HomeMy WebLinkAboutCT 13-03; ROBERTSON RANCH-RANCHO COSTERA; HYDROMODIFICATION SCREENING FOR RANCHO COSTERA AND EL CAMINO REAL WIDENING; 2013-06-19HYDROMODIFICATION SCREENING
FOR
RANCHO COSTERA
(ROBERTSON RANCH PLANNING AREAS 1-11, 139 & 23A-C)
EL CAMINO REAL WIDENING
June 19, 2013
Wayne W. Chang, MS, PE 46548
changmmmDmm
Civil Engineering o Hydrology. Hydraulics o Sedimentalion
P.O. Box 9496
Rancho Santa Fe, CA 92067
(858) 692-0760
CT i!-°'
-TABLE OF CONTENTS -
Introduction................................................................................................................................... 1
Domainof Analysis......................................................................................................................3
InitialDesktop Analysis................................................................................................................6
FieldScreening .............................................................................................................................7
Conclusion..................................................................................................................................12
Figures.........................................................................................................................................13
APPENDICES
SCCWRP Initial Desktop Analysis
SCCWRP Field Screening Data
MAP POCKET
Study Area Exhibit
Rancho Costera Drainage Study - Proposed Condition Work Map
Per the first bullet item, the first permanent grade control point was located below POC L and
POC P through a site investigation and review of aerial photographs. The waterbodies below
POC L are Agua Hedionda Creek, Agua Hedionda Lagoon, and the Pacific Ocean. There are no
permanent grade controls within these waterbodies below POL L, so this first criteria does not
apply for POC L.
For POC P, the natural receiving watercourse continues for over 1,000 feet, where it becomes the
concrete-lined Kelly Drive trapezoidal channel. The Kelly Drive channel was recently repaired
by the City of Carlsbad. Chang Consultants was under contract with Clayton Dobbs and Sherri
Howard at the City and assisted in obtaining the resource agency permits for the repairs. Since
the channel is concrete and a primary public drainage facility, it is considered a permanent grade
control. Therefore, the upper end of the Kelly Drive channel is the first permanent grade control
below POC P.
The second bullet item is the tidal backwater or lentic (standing or still water such as ponds,
pools, marshes, lakes, etc.) waterbody location. The nearest significant tidal backwater or lentic
waterbody is for POC L and P is Agua Hedionda Lagoon. From Google Earth, the upstream
extent of the lagoon is over 4,500 feet downstream of POC P. For POC L, the lagoon is
downstream of the Kelly Drive channel permanent grade control, so the lagoon will not govern
for establishing the downstream domain of analysis location.
The final two bullet items are based on 50 and 100 percent tributary drainage areas (in this case,
the channels are in urban areas, so the 100 percent criteria will be used). The natural channel
below POC L confluences with Agua Hedionda Creek approximately 220 feet below POC L.
The overall area tributary to POC L covers approximately 5.11 square miles according to a 2008
Letter of Map Revision Request for Robertson's Ranch by Chang Consultants. In comparison,
FEMA's May 16, 2012, Flood Insurance Study indicates that the Agua Hedionda Creek
watershed covers 23.8 square miles at El Camino Real (see Appendix A for excerpts from both
reports). This information shows that the Aqua Hedionda Creek tributary drainage area is much
greater than 100 percent of the POC L drainage area. In addition, for POC P, a 100 percent larger
drainage area occurs where the Kelly Drive channel confluences with Agua Hedionda Creek.
Therefore, for both POCs the tributary area criteria is met where their downstream channels
confluence with Agua Hedionda Creek.
Based on the above information, the downstream domain of analysis below POC L occurs at the
confluence with Agua Hedionda Creek, which is approximately 220 feet downstream of POC L.
There is no permanent grade control associated with POC L and the tidal backwater is several
thousand feet further downstream of the confluence.
