computer
models can produce excellent reoults for storm -drainage
design, they all have a common drawback -- cost of applic-
ation. Accordingly, such models were not considered for
this Master Plan due to cost consideration: and that, such a
refinement i,,,, generally not,, wztrrantod for, al plication to
drainage de sign in there 8emi-rui.-al/somi-u:rbnn areas.
Duo to the 1_-,roblams encountered with the cij�plicabiiity v
peal, flow data -collection programs and hydrologic simulation,
to this area, a reliance on empiricill models was necessary.
.1-13
- Empirical Models]
llumerotx, empirical models have been developed for oyntho5i.z-
ing peak:. -d ebarge data for storm-dr-ai,nage design purposes
Dawdy and Lichty (1968) suggo,ted criteria for 6olooting a
model for use in v particular application, (l) accuracy of
prediction; (2) simplicity of the model; (3) c:on.O.otenoy of
parameter estimates; (4) sensitivity of results to change:
in parameter values; and (5) the typo and availability of
data for the ,aubject basin. Based on these criteria applic-
able empirical models available for preliminary consider-
ation gore limited to the Rational Method and the approach
of the SGS TR -55 method. The Rational Method is the most
commonly --utilized method, but was ultimately rejected in
favor of the more sc ont-i fically-hasod approach provided by
the SCS TR -55 mothod, Doocriptions> and an evaluation of
these two methods are provided in the following discussion.
The R L-ional Mothou is also 3.nown locally .l as the California
Culvert Method, and in Europe as the Lloyd-mavis Method
Today, 17.13 years after its inception, it remain: the most
common method used in engineering design and application.
The Rational Miethod represents an accountant', npproach to
an engineering problem, in that Q -CIA whore Q is the
instantaneous peak discharge, l is the design precipitation
intensity for the time of concentration of the basin, A is
the drainage area, and.0 is the basin runoff coeff-icient
of these input variables, only the dral.nage rtes and the
precipitation intensity can be reasonably and/or correctly
estimated. The basin .runoff coefficient and the time; of
concentration are very -subjective, parameters to determine;
furthormore, the actual design precipitation intensity is
dependent on the accuracy of defining the time of concen-
tration.
1-14
'
This equation i t referred to as the "Rational Method" 3impJ'y
because the unit; are dimennional.ly correct, The method is
Tactually more common sensory than correct, an numerous
assumptions must be satisfied, and with the exception cif
applications to small., paved areas provided with gutters, and
severs, theae assumptions arc nearly impossible to justify.
0
The 'popularity of the method is clue solely .Lo its simplicity
Of al)plication and/or a lack of more definitive methodsi
txperiencc generally indicates that it produces high to very
high valueo of peak discharge. !'Although con;scrvatively-high
41)
values are produced, these "safe's design dischTkxges are
frequently utilized at the expense of construction economy.
The development of the Rational Method is probably attribut-
able to the work of the Trish engineer, T.d. Mulvaney, who
in 1051 autlioxed the ,paper ( and the Rational method)
published by the Institution of Civil 'Engineers of Ireland.
it is interesting to note mulvaney's discussion of his
method in closing his paper, where he states:
.(it) I it, tolerably near the truth,, within
certain limits only for an average catchment
that is 'neither mountainy nor, very flat' and
that (with the Rational Mcthod) the hydrologist
has no faithful guide, that. >I am aware of, to
help him to a conclusion as to the amount of
the effect on the discharge due to each or all
of these conditions) he is, in fact, left to
que8s at the result after. all....
Consequently, this popular method was rejected for use in
the development of thiw Master plan, particularly due to
its notoriety a;or overdesign, which could inherently affcct
the financial viability of the project.
The Modified SCS Tit -55 Matho,d developed by the aoi.l Conser-
vation Service, U'S Department- of Agriculture,, as modified
by the California trigi:neer ng District, provides a concise
technique for estimating peak discharges from 8milill Crater--
r
Shads ift Cali;Cornia. This method was ultimately i3elect-*
od
Cor tion in the prepo,4"Li0ft Of this M,14)tor Plan duo to the
excellent results it produces in thio area, and due to
limitations inherent with the other methods investigated.
'he SCS IPR-55 Method utilizea input data of: drainage area:;
average watershed slope, maximum basin flow length; 6 -hour
and 24-hour precipitation depths (for the particular design
f requoncy) ; and the averago basin Runoff Curve Number,
which is an abstraction that accounts for the hydrologic
proper. ties of various soil -cover and land -use complexes.
These data are then utilized to determine several inter-
mediate parameters that are entered on one of -three region-
alized storm -regime curves, producing both a peak discharge
and a runoff volume for the basin.
The determination of a Runoff Curve Number might, at first,
appear to b a subjective procedure similar to the selection
of a "runoff coefficient' -- however, published values recog-
nize four major hydrologic -soil groups which may be Subjected
to 25 different land-u8c practices, each Of which may have
up to three hydrologic -cover conditions, Consequently, the
development of a Runoff Curve Number is tons idered to be
a relatively -objective, specific, and well, --documented
procedure.
The applicability of the modified SCS TIZ-55 Method (with a
minor adjustment for an exclusive Type Ia storm regime)
was subsequently verified asbeing appropriate for use in
this area based on several calibrations with local data.
These calibrations were performed for log -Pearson Type III
distributions for 10 -year and 25 -year peak discharges
developed from limited gagingdata at Gold Run Tributary
near Nelson (Drainage Area = 1.3 square miles) and at
Wyman Ravine Tributary near Palermo (.Drainage Area
sclunro Milo,-); and Cor the 50--yonr end 100 -year pqaj
dischorgoo ao determined rrom S--Hydrogropli aynthooi.,: reoulUL
developed by t110 Corp:.; of Bnginoor,,,� Xor Koefor b1ough
(Drainage Area 2-a square miI040
Thenars colibrationa re.,witc:d in the SCt3l TIZ-55 Method prQduc-
iI q clig}]'1ly-higho , I but I'1e7rly-per'Xoc L u"g r'coment for the
10 -your peak diochargoN at Gold Duty Tributary and. 1Jyman
Ravine Tributary (e.g.; 2.36 vs 225 cEs and 145 vv. 140 cf
o'
reopectively) . The calibration process also provided reaaon-
able agreement with the 25 --year }weak di , chargo for Gold juil
Tributary (nlaout 3Q;0 too high) and Wyman Ravino Tributary
(,-'))Out 10 a too low) . The calibration procedure applied to
Keefer Slouch indicated that the SCS TIZ--55 Method produced
result., slightly,-l.owor than, but comparable to results
obtained from S--Ilydrograph simulation with the 50 -year peak
discharge boing about 211% lower, and the 100.-yoar. ,poa:<
discharge boinJ about 5 ,,' lot -.ter. The 3o discrepancios are
minor, con,►id ring the orders-of--m4gnitudo involved, and
are generally within arrar limits commonly attributable to
actual measurements in flood hydrography.
1^1T
�i
I-ing, II.�ti'., and B ator E.F,.; 1963: ' Handbook of Hydraulics
-5th Edition; McGraw-Hill, New York, 13 sections.
Mulvaney, 'T.J.; 1851: on the Use of Self-Ragistering' Irwin
and Flood G7uges in Malting observations of the Relations;
of Rainfall and or Flood Discharges in 'a given Catchment;
Transactions.of the institute of: Civil Nngin.eers of Ireland
(Dublin),Vol. 4, lit. 2, pp. 1.8 et seq
Rantz, Saul E.,, 1971: Suggested criteria for Hydrologic
Design of Storm -Di; ai.nage Facilities in the yen Francisco
Bay Aegio ; Technical Report 3, U.S. Geological Survey
Open -File Report, 69 p,
ItFT'NItNN�'I
Butte County kjlanning Dep<artmonl.; 1979: Rezone Proposal
---North Chico Airport Dnvirons; l pl.
Bureau of Public Roads; 1.965: Ilydr. zulic Charts for the
selection of` iI.igliwrty culverts --Circular No. 5; U
Department: of Commerce, 52 p.
Bureau of Chemistry and Soils; 1925: Soil survey of the
Chico Area., California; U.S. Department of Agriculture,
39 p. , 3 p1.s.
Chow, Ven Te; 1959; open Channel Hydraulics; McGraw -Rill
New 'fork, 600 p.
Chow, Von Te (Editor); 1964; Iiandl)ook of Applied Mydro-
logy; McGraw-Hill, Now York, 29 sections.
Dawdy, D.It. , and Dichty, Tt.W . ; 1:960: Methodology of
Hydrologic Model Building; Inst. Assn. scientific Hydro-
logy Symposium Proceedings, pp. 347-355.
Dodge Building Cost Services; 1979; bodge Guide for .Esti-
mating public Works Construction Costs-=-BditL on Ifo. 11,
McGraw-Hill, Nevi, York, 204 p.
Hjelmfelt, A.T. , and ca,.,idy, J'.J.; 1975: Hydrology for
Engineers and Planners; Towa State University Press, Ames
210 p
I-ing, II.�ti'., and B ator E.F,.; 1963: ' Handbook of Hydraulics
-5th Edition; McGraw-Hill, New York, 13 sections.
Mulvaney, 'T.J.; 1851: on the Use of Self-Ragistering' Irwin
and Flood G7uges in Malting observations of the Relations;
of Rainfall and or Flood Discharges in 'a given Catchment;
Transactions.of the institute of: Civil Nngin.eers of Ireland
(Dublin),Vol. 4, lit. 2, pp. 1.8 et seq
Rantz, Saul E.,, 1971: Suggested criteria for Hydrologic
Design of Storm -Di; ai.nage Facilities in the yen Francisco
Bay Aegio ; Technical Report 3, U.S. Geological Survey
Open -File Report, 69 p,
I
Simon t' ndrew L 19 76: John
T,'iley & Sent*,, New York, 306 1).
Soil Conzervation Service; 1975: U):)), -in Hydrology for
Sm -all, Releane No. 55- U.S.
DQPnrt'nQnt of Agriculture, 52 Pi & appondicles.
Spenn AOrjociotes, 'Inc.; August 1970: Chico ijunicipa-I
Airport Environ8 Plan --City of Cjjiro Butte County,
Urban Land Institute, et al; 1975: Storm Water Management;
U.L.I.P Washington, D.C,, 63 p.
U.S. National Werithor Service - 1973: Precipitation -
r
Frequency Atlas Q:C the VIestern United States—volume XI -
California; N.O.A.A., 71 p.
TJ. i. C eatller DurOau', 1960- Climatological Summary for
Chico, California, No. 20"4; U.S. Department of -Commerce,
3 p.
llanielizta, Martin P.; -1978: Storm natet Management—
Quantity and Quality- Ann Arbor Science inc,
I , 383
V,'-aanancn, Arvi 0.; 1573: Floods from Small Drainage Areas
in California—A compilation of Peak Data 1958-73; U.S.
Geological Survey open -File Report, 260 P.
Ililsey & Ham tnginecrro 1958: Master Drainage ')Ian- I
North Chico Drainage Area, Butte County; 32 1).
T'IclterPollution Control Federation and the American Society
O;C Civil Engineers; 1970: Design and. cbnstrution of Sahi-
tory and Storm sewers"41anual of PracticeIqo. 9; W-P.C.F.f
Washington, D.C. 332 p.
CONCEPTUAL C01481DERATIONS",
This area encompasses approximately 3,000 acres of medium -
value bands proposed for development to residential uses
(on one -acre minimum parcoln) and limited commercial uses.
The only natural drain of major siqnificance for this area
is Keefer Slough, as Rock Creek -to the north is an ag, grad-
ing stream, which limits most drainage opportunities to it
due to adverse gr6des; additionally Mud Creek and Sycamore
Creek have been developed into leveed flood -control
channels, with only limited potential for zerving storm -
drainage requirements. in addition, the Keefer Slough
channel is practically non-existent westerly of Highway
99E, and it receives flood -water overflow via a natural
stream bifurcation from Rock Creek.
Bconomics and the financial viability of the Plan required
that the need for drainage structures be minimized, and
-that an 6pen-channel collection system be employed. Those
are both justifiable assumptions for planning purposes.
However, closed -conduit systems will possibly be the ult-
imate preference in some isolated locations, and additional
drainage structures will be required as road development
progresses in response to future residential expanzion.
Subsequently, and in the interest of economics, proposed
drainage facilities are generally centered about a substaft-
tially-improv6d Keefer Slough trunk" with an outfall channel
to Rock Creek. This option maximizes the utility and flow
capacity of -the existing bridge on Highway 992. It also
eliminates the requirement for additional structures on
Highwiny 99E and/or secondary outfall channels to Rock Creek.
Outfalls to Mud and Sycamore Creeks are proposed for areas
to the south and east that cannot be served by the Keefer
Slough trunk system (refer to Plan map).
2-2:
TECIIrYxCAL PJsn'I.'(1IZL OF THE YLAN
Type cal Channal Section
Standard opon-channel sections were developed to service the
majority of the area encompassed by this .Plan. These stand-
ardized channel sections wore selected for their c.apabilit-
;i,os -to provide :flow conveyance and hydraulic efficiency,
construction economy, maintainability,, and stability From
construction
erosion and scour. Local experience with these and similar
configurations has been favorable (i.• c. ; North Chico)., These
•typicwal channel sections aro shown on Figure 11-1.
Keefer Slough Design Discharges
The determination of design weak: discharges :dor locations
on the main Kcofer Slough trunk (i.e.; outfall channel, and
channel reaches b, BC, DEO BG, B11, BTI -1, 131-1- 3, etc. ) is
complicated in that ICeefei: Slough receive: floodwater ,over-
glow from nock Creep via a natural stream bifurcation. This
inflow surcharges the tributary Keefer Slough system with
varying quantities of floodwaters to a degree such that the
SCS TIS -55 ,method will not predict accurate values of peak
discharge for these reaches. This noCessitated that an
alternative method be developed for these locations.
Studies of potential bifurcation inflow, channel attenuation,
and ali evaluatioii of relative hydrographic bine-lag effects.
(due -to large differences in drainage areas), indicate that
an 7nnronriate formula (empirically derived) for determining
"IT
Figure ]I I
RIGHT -OF —WAY _ .
Ser -k-L icQ Road Fence
/
' Design
2 Minimum Water Surface
d 2 * 1 Original Ground
Surface
-- b ---a�
TYPICAL CHANNEL SECTIO
DIMENSIONS IN FEET
CHANNEL TYPE
b
d
w
SERVICE
ROAD
SETBACK
R/W
A
3
3
23
15
5
43
B
3
4
27"
15
5
47
C
4
4
28
15
5
-48
D
5
4
29
15
5
49
E
6
4
30
15
5
50
F
6
4.5
32
15
5
52
G
8
5
36
15
5
55
H ,
10
38
15
5
58
2-4
�rla or e
no 50- or !00-yoti r de.:ii(jn posa%,
di.v,chargc, in cfa, aL tno point
of interest;
200 cfS = .peak discharge copal. ilitioaof
the str«am bifurcation at the
Keefer Road crossing;
10 cfo/mi.lo = a bifurcation -inflow peal--atlen:-
uation rate (which includes
channel, wedge & prism storage,
peal: tran,slatory effect;, side -
channel storage, and infiltration
losses,
iii iles _ stream miles downstream fror;► the
bifurcation ca:ossing at Keefer
road;
Basin 0 ,= the 50 or 100 --year peak diacharge
determa:ned ,by the SCS TR -55 method
for the tributary drainage basin
(of which 75% is a component- of the
design peak discharge, Q* -- due to
hydrographic lagging of peaks),
and; is limited to a minimum value of 100;G of the Basin
determined by the SCSTIZ-55 methoci.
Outfall Cha;nnol
Construction of an outfall channel for Keefer Slough will
be required. Thi.8 reconstruction has been necessitated by
the obliteration of the natural channel fr,,oiTi agricultural
land -leveling activities, es, and will need to extend fon
cpproximately 8,000 feet from the existing Highway 99L
bridge, westerly to Roc),,. Creek: The current absence of a
Channel has caused numerous backwater flooding and pondage
problems along and about the highway.
n discharre for
ask
',�`l�ie 50 - ear roc.itrr_once- interval desig peak,
y
I e outf gill at Fiicjhway 991, ( Drainage trea = 2,950 acres)
is 600 cfs. The co»Current-discharge of Roc}'Creek at the
outfall terminus ,has been determined to be approximately
G, 700 cfs (an event approximately equivalent to the. 10-
i
_ 2e5
M
Yenr pot) -t dioQhtarga) . 11,11itj relatively.
high concurrent dicchw,*900 and the nb.sun(;o of --,iqniIgicant,
h,4rouliQ attenuation, r, quires '�,ho outfall ciin 1t1e3. to
have three separate a,*eaches.* a
, leve cd backwat.or roach; a
lOvOod tr4in$iti.onal, reach; and a partially-loveed normal.
flow reach. Specifics :for, .,,ijje!3 (1-0ith ,,:I .0j,
ij ap CI
"I channels and minim .Uttar '.ro, A. follows:
.3ackw oter Rea(*
Do.,Agn 00 cf-I
Depth vari(.s zrom 6.6 frau to 12.5 feet
Ch,�innel Ilidth = 28 foot tO baso.