The downstream domain of analysis for the natural channel tributary to POC P is at the
permanent grade control created at the upper end of the Kelly Drive concrete-lined channel. The
tidal backwater and 100 percent tributary area are further downstream of the Kelly Drive
channel. Per the first bullet item, the downstream domain of analysis is one reach below the
grade control point. As outlined above, a reach is not to exceed 200 meters (656 feet). The
concrete-lined channel is longer than 656 feet, so the reach will be within the non-erodible
4
Reach I Tributary Area, sq. ml. Valley Slope, rn/rn FValley Width, m
El 0.2400 1 0.0289 6.1
F-E-21 0.0731 0.0551 1.5
_E31 0.0732 0.0369 - 1 1.5
E4 0.1272 0.0247 8.5
F-E-51 0.3963 0.0092 F-1 1 .6
_E61 0.3964 0.0088 4.6
_E71 4.6800 0.0060 16.8
F_E8__j 5.1100 0.0091 F 25.9
Wi 1 0.0054 0.0448 2.4
F _W21 0.8078 0.0191 6.1
W3 1.1157 0.0127 I 17.7
W4 1.2688 1 0.0183 I 4.9
Table 1. Summary of Valley Slope and Valley Width
FIELD SCREENING
After the initial desktop analysis is complete, a field assessment must be performed. The field
assessment is used to establish a natural channel's vertical and lateral susceptibility to erosion.
SCCWRP states that although they are admittedly linked, vertical and lateral susceptibility are
assessed separately for several reasons. First, vertical and lateral responses are primarily
controlled by different types of resistance, which, when assessed separately, may improve ease
of use and lead to increased repeatability compared to an integrated, cross-dimensional
assessment. Second, the mechanistic differences between vertical and lateral responses point to
different modeling tools and potentially different management strategies. Having separate
screening ratings may better direct users and managers to the most appropriate tools for
subsequent analyses.
The field screening tool uses combinations of decision trees and checklists. Decision trees are
typically used when a question can be answered fairly definitively and/or quantitatively (e.g., d50
< 16 mm). Checklists are used where answers are relatively qualitative (e.g., the condition of a
grade control). Low, medium, high, and very high ratings are applied separately to the vertical
and lateral analyses. When the vertical and lateral analyses return divergent values, the most
conservative value shall be selected as the flow threshold for the hydromodification analyses.
Visual observation reveals that most of the study reaches contain a moderate to densely
vegetated channel (see the figures following the report text). The vegetative density extends
relatively uniformly across the channel bottom and sides. Due to the vegetative cover, riprap
energy dissipaters at each POC, and lack of significant erosion noted during the site
investigation, the vertical and lateral stability was anticipated to have a limited susceptibility to
erosion.
7
Vertical Stability
The purpose of the vertical stability decision tree (Figure 6-4 in the County of San Diego HMP)
is to assess the state of the channel bed with a particular focus on the risk of incision (i.e., down
cutting). The decision tree is included in Figure 30. The first step is to assess the channel bed
resistance. There are three categories defined as follows:
Labile Bed - sand-dominated bed, little resistant substrate.
Transitional/Intermediate Bed - bed typically characterized by gravel/small cobble,
Intermediate level of resistance of the substrate and uncertain potential for armoring.
Threshold Bed (Coarse/Armored Bed) - armored with large cobbles or larger bed
material or highly-resistant bed substrate (i.e., bedrock).
Channel bed resistance is a function of the bed material and vegetation. The figures after this
report text contain photographs of the natural channels in each study reach. A site investigation
and the figures indicate that the vegetative cover throughout each natural channel within Reaches
El through E4, E8, and Wi through W4 is mature, dense, and fairly uniform (see Figures 1
through 10 and 17 through 26). The vegetation in some areas is so dense that the channel was
either difficult to access or not possible to access at all unless the vegetation is trimmed. The
vegetation consists of a variety of mature grasses, reeds, shrubs, and trees. Vegetation prevents
bed incision because its root structure binds soil and because the aboveground vegetative growth
reduces flow velocities. Table 5-13 from the County of San Diego's Drainage Design Manual
outlines maximum permissible velocities for various channel linings (see Table 5-13 in
Appendix B). Maximum permissible velocity is defined in the manual as the velocity below
which a channel section will remain stable, i.e., not erode. Table 5-13 indicates that a fully-lined
channel with unreinforced vegetation has a maximum permissible velocity of 5 feet per second
(fps). Due to the dense cover and mature vegetation, the permissible velocity when erosion can
initiate is likely greater than 5 fps in most of the natural channel areas. Table 5-13 indicates that
5 fps is equivalent to an unvegetated channel containing cobbles (grain size from 64 to 256 mm)
and shingles (rounded cobbles). In comparison, coarse gravel (19 to 75 mm) has a maximum
permissible velocity of 4 fps. Based on this information, the uniformly vegetated natural canyons
in Reaches El through E4, E8, and WI through W4 has an equivalent grain size of at least 64
mm, which is comparable to a transitional/intermediate bed.