Channel Slope = varies from Ci0046 to 040035
Length of Channel ::; 1,600 feet
Transitional Reach
164-00 to ;Sta. 30+00
I)Or3iqjn Discharge = 600 cfs
Depth = varies from 4.3 feet to Gi6 feet
Channel Width = varies from 25 :roet to 28 feet base
channel SIOPO = varies from 0.0035 to 0.0020
Length of Chnnnel = 10400 feet
Normal Flow Reach
Sta. 304,00 to 5ta. 80+00 uj Higbway 99B Bridge
Design Di8charge = 600 c:rq
Depth -- 4.0 I.oet
Channel Width = 25 feet Cj base
Channol Mope = 0.0020
Length of Channel = 5,000 feet
Levee -Reach
Sta. 0+00 i.� Rock Creek to S"t-a. 401.00
(includes all of backwater and transitional
reaches and a portion of normal florj reach)
Levee Height - varies front zero to 4.0 fact
(with minimal freeboard)
Length of Levees = 4,000 feet
FWAn
0
Oben-Ch anne I Colloc-tion ManiCold
An upon -channel collo tion manifold is proposed as an
integral feature of this Plan. This man!4-old. is to be locat-
ed immediately upstream of the existing Highway 9�B' bridge
on Keefer Slough and will maximize its utility. This mani-
fold can be appropriately considered to be a low-volmme
sump, thiat has been provided with only minor grade, in
order to provide a gradient for service of the C. -channel
area to the south. Xt will also provide a commensurate
improvement in the gradient and efficiency of the lower
Keefer Slough trunk and the A -channel trunk. A schematic
detail of the proposed manifold alignment is shown on
Figure 11-2.
The employment of this collection manifold will eliminatn
the necessity for -;in addlitional outfall channel, and
I.Dos,oibly, attendant drainage structures on Highway 99E.
The proposed manifold alignment approximately coincides with
that of existing Keefer Slough, serving to minimize excavot-,
ion quantities. Disadvantges associated with this manifold
include anticipated low velocities, which will prompt the
deposition of debris and sediment, increasing main teni-ince
costs somewhat; and the Lioceleration of flow through the
bridge, requiring additional erosion -control improvements
to be necessary. lioweVer, -these disadvantages are relatively
minor and this collection -manifold old option was determined to
Ise the most cost-effective 8olutioni
nr
M. ? ��'gN t�;w •Yfdyl"rCX "I �'a-:' v i w. ` iu l t`.- t r °.Y:'1h { '.i '4t . ��" {. i.
� •.Y a,Y{�a 1 ��; .Ile''"','1 w"1 ;�:/r F ria• t J* t r a t ';r ,f �'i• 1 r `' ..i4 �;��'�, � �1� � i ^�k'�-��� f s� 4 9 .� t t ty �� r ra �. � �.
4 I a v t 7/ '.,; •iy. n Y; �q P y N ! i �, 4 r i s q- Y e y Y
f�
w. o' •fit � �,y t� ti •{,
I
Drainage Cbnn,nol Sytem
A network of opon-channel collectoro and intorcoptozs
proposed for this Plan is generally centered about an
improved Keoger Slough trunjc, with an outfall to Rock
Creek; and 4-ivo outf-allo to Mud and $ycamore Creeks. This
0 network is delineated on, -the Plan map. Preliminary design,
recommendations for individual channel configurations are
summarized in Tnble XI -1.
This drainage network was developed following the general
criterion 'that all locations encompassed by the district
boundary are to be within about 1,000 feet of a servico
channel... Additionally, design soxvice arejc tributary to
each channel roach wore slightly overlapped. 111his was
necessary due to the relatively -flat topography ajid the
indoterminato drainage patterns obtainable from f-tture
subdivision activities.
Hydrologic design requirements for individual channel
reaches wore based on peak discharges determined for
frequencies pun.,,Uant to the design criteria section, and
for anticipated ultimate land -use conditions. Hydraulic
design was based on these hydrologic -design parameters,
available grade8, and the typical 'channel sectiono, of
Figure 11-1. In addition., a manning,8.roughness coefficient
of 0.030 (for maintained, ear -then channels),, and ndrm,.Il
steady -uniform flow conditions were 'utilized.
TABU
11-1
Dls"SIGN CIIANN)M
IMPROVEMENTS
Service
Peak
Proposed
Channel
Area
Recurrence
Discharge
Channel
Channel
Reach
(Acres),
Intoryal
(ars
Slope
Section
A
285
50 yr.
56
0.0912
A
AA
160
$0
30
.0012
A
AA-1
70,
25
10
.0012.
A
AA-2
55
25
7.5
.0030
A
AB
105
30
34
.0030
A
AB-1
55
25
15
.0021
A
B
2,300
50
513
.0022
H
8A
2.5
10
4.7
.0037
A
BB
280
50
54
.0052
A
BB-1
35
25
97
.0033
A
BB-2
230
50
46
.0040
A
BB-3
30
25
5.8
.0039
A
BB-4
175
50
38
.003,6
A
BB-5
25
10
2.6
.0067
A
BB-6
120
50
34
.0055
A
BB-7
65
25
14
.0055
A-
BC
1,970
50
480
.0022
H
BD
90
25
28
.0060
A
BD-1
35
25
14
.0060
A
13E
1,850
50
470
.0022
H
BF
250
50
69
.0041
A
BF-1
200
50
63
.0051
A
BF-2
14u
50
50
.0056
A
BF-3
80
25
29
.0038
A
BG
1,620
50
470
.0022
H
B1#
1,330
50
4,220
.0047
F
BH-1
1,160
50
420
.0055
F
BR-2
95
25
25
.0092
A
BH-3
215
50
235
.0055
C
BH-4
890
50
268
.0055
C
BJ
240
50
74
.0050
A
BJ-1
150
50
58
0071
A
BJ-2,
40
25
8.5
.0003
A
C
320
50
67
.0004
B
CA
145
50
34
.0020
A
CA-1
70
25
21
,0020
A
CB
150
50
38
.0012
A
CB-1
70
25
19
.0010
A
D
345
50
105
.0007
C
DA
145
50
57
.0007
B
DA-l;
95
25 ,
36
.0007
A
DA-2
40.
25
16
.0045
A
DB
175,
50
51
:0043
A ,
D13-1
25
10
5.7
.0007
A
DB-2
75
25
25
.0046
A;
2-10
`l'ABLB 11*1,
continued
$erv� ce
Peak
PrQpogod
Channel
Area
Recurrence:
Ulnch4rae.
Channel
Channel
React
(Acres.
Inerrvtal
cCs
_ Syne
Sect idn
B
85
25 yr.
47
0.0013
A
BA
50
25
32
.0015
A
BB
25
10
14
.0065
A
F
215
50
76
.0037
A
FA
95
25
40
.0070
A
FB
20
10
7.9
.0073
A
G
75
25
35
.0002
p
GA
145
50
62
.0040
A
GA-1
25
10
10
.0052
A
GA-2
80
25
34
.0073
A
GA-3
50
25
25
.0083
A
GA-4
25
10
12
.0030
A
G`8
990
50
445
, 0010
H
GB-1
760
50
360
.0010
H
GB-�2
735
50
75
.0002
G
GB-3
450
50
200
.0055
GB-4
300
50
150
,0026
B
GB-5
25
10
10
.0002
A
GB-6
315
50
14$
.0020
B
GB-7
190
50
68
.0085
A
GD-8
80
25
45
.0030
A
GB-9_
70
25
24
.0055
A
Gla-10
90
25
37
.0080
A
- Drainage atruc;t ur a lmprovotnon t a
Drainage structures at road crossillys and levee outfall4t
irrequon,tly ,serve to Act as hydraulic c(introl s for drainage
channels, impairingtheir efficiency. Undersized. structures
{
are commonly responsible for road Washouts and/or backwat•'r-
ponding damages to upstream properties. Conversely, over-
sizing can prove to be a very-costly pr-acticC as drainage
structure: are typically expensive installations. According-
ly, drainage structures require a design that is :gully
cognizant of both the physical and the economical limitations
Of a particular installation.