Figures 11 through 16 show that Reaches ES through El contain sparser vegetation than the
other reaches. Therefore, a relationship between vegetative cover and grain size is not applicable,
and pebble count must be performed. Figures 15 through 17 contain photographs of the typical
bed material within these three study reaches. A gravelometer is included in the photographs for
reference. Each square on the gravelometer indicates grain size in millimeters (the squares range
from 2 mm to 180 mm). A pebble count was performed (see results in Appendix A) that
determined the median (d50) bed material size to be 11 millimeters (mm) in Reaches ES, E6, and
El.
8
In addition to the material size, there are several factors that establish the erodibility of a channel
such as the flow rate (i.e., size of the tributary area), grade controls, channel slope, vegetative
cover, channel planform, etc. The Introduction of the SCCWRP Hydromodflcation Screening
Tools: Field Manual identifies several of these factors. When multiple factors influence
erodibility, it is appropriate to perform the more detailed SCCWRP analysis, which is to analyze
a channel according to SCCWRP's transitional/intermediate bed procedure. This requires the
most rigorous steps and will generate the appropriate results given the range of factors that
define erodibility. The transitional/ intermediate bed procedure takes into account that bed
material may fall within the labile category (the bed material size is used in SCCWRP's Form 3
Figure 4), but other factors may trend towards a less erodible condition. Dr. Eric Stein from
SCCWRP, who co-authored the Hydromod/Ication Screening Tools: Field Manual in the Final
Hydromod/Ication Management Plan (HUT), indicated that it would be appropriate to analyze
channels with multiple factors that impact erodibility using the transitional/intermediate bed
procedure. Consequently, this procedure was used to produce more accurate results for each
study reach.
Transitional/intermediate beds cover a wide susceptibility/potential response range and need to
be assessed in greater detail to develop a weight of evidence for the appropriate screening rating.
The three primary risk factors used to assess vertical susceptibility for channels with
transitional/intermediate bed materials are:
Armoring potential - three states (Checklist 1)
Grade control - three states (Checklist 2)
Proximity to regionally-calibrated incision/braiding threshold (Mobility Index Threshold
- Probability Diagram)
These three risk factors are assessed using checklists and a diagram (see Appendix B), and the
results of each are combined to provide a final vertical susceptibility rating for the
intermediate/transitional bed-material group. Each checklist and diagram contains a Category A,
B, or C rating. Category A is the most resistant to vertical changes while Category C is the most
susceptible.
Checklist 1 determines armoring potential of the channel bed. The channel bed along each of the
twelve reaches is within category B, which represents intermediate bed material within unknown
armoring potential due to a surface veneer and dense vegetation. The soil was probed and
penetration was relatively difficult through the underlying layer of each reach. Due to the dense
vegetative growth in some reaches, the armoring potential could have been rated higher in those
reaches, but Category B was conservatively (i.e., more potential for channel incision) chosen.
Checklist 2 determines grade control characteristics of the channel bed. SCCWRP states that
grade controls can be natural. Examples are vegetation or confluences with a larger waterbody.
As indicated above and verified with photographs, Reaches El through E4, E8, and Wi through
W4 contain dense vegetation (see the figures). The plant roots and tree trunks serve as a natural
grade control. The spacing of these is much closer than the 50 meters or 2/Si, values identified in
9
the checklist. Further evidence of the effectiveness of the natural grade controls is the absence of
headcutting and mass wasting (large vertical erosion of a channel bank). Based on this
information, Reaches El through E4, E8, and Wl through W4 are within Category A on
Checklist 2.
Reaches E5 through E7 do not contain dense vegetation. However, each of these reaches has a
grade control at their downstream end. For Reach E5, the existing concrete-lined access road
crossing of the natural channel (see Figure 13)is a permanent grade control. For Reaches E6 and
E7, the existing 8-foot by 8-foot RCB under El Camino Real is a permanent grade control (see
Study Area Exhibit). Table 2 summarizes the length, 2/Sw, and 4/Sw values for each of these
reaches. Table 2 shows that for each reach, the reach length is less than the 2/Sw value (and
naturally also less than 4/Sw). Therefore, the grade control spacing in each of the three reaches is
less than 2/Sw and each reach is within Category A on Checklist 2.