This Plan features the maximum employment Of circular
Corrugated-metal pipe culverts,, and if limited by available
road grades, riveted corrugated-metal pipe arch culverts.
Low capital, cost and adequate serviceability were tho, main
E actors consideree ,.n this decision.
For planning and estimating purposes, all drzina:go struct-
ures were assumed to act exclusively as hydraulic-outlet
controls to the design discharge. This is a worst-case
assumption that can be verified, in part, by generalized
hydraulic-performance curves developed for topographical
gradients common to this area. 'Also tale relatively-long
culvert and conduit lengths, the employment O: tide gates
:Cor through-levee outfall conduits, and the variabje stages
of flow` in the flood-control channels utilized for some
outfall s, serve to reinforce the necessity of this outlet-
control 86sumption. 1lctual specific hydraulic requirements
along with some particular and/or specialized appurtenances
(wingwalls, headwalls,tide gates, cutoff wails, railings,
aprons, etc.) are necessarily deferred to final desiign.
-1
I
Spociol Xeaturotri of not,:, include: the rotolltion axed iml? OV
I �: a
Mont oC Structure No. I (the existing bridge on Highway 99'L,,)
which will require flOW-way lining and other orosion-control
or alignmont-traininc
,j improvements; StructtIro jjo. 10
I ( an
existing 36 -inch diameter corrugatod-metal 'pipe conduit
installed through the right bank levee of Mud Creek) which
io to be rotainodin. service in its present condition;
Structure No. 12 (an existing 42 -inch diameter corrugated -
metal pipe conduit in,�t4-;jlled through the right bank levee
Of Sycamore Creek) which in to be improved with the addition
of a single 36 -inch diameter pipe conduit, and Structure
No. 13 (an existing installation of triple 48"inch diameter
corrugated -metal pipe conduits installed through the right
bank levee of 8ycamore (..reek) which is to remain in service
with minor improvements. Structure, 14o. 7 (the existing
bridge on Keefer Slough at Garner Lane) is the only z;truct-
qre slated for complete. replacement. This was necw,-ritated
by a combination of the age, width, and grade of the bridge$
which will be incompatible with ultimate roadway require.-
equire-
menta.
Ponta.. All remaining drainage --structure imps ovementa ached-
ulod are non"cxiotcnt and require total construction.
Recommended draincage Structures are prosentod in Table 11-2.
TABLE 11-2
DRAIVAn STRUCTURE IMPRQVDfE-NT;
DRAINACE S'TRUCTM(S) REQUIRED
Structure
Design
Design
Discharge
'Type of
Required
Sleight
No:
Tregtiency
(ais)
Structure
Number
or
Diameter Stan
l
50 &
100 yr.
600/690
Existing Bridge
1 ea.
- 70' +
2
50
yr,
10
Wipe Arch
l ea.
16" 25''
3
50
yr.
5:4
Circular Pipe
l ea.
1$1'
4
50
yr.
5.$
Circular. Pipe
1. est.
1$"
5
50
yr,
34
Circular Pipe
2. ea.
24"
N
►� 6
50
yr.
63
Circular Pipe
3 ea.
30"
7
50 &
100 yr.
465/530
Circular Pipe,
4 ea.
60"
8
50
yr'.
57
Circular Pipe
3 ea
30"
9
25
yr.
31
Circular Pipe
2 ea,
20
10
25
yr.
51
Circular Pine
l ea.
36"
(>Jxis,ting)
(8xi.sting),
(Existing)
11
25
yr,
88
Circular Pipe
2 ea-.
48"
12
25
yr.
76
Circular Pine
1 ea.
4211 r
(Existing)
(Existing)
and
1 ea.
36" _
13
25
yr.
85
Circular Pipe
3 ea,
48"!
(tKisting)
(Existi n )
14
50
yr.
450
Circular. Pipe
5 ea,
54"
Project cont ntstimato 3
cost estimates attributable, two the construction o:C the
proposed storm-drO. nage fat il).ties were developed to asrist
in budget development and expenditure planning. Theso cost
projections; are ,intended to be representative, duly consid-
ering the almost -certain staging of facility cons truction,
and should be correct as to order-of-magnitur7e Accordingly,
while they represent realistic values, they should not be
construed as being absolute. R mid --1919 dollar basis was
utilized for those capital cost estimates and should be
modified, as appropriate, for future time frames.
These cost estimates aro presented, by particular facility,
in Table 11-3, and are expanded upon and summarized in
Table 11-4.
TABLE 11-3, CONSTRUCTION COST F,aT''friA'i�S
lIrovemOttt
I)escr:liUkt.,�..
1{si i maCecl
uoet„_.
Outfall, GhaklklCl
Acquire right-of-way, excavate
channel, provide~ leyea$, fencing;
and construct service road for
approximate length noted
Backwat=er Reach
µ 1,600 feet,
56,000
Transitional Reach
-, 11400 feet
33,400
Normal Flow Reach
- 5,000 feet
�8,9U0
SUBTOTAL,
$1:88,300
Collection MAnil:old
Acquire right-of-way, clear and
excavate, provide fencing, service
road and erosion -:control improvements
for bridge:
$' 114 600
SUBTOTAL;
$ 43,600
Keefer Slough
Lower Trunk:
Acquire right-of-way, clear,
realign and excavate 6,300 feet of
channel, provide r-encing and service
roads
(Channel Reaches B, BC, RR and ISG)
$ 81,400
Keefer Slough
Upper Trunk;
Acquire right -Of -Way, clear,.
realign and excavate 6)450 feet_- of
channel, provide fencing and service
q
roads
(Channel Reaches BIi, BII-1. ant] B1I-3)
$ S7 400
,.
.,
SUBTOTAL,.
$138, 800
j
2 :- 1, 6
�'AJ31.1;, �.�^.�, cOTlti,ll�letl
lm��rc�v m nt»
1)escrti.t�tfon
J.,-,t3tima.ta I
Cost
"A" Channel System:
Are excnvat o
8,350 fent of clia'nnt1., provide
fencing; nod service road,
(Channel Reaches A, AA AA -1,
AA -2 AB, and AJ3-1)
$125,300
p
111.3" Channel System;
Acquire right-of-way, excavate
29,1.00 feet of channel, provide
fencing; and service roads
(All 13 -Channel Reaches exceptik p
Keefer Slough Trunk peaches)
398,80Q
f
"C" Channel System.-.
Acquire right-of-way, excavate
9,900 feet of channel, provide_
fencing and service roads
('Channel Reaches C, CA, CA -1,
C13, and CB -1)
174,500
SUBTOTAL,.
$698,600
,r
"D" Channel System:
Acquire riglit;-of-way, excavate
14,000 feet of channel; provide
fencing and service roads
(Channel. Reaches D, DA, DA -1
DA -2, D13, Dia -1, and DB -2)
$225,,300
SUBTOTAL
$225, 300
"E" Channel System;
Acquire right-of-way, excavate
3,,800 feet of channel, and provide
fencing
(Channel Reaches g, BA, and M)C
$. +3, 700
SUBTOTAL:
$ 43,700
2-17
TABLE 11-3., contink►ad;
Improvement
)Estimated
�cjjp lon
Cost
it .rr ,�
1 Channel System:
Acquirevighr-of-way, excavate
`
7,350 feet of channal, provide
fencing and service roads
(Chatinal Reaches I`, VA, and, FB)$J.�_
,3JQ'
SUBTOTAL;
"C" Channel Syotem>
Acquire -right-of-way, ,^=a"vate
21,550 feet of channel, prcvi.do
fencing and service roads
(Channel Roaches G, CA Hirougli
CA -4, and OB through CB -10) .
$388,300
SUBTOTAL;
$388,300
;
2"18
TABLE 11-3, continued:
1mnr17ylllllC'n,�t
Drai.nava Structures,
Di.a�t�"r ,tyion
Uti.nmad
Cosi:
Structure
No.
1
Provide arosi,oa control and conveyance
improvements (previously included with
collection manifold)
N/A
Structure
No
2
install one 161' x 25" riveted C.M.
pi.pc arch with headwalls
1,800
Structure
No,
3
Instal.]. one 18" dia, C,M. pipe
culvert w3.tl4 headwalls
1,700
Structure
No.
It
Install one 18" dia. C.M. pipe
culvert with headwalls
1,700
Structure
No.
5
install 2 ea. , 24" dia. C.M. pipe
culverts with headwalls
2,900
Structure
No,
6
Install. 3 ca.,, 30" dia. C.M. pipe
culverts with headwalls
4,800
Structure
No.