Study Reach Reach Length, ft 2/Sw, ft 4/Sw, ft
E5 250 713 1,426
E6 284 745 1,491
El 603 1,099 2,198
Table 2. Grade Control Spacing Data
The Screening Index Threshold is a probability diagram that depicts the risk of incising or
braiding based on the potential stream power of the valley relative to the median particle
diameter. The threshold is based on regional data from Dr. Howard Chang of Chang Consultants
and others. The probability diagram is based on d50 as well as the Screening Index determined in
the initial desktop analysis (see Appendix A). d50 is derived from field conditions. As discussed
above, the equivalent grain size for the densely-vegetated channels in Reaches El through E4,
E8, and Wi through W4 is at least 64 mm. The Screening Index Threshold diagram shows that
the 50 percent probability of incising or braiding for a d50 of 64 mm has an index of at least
0.101 (in red rectangle on diagram). The Screening Index for these nine reaches calculated in
Appendix A varies from 0.009 to 0.039. Since each reach's Screening Index value is less than
the 50 percent value, Reaches El through E4, E8, and Wi through W4 fall within Category A.
For Reaches E5 through El, their D50 value was entered onto the Screening Index Threshold
graph. As mentioned above, a pebble count determined that the D50 for each of these reaches is
11 mm. Plotting 11 mm on the graph corresponds to a 50 percent Screening Index value of
0.03 8. The Screening Index calculated in Appendix A for the three reaches varies from 0.0 11 to
0.023. Since each reach's Screening Index value is less than the 50 percent value, Reaches E5,
E6, and El fall within Category A.
The overall vertical rating is determined from the Checklist 1, Checklist 2, and Mobility Index
Threshold results. The scoring is based on the following values:
Category A =3, Category B =6, Category C = 9
The vertical rating score for each of the twelve reaches is based on these values and the equation:
10
Vertical Rating = [(armoring x grade control)" x screening index score] 112
= [(6 x 3)1/2 x 3]1/2 (Note: each of the twelve reaches has similar values)
=3.6
Since the vertical rating is less than 4.5, each reach has a low vertical susceptibility to erosion.
Lateral Stability
The purpose of the lateral decision tree (Figure 6-5 from County of San Diego HIvIP included in
Figure 31) is to assess the state of the channel banks with a focus on the risk of widening.
Channels can widen from either bank failure or through fluvial processes such as chute cutoffs,
avulsions, and braiding. Widening through fluvial avulsions/active braiding is a relatively
straightforward observation. If braiding is not already occurring, the next logical step is to assess
the condition of the banks. Banks fail through a variety of mechanisms; however, one of the most
important distinctions is whether they fail in mass (as many particles) or by fluvial detachment of
individual particles. Although much research is dedicated to the combined effects of weakening,
fluvial erosion, and mass failure, SCCWRP found it valuable to segregate bank types based on
the inference of the dominant failure mechanism (as the management approach may vary based
on the dominant failure mechanism). A decision tree (Form 4 in Appendix B) is used in
conducting the lateral susceptibility assessment. Definitions and photographic examples are also
provided below for terms used in the lateral susceptibility assessment.
The first step in the decision tree is to determine if lateral adjustments are occurring. The
adjustments can take the form of extensive mass wasting (greater than 50 percent of the banks
are exhibiting planar, slab, or rotational failures and/or scalloping, undermining, and/or tension
cracks). The adjustments can also involve extensive fluvial erosion (significant and frequent
bank cuts on over 50 percent of the banks). Neither mass wasting nor extensive fluvial erosion
was evident within any of the reaches during a field investigation. The banks are intact in the
photographs included in the figures. Due to the dense vegetation in most areas, photographs
representative of the banks were difficult to take. Nonetheless, the dense vegetation supports the
absence of large lateral adjustments.
The next step in the Form 4 decision tree is to assess the consolidation of the bank material. The
banks were moderate to well-consolidated. This determination was made because the banks were
difficult to penetrate with a probe. In addition, the banks showed limited evidence of crumbling
and were composed of well-packed particles.
Form 6 (see Appendix B) is used to assess the probability of mass wasting. Form 6 identifies a
10, 50, and 90 percent probability based on the bank angle and bank height. The 2-foot contour
interval topographic mapping indicates that the average natural bank angle is no greater than 2 to
1 (horizontal to vertical) or 26.6 degrees in any of the reaches. Form 6 shows that the probably of
mass wasting and bank failure has less than 10 percent risk for a 26.6 degree bank angle or less
regardless of the bank height.
The final two steps in the Form 4 decision tree are based on the braiding risk determined from
the vertical rating as well as the Valley Width Index (VWI) calculated in Appendix A. If the
11
vertical rating is high, the braiding risk is considered to be greater than 50 percent. Excessive
braiding can lead to lateral bank failure. For all 12 study reaches, the vertical rating is low, so the
braiding risk is less than 50 percent. Furthermore, a VWI greater than 2 represents channels
unconfined by bedrock or hillslope and, hence, subject to lateral migration. The VWI
calculations in the spreadsheet in Appendix A show that the VWI for each reach is less than 2.
From the above steps, the lateral susceptibility rating is low for each of the twelve study reaches
(red circles are included on the Form 4: Lateral Susceptibility Field Sheet decision tree in
Appendix B showing the decision path). A review of aerial photographs confirms a lack of
braiding or lateral migration throughout the natural channels.
CONCLUSION
The SCCWRP channel screening tools were used to assess the downstream channel
susceptibility for the Rancho Costera and associated El Camino Real Widening projects being
designed by O'Day Consultants, Inc. The project runoff will ultimately be collected by a series
of proposed and/or existing storm drain systems that outlet into unnamed natural channels at
various locations along the easterly and westerly portions of the developments. Each outlet is a
point of compliance. Based on the points of compliance, the unnamed natural channels were
assessed from the upstream-most POCs to either the confluence with Agua Hedionda Creek or
the concrete-lined Kelly Drive trapezoidal channel (domain of analysis). The assessment was
performed based on office analyses and field work. The results indicate a low susceptibility for
vertical and lateral channel erosion for the entire study area.
The HMP requires that these results be compared with the critical stress calculator results
incorporated in the County of San Diego's BMP Sizing Calculator. The BMP Sizing Calculator
critical stress results are included in Appendix B for all twelve reaches. Based on these values,
the critical stress results returned a low susceptibility to erosion. Therefore, the SCCWRP
analyses and critical stress calculator demonstrate that the project can be designed assuming a
low susceptibility, i.e., 0.5Q2.
The SCCWRP results are consistent with the physical condition of the natural channel within the
domain of analysis, which is moderately to densely-vegetated throughout. None of the twelve
study reaches exhibit signs of extensive, ongoing erosion.
12
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25
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Figure 27. Gravelometer within Reach E5
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27
APPENDIX A
SCCWRP INITIAL DESKTOP ANALYSIS
FORM 1: INITIAL DESKTOP ANALYSIS
Complete all shaded sections.
IF required at multiple locations, circle one of the following site types:
Applicant Site I Upstream Extent / Downstream Extent
Location: Latitude: I 33.154 I Longitude:I -117.3040 1.
Description (river name, crossing streets, etc.): I Rancho Costera (north of El Camind
Real between Tamarack Ave. and Cannon Rd.) and El Camino Real widenin.
GIS Parameters: The International System of Units (SI) is used throughout the assessment as the field
standard and for consistency with the broader scientific community. However, as the singular exception, US
Customary units are used for contributing drainage area (A) and mean annual precipitation (P) to apply regional flow
equations after the USGS. See SCCWRP Technical Report 607 for example measurements and"Screening Tool
Data Entrv.xls" for automated calculations.
Form I Table 1. Initial desktop analysis in GIS.
Symbol Variable Description and Source Value
A Area Contributing drainage area to screening location via published
(mi) Hydrologic Unit Codes (HUCs) and/or :s 30 rn National Elevation Data
(NED), USGS seamless server
2 P
CL a
Mean annual Area-weighted annual precipitation via USGS delineated polygons using precipitation records from 1900 to 1960 (which was more significant in hydrologic See attached
(in) models than polygons delineated from shorter record lengths) Form 1 table
S Valley slope Valley slope at site via NED, measured over a relatively homogenous on next page
(rn/rn) valley segment as dictated by hillslope configuration, tributary for calculated
confluences, etc., over a distance of up to -500 rn or 10% of the main- values for each channel length from site to drainage divide -reach
W Valley width Valley bottom width at site between natural valley walls as dictated by CL U5
(m) clear breaks in hillslope on NED raster, irrespective of potential
Cl) armoring from floodplain encroachment, levees, etc. (imprecise
measurements have negligible effect on rating in wide valleys where
VWI is >> 2, as defined in lateral decision tree)
Form I Tabi e 2. Simplif led peak fib w, screening index, and valley width index. Values for this
table should be calculated in the sequence shown in this table, using values from Form I Table 1.