7
Install 4 ea., 60" dia. C -M, pipe
cul.verts with headwalls and erosion-
control improvements, provide road
fill to grade
20,100
Structure
No.
8
Install 3 ea., 30" dia.. C.M. pipe
culverts with headwalls
5,100
Structure
No,
n
install 2 ea., 24" dia. C.1•t, ripe
culverts with headwalls
2,800
Structure
No.
10
l'tovido, minor improvements to existing
36" dia. C,.M. pipe conduit
5q0
Structure
No.
11
Install. 2 ca., 48" dia. C.M. pipe
conduits through levee, provide head-
walls, tidegates, and erosion -control
improvements
16,700
Structure
No.
12
Install 1 ed,; 36" dia, CiM. pipe
conduit through levee (in addition to
existing 42" dia, conduit), provide
Headwall, tidegate, and erosion -control
improvements
8,000
Structure
No.
13
provide minor improvements to existing
3 ea., 48" dia, C.M. pipe conduits
50
x.-19'
TA 31,* 11 3, ,continued
U tmuted
Improvement
Delo', boll
Cost
$tlrUctUl:0. N0. lu
Install 5 oa , $4" dia.
0,14. pt,pe
conduits through tovac,
pr'.,)Vide
lloadw lt,, j tidegacos, and
erosion-
control improvetilents
$ 41,400
SUIITUTAL:
$108,000
PROJECT TOTAL;
$1,944,900
2=20
0
Pro joct ql'toqing
The Cacilitico propo,,.3od witbin the Xrnmework o�C thin Plan
have boon phoned, according to priority of b0no;Citz
received and optimization of Zunds expended, into Raul
staging cnterjorion- Tho-roo
...Develop Outfnll Channc,, to IIOCIO C37001',
...Complete rinail 1)esign 8agincoring, of Plan DiLtrict
and define Right -Of -Way Requirements
Bt-itimotod ConptrUCtiOTI Cost 188j300
Contingency Fund 41,000
Engineering, Legal & Administration no'000
stage 1 Total 459,300
... Con.struct Collection ItInnifold
r)ovolop Lower Xoofer Slough Trunk
(Channel ROOK 1108 13# OC, Bt, & 8G)
Estimated Con8t5:uction Co ;t = 125.1000
Contingency Pund 271000
Engineering, LO(jal & lidminiootratioh = 19,300
Stage 2 Total 171 300
tag 0 -3
... conntruct O"tructuro No. 7
....Develop Upper Keefor Slough Trunk,
(Chonnel Roachea DII, DII-1, rx BIi-3)
to&timatod Construction Cost
77o500
Contingency Fund
21,000
Dnginccring, Legal & AdminIstration
11,500
Stage 3 Total =
$ 110,000
.,.Provide Remaining Drain8qO ImProvemolits
totimated Construction Co !,. ->t =
$11554' 100
Contingency Fund =
800,000
'Engineering, Legal & Administration =
206j000
stage 4 Total
2-22
In reconciliation o;C thi.t• proponed i acility- ,stc Vi,rng pr: og nqn,
the two i t OW Of �Sttujc I i4m o n.�r, dgned the ' .bighw4 — priority.
The corlotruC;'i ion of the outfall cbanl" cl will ali,mi.na to the
immeciiite problema of bac),cwnter Cloodj,xlg jlOq( IWaf $] cjj
,1114 ovortlOW f'loocli,ng Of 83tPtO Cli.cjhiflay 99E. Final c'lorign
ongineex inch Ind de,Cinition of right -of --wny r oqui omanttj for
�i
the entire dirtrict war, asnigneacl to thin, l); Vjj p for ity x:11
or+cic;" to nVOid i:uturc conflicts; os thi.,3 C, at)ertc-tj -),rea i
undergoing r, ipjcl ur:krani.zztion and nlo;.lt of the proposed chann-
al J,oentiona are not phyt xcally obvious. Might -of -way
idantificntion i.IoLllnl provide j vehi=cle 'to protacrt thous
loC Ation;; from fit Lure hind -u e conl1licty.
8tago 2 items, nr:c nearly ,the aame priority �.ave1 an Stage 1,
no dova'lopmortt of the collection manifold s?r,d the lol-jer
Dec or, ulough trunk will provide In immodiato bona -fit to the
name nt lnrgc- 6iwmililr;ly, theme i5 only a Millon dif'Zerancc
bctwcan Sta.10 2 r nd ul;trlge 3 phasing prior, itis ;, mr; the davel--
oFment 09 thO uI.laor.7 11,00for Slough trunk time, ,tj:jactur:c l;o 7
will ollovi c -to tome a)fi,t#i ing problom.� in •aha arson.
Btoge 4 r:oprenont ; a r: -alt tively-major oopntune jrj :Zio °ity
�rorri the fir;wt tllrior: ;qtr rbc;, in th�l: vhila tho.;o ;cili.tios
will Ovontunlly t"111 be r oquir acl, 'there i1c, cQrZollt:ly little
urganc,v Cor, th(,,ir pr.ovi-c ion. "imilt+rly, those it; only minor:
di-S,tinction ZO-C the imMoGi rcy of phat.i g any particular
group 09 im).-, ov0Mcntu within this Strga; hove;rex,, the oateb-
linhmont of outfall sti ucturas vend major inters eptor: , in
-rhe hj(jhcr -dG. nr;: .-ty or con,,tercial tires v wouic.�.or:;t�rZ a be the
bw;t ini'tic l pr; ogr c Itl.
-73
Pr0l!Min0,'7y iSn00s.,MCjj,t J)r0tjrpM
""'a .Corina Lion OZ 1,111 A4W,QC;.";MCnt Diotrict, a County' soxvico
4ren) or OtIlOr 109al entity Will 1,5robably be roquired to
Sarve vahic,*La, ;Car tlja
merl L*00-011 OT' a X:Ovonuc
PrOgraM to :Cvnd the davelopmelit O:C t1jo j.)roj,)O,,jf,
cl rtorr,,_
facilitiO8. Irrosljoctivo of.' the tyliv Of ontity
:COr111c(1, 0 d0tOrmination of jqj-jj,t J?ropQj,*tiw; Bono it, to Oint
wttent, and WIltit is nninc1J.vicluc11 parcel's
oquitaj)lo share
Of the project coit.t,s, -ill will eventually be required.
anticipation of thi4j cow se Of ovontn, concepto regard -
Ing an oqQitable cO."t di.stribution, pinc.1 o PrOliminary
48-130sment oproac.1 I,,-)vo
been aovajoj)ad to _01.
_VL
plann-
ing guide. 50mo of tilese conaiderationj, includo:
I - 'The drVil-ingO benofit;3 providecl sqit_j)in a zone
norvicad by ., particul jr. otlifall ll O
gone3L
loll
enhoncoi vil jancI8 of -the zone oil c 71ppro,,,_
imataly equal bnsir,. This prem illa r, ul.. p or to d
by bvt3ic-bonafjt considevations, VIC relative
constant y Of proposed land U,,,-Oo -
wid the
similar topogrvphy within, each pzarticular zone;
I
2. JAn equitaf,)lc Miathod of S WOUld be an
intra, -zonal -.1creago charge, ba8ed on the costs
Of iMprovoments: within each p,_tr t ic 1.11 cr zone;
3- An 4'ldJU�71tmcnt to thir, a0.-ja43:;mcnt method %vould
OP1.1y to landr iMmOdivtoly adjacent to the
natural alignment of 1eofer 4*loucjh, PC, the
rjrol?o,,-,ed improvertlent.-, will be OE nubrtantjA.
additional benefit to thwle lands (a, U. ; by
elinlillation of floocting, P. reduction in
developmental -,atback_e;, and on increased
achievability of p-roPOsed land-usa donvity)
Other a1.,pjica)jjL_ adjustments
incluele distance z , could potentially
On,0S from the ProLjored
aervice chnnnolo, vm& adjustment :, for tolo-
qrap,hicajly high arear; with -1claqw.ito natur,11
drPinngo.