Symbol Dependent Variable Equation Required Units Value
Q10da 10-yr peak flow (ft3ls) Qio = 18.2 * A 0.87 * p 0.77
10-yr peak flow (m3/s) Qio = 0.0283 * Qioefs
10-yr screening index (rn15/s°) INDEX = S*Qio 0.5
Qio
INDEX
Wref
VWI
Reference width (rn)
Valley width index (rn/rn)
W,f = 6.99 * Qio 0.438
VWI = Wvfwref
A (mi)
P (in)
Qiods (ft3/s)
Sv (m/m)
Q10 (rn/s)
Qia (rn3/s)
W, (rn)
Wref (m)
See attached
Form I table'
on next page
for calculatd
values for each
reach.
(Sheet I of I)
B-3
SCCWRP FORM 1 ANALYSES
Area Mean Annual Precip. Valley Slope Valley Width 10-Year Flow 10-Year Flow
Reach A, sq. mi. P, inches Sv, rn/rn Wv, m Qlocfs, cfs Q10, cms
El 0.2400 13.3 0.0289 6.1 39 1.1
E2 0.0731 13.3 0.0551 1.5 14 0.4
E3 0.0732 13.3 0.0369 1.5 14 0.4
E4 0.1272 13.3 0.0247 8.5 22 0.6
E5 0.3963 13.3 0.0092 11.0 60 1.7
E6 0.3964 13.3 0.0088 4.6 60 1.7
E7 4.6800 13.3 0.0060 16.8 511 14.5
E8 5.1100 13.3 0.0091 25.9 552 15.6
Wi 0.0054 13.3 0.0448 2.4 1 0.04
W2 0.8078 13.3 0.0191 6.1 ill 3.1
W3 1.1157 13.3 0.0127 17.7 147 4.2
W4 1.2688 13.3 0.0183 4.9 164 4.6
10-Year Screening Index Reference Width Valley Width Index
Reach INDEX Wref, rn VWI, rn/rn
El 0.030 7.3 0.84
E2 0.034 : 4.6 0.33
E3 0.023 4.6 0.33
E4 0.020 5.7 1.50
ES 0.012 8.8 1.25
E6 0.011 8.8 0.52
E7 0.023 22.5 0.74
E8 0.036 23.3 1.11
Wi 0.009 1.7 1.42
W2 0.034 11.5 0.53
W3 0.026 13.0 1.36
W4 0.039 13.7 0.36
nap Details
Result View
flfl:L Define Drainage Basins Agua Hedionda Watershed Project Ranch Costera & El Camino Real Widening
L] L BasinJ
Manage Your Basins
Create a new Basin by clicking the New button and scroll down to view
entry Alternatively, select an existing Basin from table and view
properties below- Click Edit button to change Basin properties then
press Save to commit changes.
lF
Agua Hedionda Watershed
Name
Description: IRancho Costera & ECR Drainage Basins Point of Compliance: Ivarious Storm Drain Outfalls
Design Goal: Treatment + Flow Control Project Basin Area (ac): 1429
Rainfall Basin: loceanside Mean Annual Precipitlon (In): F13.3 I
PEBBLE COUNT
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
Reach E5 Diameter, mm
2
2
2
2
2
2.8
2.8
2.8
2.8
2.8
4
4
4
4
4
4
4
4
4
4
4
4
4
5.6
5.6
5.6
5.6
5.6
5.6
5.6
5.6
5.6
5.6
5.6
8
8
8
8
8
8
8
8
8
8
Reach E6 Diameter, mm
2
2
2
2
2
2
2
2
2
2.8
2.8
2.8
2.8
2.8
2.8
2.8
2.8
2.8
4
4
4
4
4
4
4
4
4
4
5.6
5.6
5.6
5.6
5.6
5.6
5.6
5.6
5.6
5.6
5.6
5.6
5.6
5.6
8
8
Reach [7 Diameter, mm
2
2
2
2
2
2
2
2
2.8
2.8
2.8
2.8
2.8
2.8
2.8
2.8
4
4
4
4
4
4
4
4
4
4
4
4
5.6
5.6
5.6
5.6
5.6
5.6
5.6
8
8
8
8
8
8
8
8
8
Reach E5 Diameter, mm Reach E6 Diameter, mm Reach E7 Diameter, mm
45 8 8 11
46 8 8 11
47 8 8 11
48 11 8 11
49 11 11 11
Iso ii 11 11
51 11 11 11
52 11 11 11
53 11 11 11 -
54 11 11 11
55 11 11 11
56 11 11 11
57 11 11 16
58 11 11 16
59 11 11 16
60 11 11 16
61 11 11 16
62 11 11 16
63 11 11 16
64 11 11 16
65 11 16 16
66 11 16 16
67 16 16 16
68 16 16 16
69 16 16 16
70 16 16 16
71 16 16 16
72 16 16 16
73 16 16 16
74 16 16 16
75 16 16 16
76 16 16 16
77 16 16 16
78 16 16 16
79 16 16 16
80 16 16 16
81 16 16 16
82 16 16 16
83 16 16 16
84 16 16 16
85 16 16 22.6
86 16 16 22.6
87 16 16 22.6
88 16 16 22.6
89 16 22.6 22.6
90 16 22.6 22.6
91
92
93
94
95
96
97
98
99
100
Reach E5 Diameter, mm
22.6
22.6
22.6
22.6
22.6
22.6
22.6
22.6
32
32
Reach E6 Diameter, mm
22.6
22.6
22.6
22.6
22.6
22.6
22.6
32
32
32
Reach El Diameter, mm
22.6
22.6
22.6
22.6
32
32
32
32
32
64
Maximum flow rates at confluence using above data:
37.976 22.996 40.432 49.662
Area of streams before confluence:
5.550 1.210 2.000 26.600
Results of confluence:
Total flow rate = 49.662(CFS.)
Time of concentration = 20.000 mm.
Effective stream area after confluence = 35.360 (Ac.)
Process from Point/Station 210.000 to Point/Station 214.000
IRREGULAR CHANNEL FLOW TRAVEL TIME ****
Estimated mean flow rate at midpoint of channel = 53.019(CFS)
Depth of flow = 1.519(Ft.), Average velocity = 7.657(Ft/s)
Irregular Channel Data ***********
-----------------------------------------------------------------
Information entered for s.thchanne1 number 1
Point number 'X' coordinate 'Y' coordinate
1 0.00 10.00
2 30.00 0.00
3 60.00 10.00
Manning's 'N' friction factor 0.035 -----------------------------------------------------------------
Sub-Channel flow = 53.019(CFS)
flow top width = 9.115(Ft.)
velocity= 7.657 (Ft/a)
area = 6.924(Sq.Ft)
Froude number = 1.548
Upstream point elevation = 142.000(Ft.)
Downstream point elevation = 70.000(Ft.)
Flow length = 1430.000(Ft.)
Travel time = 3.11 mm.
Time of concentration = 23.11 min.
Depth of flow = 1.519 (Ft.)
Average velocity = 7.657 (Ft/a)
Total irregular channel flow = 53.019(CFS)
Irregular channel normal depth above invert elev. = 1.519 (Ft.)
Average velocity of channel(s) = 7.657 (Ft/a)
Adding area flow to channel
Rainfall intensity (I) = 2.552(In/Hr) for a 100.0 year storm
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
(UNDISTURBED NATURAL TERRAIN
(Permanent Open Space
Impervious value, Ai = 0.000
Sub-Area C Value = 0.350
Rainfall intensity = 2.552(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.471 CA = 22.060
VA
Subarea runoff = 6.634(CFS) for 11.500 (Ac.)
_________ Total runoff = 56.296(CFS) 1 area (6860j()) Reach E3
Depth of flow = 1.554(Ft.), Average velocity = 7.773(Ft/s)
Note: Reach E2 = 46.86 - 0.1 = 46.76 Acres
Process from Point/Station 214.000 to Point/Station 216.000
**** PIPEFLOW TRAVEL TIME (User specified size)
Upstream point/station elevation = 70.000 (Ft.)