I it typical C-MV19 Of an intro-torinl, vCroage charge - c__
mont '91"'rood for :rj.va difXeront zonasa a,ithin the boundprios
of the I-roposed district, is
i,<; as :sol] OW11:
2-24
�jono 2 is conprisod of t110 340 -acre aren SOrviccd by all
"DII-r,rcfixed cjj,-.nrjclC,. pr opored jMj)rovO
M 0 11 t;,-
� comet of
tllcsG channel„ and ninurtonant drain.ago Etructuros, esti-
mated to coat OPPrOXininttly $355,000. Thir xotu],t, in a
,;Orvo(I I)y
and aon.,:J.0t of those
channel , the outf,-113. channel, the colt eci;ion manifold,
and appurtenvmt dr,*jin,,.Icjo St�rtCtUrcN_ The total coot of
thotm improvommitr, J.�G 0,$tim(nted It $3,1587,400 an(
, I . I is to I)e
dittributed to a 1,640 -acro "'Orvica )r0a. 4x(J-dition,)jjy,
londs Within 300 feet or, tho natural gaEkj.,or r, jouglj'align_
r,lent are to aW,"Sumc, n$ all eXamplo, 251,','> of the coots of the
in -proved XcoC-cr Slough trunk, the collection ME,
,nifold, ant,
the outf-all channel, duo to aPccial )DO110fit5 realized.
0
This, rC&3ults in an OvOrallpor-acro charge of $887 for the
aren in general, and an ndditionnl por-acro charge oZ
$763 :COI: the I-Onds immodia,tOly-adjacont to E,00:COr Slough,
for a total of $1,650 per acre in this 300 -Coot special
benefit area.
�jono 2 is conprisod of t110 340 -acre aren SOrviccd by all
"DII-r,rcfixed cjj,-.nrjclC,. pr opored jMj)rovO
M 0 11 t;,-
� comet of
tllcsG channel„ and ninurtonant drain.ago Etructuros, esti-
mated to coat OPPrOXininttly $355,000. Thir xotu],t, in a
Per -acre chaj,ge of $1,047 for the sorvice area.
one 3 is Compziciod of 'GlIc area served by I'L111-prefixod
cl'I411110 a. Tinprovomontr, pzopo,od for thi-S, 80 -acre area are
c:atimatad, to cost $670700, resulting in a per -acre charge
of about $847.
;'lone 4 consi,Ls of the 210 -acre area ,,,,ervicod by the
faciliticL of the 'T "-Prof ixed channels. IMprovorjents are
Ostim",ted to tort $170,300, resulting in a per- charge
Tier -acre
of $Cll.
'60nc 5, includc,', the arcC+,r; -,Orved by the X-acjAities of the
iind chnnnel.,,. jille Os0 improvemontare
to, co.,,t $6,19,500 r__Ind ir') to be distributed to a
590"pere service zirco, Eor P per-zcre charge of $11050.
2-25
rx41'�tk,a,ra oto alit l 111 in too cont i a .ltc.cl t a t i, a, i qht
acroago Sero d, with 'All Zono" combined, which coin
amount: to about $980 per acre.
' hoso costs and ar;;;oa menta would nocd to be i,ncrearcd by
n Pastor of about 2dra if c � t'RG' � �IriCI;1'L"-ctic t,ri�t �ixi�+riCi ng
lrr, occc1urati were omployecl. Thit inc:r a,a le would ba necoao -
-Iry to occou',11t for a_ddationoi legal fee , a ��essmont
engineering, agency in*pect:i.on, bond disc-
ount, and for other incidental extjen:,e l incurred ill diLt ict
;Corm tion. 1f such fUnancing procedures were employed, 1roa a
of the cited zones would an ume a bonded indebtednoa
ranging from �ipp.ro,cima,tely $973 per acre to $3.,980 per scre.
'If heac, if amortized over a 15-y o ir. f,.er iod at, a 10;' inter ost
rite, j`oiilci amount; 'to annual payments :railgillri from $128 to
$260 per Acre, rest,,ectively.
The cootk; roquarod to provide storm-d.a: aintge f;,ci.li i:ieo for
thio district ore Substantial, which i. in p,-rt due to
Several factors: the influence of rola-dj.;;Lrict upat,ream
tributary the absence of a,dcauate drainage out:Calln
.runoff-
tho physiographic qc, ometry or the ore, and resulting low
gradients; conflict-, with existing 7wulalic--works iml., -ovemontrp
(highway: roach, levees, etc.) W- t.a�.l VA With 0 d,`I)ting
,
xeoidantial clevclopfactrtc; and the ,71-jundan.ce of iloli-a�oe4�sblc°
areas (e ri. i the abnncionad c„and & gravel quarry, f l.00d-
convcyr nae arca$, jjor'tiora ;' a1 the City o� Chico air ort,
c lrport cloalr qne, endl the lands, of the proposed airport
illdut�•tzi.,al par)',, and tomo contaguour, agrieultul-al lands).
pid, there �,q little curtent oppoxtunity for
X11 this re'-
roclucitIq tho cof is oE this p o joct. Howover, r n opportunity
for p, rt±:i.ally, r Ileviatingj the fintiZcialbutdon exist i± the
t;axi,lsut.nry 14 1tc: , oi: the nirpoa: t complwx were incorporates
2-2G
..into the dar--gait- TbJ..,,4 nction could bstarvc to iR,s.cr4Nfi'tm the
P4Isesrmont, be io by about 500 acre; , witril tile adcli tion ox
only rolitively-manor dra noge improvemwits Co currenco r
the City OR Chico_ would, be required to include there e,roo:;
in piny tyi',o of arr di,,trict
Simi.l tirly, if the .;end & c1rovel qu rry were subjected to zr,
recIvm-ition program, it could be i.ncludod in the tsvo sment>
boon (50 ocrao +) , whet ea;s only manor levies, could be
Curr rdntl.y nc,. es: ad to it. li; the agricu:l.tu,ral lsnds to the
t
tire: , and Pertriculcrly those lando Kctj cei t to the out�Z,ll
channel, wore to be r: ezoncd for trntur: e re! %idential develop-
evelop-menl-
ment(a very-doubtful occurrence), they could also par: tic-
i.patrc in the ns.,,ora yment: bose. only very-minor l ovie.� could
be equitobly soot�c8L4ed to Axone londri they e.ci nt in
3
the current 4 griculturnl :Land-use s atu 8 .
2-2T
� � YM1 Y 4 ' 1 i `�, q
t� ..! .'�i �.� 1� 1.,.1 F 4 � ti'�". t �, a i. f � �"1� � ,� } 7 1 SOI .�� t.. 7 9+� �+ 'y,c4�)a ... ' r A. .s t v I
t a 't t c' � i ;. v+ ` ; t4 1 i � � � c kl� t k ) � � � ,+ S � y
n� i a ., 11 .. + I 6 � i♦ a r t i ,+4
11,1. 1 4 C �} t� a � f a «� t 4 f I '� A ��� /�-rt it f 4 � t- � 'jj� ��//
f 4 t � K 1,, F.�Yry j, y y^� 1 /� , 1 { � ( C'�k, � t., �� vlr+ � t.: �� �' i 1'YP Y !�✓�ir 'd k � 1 �,t �i1iM �� � � � � � i, -i+Y.�
_ �._.� _.. a, i1' i '3.. �:. _ ��wi� ...11J.�°�i pit _ _ �?�. i �•i �u.'t1 A .. .1.,�.. � e '. "�1. b .x ate.;J• ,s+k �J
��° .
�'Y�
r
MASTER STORM-DRAXNAGi FLAN
for the
UPPER MUD CREEK AREA
and the
MERIDIAN--MUNJ'AR AREA
of
Butte County, California
prepared for the
BUTTE COUNTY DEPARTMENT OF PUALIC WORKS
Clay Castleberry, Director
A
by
JON M. ANbtA80N
Consulting Civil Engineer
Chico, California
November 1979
`!'11,8I:,8 OF CONTENTS
Pat c No.
PART x: :Design & Planning Considerations ..» ..
1_1
INTRODUCTION ......•.••••♦♦.Y•• •♦•.,.».»
�.»�
Location ... . . • • . . . .. • • . • •.. • . . Y . • _ .. . . « •.
1.'. 1
Purpose Scope ......................
1-2
Description 0f the Area ............
1-4
Budgetary Limitations
1-6
...........
CLIMATOLOGY ...........................
1a-7
General ........... .. ........ ....
1-7
Precipitation .............
1-7
Hydrological Ramifications
1-8
..........
DESIGN CRITERIA .... ..4 ...........
1_1.0
...
HYDROLOGIC .ANALYSIS ...................
1-12
General .... .... , . . ... ..
1-12
Hydrologic methods .........
1-13
Empirical Models ............ .. .....
1-14
REFERENCES .. . ,, . ... » ...................
1-1.8
PPAART_II: Lipper Mud Creek Master Plan
2-1
Y ... • ....
INTRODUCTION .... .. . .. .... ....
2-1
CONCEPTUAL CONSIDERATIONS
2-2
...............
TECHNICAL FEATURES • .....................
2--3
Typical Channel Sections ..........♦..
2--3
Keefer Slough Design Discharges ......
2-3
Outfall Channel. .... • ............ ♦ ...
2-5
C01.l.ection Manifold .. ......
2-7
Drainage Channel System .............
2-9
Drainage Structures ......... ....•...
2-12
Project Cost Estimates ........,•.
2-1.5
Project Staging ....,.,.»....
2-22
........
Preliminary Assessment Program ...0...
2-24
PART -Illi Meridian-Munjar Master Plan ............
3-1
INTRODUCTION . ;......... ...... . . : :`....
3-1
CONCEPTUAL CONSIDERATION'S ...............;
3-2
TECHNICAL FEATURES . ..... , ..
3-4
Diversion Channels ..........
3-W4
........
Improved Natural Channels ........:...
3-6
Channel: Construction & Realignment :. ,
�-8
Drainage Sta:uctures ...............«:
3-9
Drainage Outfalls ....................
3-I'2
Project,Cost Estimate's :...'
3-15
.. ... ...
Project Staging .........`.•.•......
3-21
Preliminary Assessment Program .....
3-23
I
TABLE OF CONTENTS ( cot) tinuod )
Page No.
TABLES:
Storm --Drainage Deaign Criteria ..
1-11
x1-1
Design Channel Improvements .,..„,.
21-10
11_2
Drainage Structures ..... .. , 1 1 1 1 ..
2-14
11-3
Construction Cost Estimates .....
2-16
12-4
Project Cost Summary ......... ..
2-21
111--1
Diversion Channon. Improvements .
3-5
111-2
Natural Channel Improvements .....
0
3-7
111-3
Drainage Structures ..............
3-11
111-4
Construction Cost Estimates ......
3=16
111-5
Project Coat Summary . ..... .....
3-20
PLATES:
Upper Mud Creek. Plan Map .........
In Pocket
Meridian-Mun,jar Plan Map .........
in Pocket
FIGURES
1-1
Location Map
i
1-2
'Precipitation Intensity-Duration-
ntensity.--Dur.ation-Frequency
Frequency.. .. _ .. .
1-9
II --1
Typical Channel, Sections ...1111..
2-4
11-2
Collection Manifoic ....... s ...
2=.8
CONCEPTUAL CONSIDERATIONS
This area involves large expanses Of marginal -value acreage,
relatively -large parcel sizes (5 to 10 acres typically), and
a Very -limited tax base. These factors combine to produce a
set of unusual engineering and financial constraints for
the development of storm -drainage facilities. The negative
aspects of those constraints are partially countered by the
geoqs�aPhical advantage inherent in being completely surround-
ed by range and agricultural lands of limited productivity
and value. This situation allows some latitude for the
employment of engineeging inovation and for economic trade-
offs.
An examination of the Meridian-munjar area topography will
indicate that drainage is typical of that attributable to
the apex -area of an alluvial fan, in that!
2. Drainage patterns are generally radial and subject
to temporal changes in response to continual fan
erosional./depositional- processes,
2. Manyofthe 0% sting natural channels and swales
are larger than expected and must have been devel-
oped by erosional regimes coinciding with a stream
Or streams having much larger discharges (and
drainage areas) than the ephemeral streams, current-
ly
present (,this stream Was most certainly ancient
Pine Creek in transition, which again in the
near
geological future could reclaim these braided and
sinuous channels).
in addition, further examination of the topography suggests
that much of the runoff that causes drainage proble_q8 in
the Mer"Ldiah-'Munjar district area is probably attributable
to Overland flow originating from aPproximatoly two square
miles of upstream tributary drainage area (note tributary
drainage divide on Plan map). Inrecognition of this, it is
surmised that if the large volume of overland flow originat-
ing from the upstream -tributary drainage area , could be
intercepted and diverted around the district I r t boundaries the
-2
�1
existing natural channels would probably suffice: for
storm -drainage purposes. More importantly,, this coul4
probably be accomplished at minimal cost.
Subsequent calculations. proved th3,8 diversion concept to
be true and feasible, if
1.. The existing natural channels were provided with
minor improvements, realignments, modification,
and maintenance;
2. Limited channel construction and embankment were
to be provided;
3. Drainage easements for a tormwater diversions
could be obtained,
4.- The efficiency of hydraulic structures could be
improved and enhanced; and
5. The channel of Pine Creek could be assumed to
remain in its present location, via either
natural or artificial processes, and that over-
flow would not be a major oonsideration in the
district (this is more appropriately a flood -
control problem than a storm -drainage parameter).
it would be presumptuous to assume that the natural channels
and swales within the proposed district- boundaries would
remain useful and unchanged by human activities. In recogn-
ition of this potential problem, major natural channels
have been identified for protection, improvement, and maint-
enance, ,all of which will require a legal vehicle for
implementation (1.e. via, acquisition in fee title, by ease-
ment, or by ordinance).
The location of the proposed diversions, natural channels
y
to be imDroved. channel conz;t.runt i nti ri1l7rin nl iAloni ; rir,n,n„f-m
TBCHNjCLL_r.L'ATUAL's Op TIITa ULAN
-Diversion Channels
Two drainage diversions serv(u. as the primary functional
features Of this drainage plan. These diver'sions have
0 been 'planned as wide, shallow channels that are to be
developed cIlMOPt exclusively As excavation sections. The
excavated L spoil may then be utilized for berm construction
C
on the jowngradient side of the channels, serving a dual
0 purpose as freeboard and as an access road.
Wide, shallow, trapezoidal channels are Proposed for
the diversions in order to minimize erosion potential,
improve ,safety, and to assist in maintainability. In
Addition, this configuration will Maximize their compa't-
ibility with the seasonal -range land use Of the contiguous
area.
Foncinq for security and safety purposes will not be 4
general requirement due to the relative isolation of the.
diversion channels. . SPOcific exceptions include the area,
9) Immediately adjadent to Munjar Road, to Meridian Road, and
along the southerly side of the west diversion channel
westerly of Meridian Road. Additional fencing maybe
required, in isolated situations, as development of
the
area progresses. A minimum of three"strand barbed wire
fencing should be adequate for all applications.
Provisions for erosion control and energy dissipation
'Will be -required it the, terminus of those diversion,
channels'(riprap,,stilling basins, aprons : I These
etc.).
-ire not anticipated to be major items.
Recommended channel configuration$ are presented in,
Table 1II-1.
3-4
TAIL 111-1
Daul;a�sa~aav ��cnrra�a�r;
:�>vu�t�o�raari�tv�rs
-Emit
Diversion
Channel
a)es:►
n Channel:
Properties
Tributary
Design
Design
Depth
Drainage
Recurrence
Discharge
Channel
Base
of
Average
Reach
Area
Interyal
c. f, s.,�
SloneWic't,h
Flow
Velocity
a
655 acres
25 yr.
240
0.0053
30 ft.
1.6 ft.
4.6 E.p,s,
b
415
25 yr.
190
MOO
22
1.7
4..4
c
375
25 yr.
150
0.0023
22
1.9
3.2
d
240
25 yr.
97
0,0023
15
1.8
3.0
e
70
25 yr.
30
0.0074
8
M
315
=West Diversion
Channel
Design
Channel
Properties
Tributary
Design.
Design
Depth
Drainage
Recurrence
Discharge
Channel
Base
of
Average
Reach.
Area
Interval
c s.
Slope
Width
clow Velocity
s
220 acres
25 yr,
96
0.0054
10 it.
1.7 Pt.
4.3 f.p. ,
b
95 acres
25 yr.;
60
0.0043
8 Et.
1.6 ft,
3.1
3:
- Improved Natural Channels
dp
I(ey natural channels have, been selected :Cor improvement,
These channels were located to provide an adequate access-
ibility and drainage density throughout the district (the
need for whir.,; incroasea with increased distance downstream
,jo diversions). In goneral, and
from the proposed drain,)c
wherever possible, the largest or most hydraulically compet-
ent of the existing natural channels were selected.
Channel improvements are expected to consist of relatively
limited excavation,, dressing, clearing and realignment.
These Improvements will be required, as necessary, in order
to concur with the specified channel design properties, and
with the locations shown on the Plan map. Fencing will not
be a general requirement, since these will be natural chan-
nels that convey reduced flow quantities in a very -low
density residential area. A minimum of 3 -strand barbed wire
fencing may eventually be required along the reaches of
channels "All and "M11 that are to be adjacent to residential
areas, as the;ie channels will be artificially conveying
additional runoff. Access points and rights -of -entry for
maintenance purposes should be acquired in coordination
with the progression of future residential expansion and
development patterns.
Aecommended design channel properties are presented in
Table 111-2.
3"16
TABLK
11:1;-,2
NAT.UJOL CHANNEL
lMVHOVI0lJZTS
Design Channel, 'Properties
Minimum
Maxlmwn
Channel
Service
1)� Rign
Flow
Flew
Average
and
Area
Channal.
Recurrence
Di,ocharge
Area
Depth
Velocity
Jtca.ch
(Aeres)
Slope
Interval(c,1.s.
)
z
f xt)
_44
(feet) eatj
(Ct /sac).
A
565
0.00/15
25 yr.
190
_
2,6
4.5
Aa
505
.0045
P5
180
42
2;5
4-li
Ab
285
.0074
25
130
28
1.9
4.9
8
60
.0050
10 yr,
22
8
1.5
2.7
C
285
.0040
25 yr.
100
28
2,1
3.7
C-1
25
.0048'
10
12
8
1.5
2,4
C-2
30
.0055
10
12
8
1.5
2.4
C-3
90
.0052
10
30
1.1
1.5
3.0
C-3a
55
.0071
10
23
81.5
3.2
C-4
120
.0060
25
51
15
1.5
3.5
D
80
.0024
10 yr.
25
12
1.5
2.2
C
120
.0051.
25 yr.
47
1.5
1.5
3.2
Ca
25
.0035
10
11
8
1.5
2.0
F
210
,0049
25 yr.
77
21
1.8
3.7'
Fa
160
.0072
25
70
18
1..6
4.2
>b
55
.0079
10
24
8
1.5
3.4
0
55
.0055
10 yr.
19
8
1.5
2.7
11
75
.0056
1.0 yr.
24
8
1.5
2.8
Ha
50
.0070
10
20
8
1.5
3.0
1
140
.0061.
25 yr;
57
16
1.5
3;7
J'a
90
.0073
10
53 _
10
1.5
3.3
Jb
50
.0087
10
22
8
1.51
3.2
K
115
:0077
25 yr.:
J
13
1.5
3.9
Ka
50
.0086
10
23
8
1.5
3.3
L
145
.0069
25 yr.
71
20
1.6
3.6
L-1--
To be constructed/See
.later section ---
L-2
95
.0097
10
37
10
1.5
3.7
i
L-24
60
.0078
10
27
$
1.5'
3.4
L-2b
25
.0120 '
10
14
8
1.5
3.3
I1
1200
.0086
25 yr.
360
65
1.6
5.6,
3�
-channel ConcitruCtion and Roalignmont
Although the philosophy of this master Plan hay centered.
about maximizing the use of natural channels, two minor
channels will need to be constructed.
Channel L-1 will require construction to provide adequate
drainage density for a service area that is almost complet-
ely devoid of well-developed natural channels (with the
proper alignment)4 The recommended configuration for
Channel L-1 is:
Design Service Area = 50 acres
Recurrence Interval = 10 years
Design Discharge 21 cfs
Channel Slope = 0.0077
Base Width 3 feet (2:1 trapezoidal channel)
Depth = 3.2 feet (including freeboard)
Average Velocj,Ly = 3.7.ft/sec
Fencing will eventually be required (3-strond, birbed wire
minimum) since this is not a natural channel. However,
this can be, phased with development of the area, as it is
currently quite isolated.
Channel C Will require partial construction for realignment
to Culvert CT -14 on State Highway 59D. This realignment
was necessitated in order to preserve the capacity of
culvert CT -15, which is slated for use with an equalizing
channel'(see later section). It will also, -utilize the
nvnes-mm I'ViPH r =I 0, i r, rmnne- i. i -v nO e711 1 17cirt- rT_ 14 1*1
Desivn 5Qrvioe Area = 285 r cran
Recurrence Interval = 25 years
Design Discharge = 100 cf s
Channel ,Slope 0.0026
r
Base Width 8 feet (2:1 trapezoidal)
Depth (including freeboard) = 4.1 Loet
Average Velocity c 4.1 f_Vsec
Due to the relative isolation of this area, fencing will
not be required unless future developmental patterns en-
croach on the channel.
--Drainage structure improvement
Drainage structures at road crossings frequentl act as
hydraulic controls for drainage channels. Additionally,
undersized structuresare commonly responsible for load,
washouts and ponding damage to upstream properties. How-
ever, drainage structures can be very expensive and over -
siting is usually a costly practice. Accordingly, drainage
structures require a design that fully accounts for the
physical .and economical limitations of the particular
installation
This plan advances the maximum employment of circular
(corrugated metal) pipe culverts or riveted pipe arch
(corrugated metal) culverts when limited by feasible or
available road grades. I,aw capital cost and adequate
serviceability were the main factors in their selection.
�g
For estimating purposes; all structures wore assumed to
serve as'.hydraulic inlet controls. This assumption has
been verified by generalized hydraulic -performance curves
and is reasonable for topographical gradients common to
this area.. Accordingly, specific hydraulic requirements
3-9
for outlet-oonttol qonditionso alonq with :Ione particular
appurtonanca:i (npecialized headwalls, wngwalls, railings,
aprons, etc.), are necessarily deferred to the recommen-
dations of final design.
Particular special features include the planned removal
and replacement of, drainage structures No. I and Igo. 2
(currently reinforced -concrete box culverts). This was
necessitated by a combination of- both their age and con-
dition, as well as their incompatibility with proper r.)ad-
way widths and grades. in addition, Structure No. 1 should
be relocated about 130 feet to the south of its present
location. Thio, along with a minor channel realignment
and a realignment of Rock Creek Road, will greatly im-
prove the hydraulic efficiency of the drainage structure.
Structure No. 2 is currently located in a rather abrupt
road dip, which, whon corrected, will allow the use of a
large diameter pipe culvert.
one particular option of note would be the potential
substitution of a timber or flatcar, bridge at Structure
00, 10 Munjar Road crossing at East Diverts,ion Channel).
This alternative may be economically viable due to the
very low traffic volumes expected and the shallow flow
conditions anticipated.
A major e,"Iccption to this section is that all culverts
on Highway 99B are to remain in service as -is, with the
proviso that they receive minor improvements and main-
tenanco (see later section).
Recommended drainage structure, improvements -are presented
in Table '111-3.
3-10
Design DRAINAGE STRUCTURE (S): REQUIRED
Service Design Design,
Structure Area.Recurrence Dscharbe Height
chs Structure
of Required or
No.
(Acres) Interval ( ) Number Diameter S
0
past
l
1,920
25 yr.
420
Pipe Arch
7
ea.
36'`
,$`r
2
130
25 yr.
53
Circular Pipe
I
ea.
42"_
3
50
25 yr.
26
Circular Pipe
2
ea.
24 ,x
s
w 4
-�
160
25 yr_
71
Circular Pipe
3
ea_
30"
_
S
95
25 yr.
45
Circular Pipe
2
ea.
3011
6
110
25 yr,.,
51
Pipe Arch
2
ea.
27"
-43`T
7
50
10 Yr.
22
Pipe Arch
P
l
ea.
22"
-
36"
8
50
10 yr..
23
Pipe Arch
I
ea-.
22"
36''+.
9
25
10 yr-
14
Circular Pipe
1
ea.
24T
_
10
64G
25 yr..
230
Circular Pipe
Zea,
36'=
{
l
Storm drainage from 'the project area will dr-oin (as it has
historically) via overland flow in natural channols to the
culverts on State Highway 991x, and ultimately to Vine Creek
(after traversing four 'to five miles of agricultural, lands).
These Highway 99H culverts Presented a potential physical
and economical probleva as most were designed and constructed
prior to the existence of good topographical mapping for the
area (probably between 1930 and 1945). Consequently, mjny of
these culverts were underdesigned, causing grequent poriding
along the east side of the highway during periods of heavy
storm runoff. This situation has been improved, in Part, by
the recent retrofitting of some complimentary pipe arches,
but the combined facilities still remain only marginal.
An initial objective in the preparation of this Plan was to
observe a basic maxim that the capacity of there Highway
99E culverts should not undergo major expansion, insofar as
Possible, since the anticipated costs could have severe,
consequences on the financial viability of the total proj-
ect. As an alternative, a Channel realignment, an equaliz-
ing channel, and drainage easements are planned as vehicles
to minimize -these culvert -capacity limitations.
The respective drainage, areas tributary to each Highway 99E
culvert for existing and propos5ed. conditions (prior to an
equalizing channel) are as follows.,