Downstream point/station elevation = 60.000 (Ft.)
Pipe length = 250.00(Ft.) Slope = 0.0400 Manning's N = 0.015
No. of pipes = 1 Required pipe flow = 56.296(CFS)
Given pipe size = 30.00 (In.)
Calculated individual pipe flow = 56.296(CFS)
Normal flow depth in pipe = 20.16 (In.)
Flow top width inside pipe = 28.17 (In.)
Critical Depth = 28.38(In.)
Pipe flow velocity = 16.06 (Ft/s)
Travel time through pipe = 0.26 mm.
Time of concentration (TC) = 23.37 mm.
Process from Point/Station 214.000 to Point/Station 216.000
CONFLUENCE OF MAIN STREAMS
The following data inside Main Stream is listed:
In Main Stream number: 1
Stream flow area = 46.860 (Ac.)
Runoff from this stream = 56.296(CFS)
Time of concentration = 23.37 mm.
Rainfall intensity = 2.534(In/Hr)
Program is now starting with Main Stream No. 2
Process from Point/Station 218.000 to Point/Station 222.000
INITIAL AREA EVALUATION ****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C =0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less
Impervious value, Ai = 0.650
Sub-Area C Value = 0.710
Initial subarea total flow distance = 100.000(Ft.)
Highest elevation = 130.500(Ft.)
Lowest elevation = 128.700(Ft.)
Elevation difference = 1.800(Ft.) Slope = 1.800 %
Top of Initial Area Slope adjusted by User to 0.740 %
Bottom of Initial Area Slope adjusted by User to 0.740 %
8
area = 30.066(Sq.Ft)
Froude number = 1.057
Upstream point elevation = 60.000(Ft.)
Downstream point elevation = 42.000(Ft.)
Flow length = 600.000(Ft.)
Travel time = 3.07 mm.
Time of concentration = 26.44 mm.
Depth of flow = 0.298 (Ft.)
Average velocity = 3.260(Ft/s)
Total irregular channel flow = 97.999(CFS)
Irregular channel normal depth above invert elev. = 0.298 (Ft.)
Average velocity of channel(s) = 3.260 (Ft/B)
Process from Point/Station 216.000 to Point/Station 2009.000
SUBAREA FLOW ADDITION ****
Rainfall intensity (I) = 2.340(In/Hr) for a 100.0 year storm
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[UNDISTURBED NATURAL TERRAIN
(Permanent Open Space
Impervious value, Ai = 0.000
Sub-Area C Value = 0.350
The area added to the existing stream causes a
a lower flow rate of Q = 93.650(CFS)
therefore the upstream flow rate of Q = 97.999(CFS) is being used
Time of concentration = 26.44 mm.
Rainfall intensity = 2.340(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.492 CA = 40.024
Subarea runoff = 0.000(CFS) for 4.850 (Ac.)
Total runoff = 97.999(CFS) (Total _area--) (81.430(Ac.)) Reach E4
Process from Point/Station 216.000 to Point/Station 2009.000
**** CONFLUENCE OF MAIN STREAMS ****
The following data inside Main Stream is listed:
In Main Stream number: 1
Stream flow area = 81.430 (Ac.)
Runoff from this stream = 97.999(CFS)
Time of concentration = 26.44 mm.
Rainfall intensity = 2.340(In/Hr)
Program is now starting with Main Stream No. 2
Process from Point/Station 254.000 to Point/Station 254.000
20
Area of streams before confluence:
114.250 19.180
Results of confluence:
Total flow rate = 163.679(CFS)
Time of concentration = 20.880 mm.
Effective stream area after confluence = 133.430 (Ac.)
Process from Point/Station 272.000 to Point/Station 2009.000
IRREGULAR CHANNEL FLOW TRAVEL TIME ****
Estimated mean flow rate at midpoint of channel = 163.727(CFS)
Depth of flow = 0.727(Ft.), Average velocity = 4.344(Ft/s)
******* Irregular Channel Data ***********
-----------------------------------------------------------------
Information entered for subchannel number 1
Point number IX, coordinate 'Y' coordinate
1 0.00 10.00
2 30.00 0.00
3 80.00 0.00
4 100.00 10.00
Manning's 'N' friction factor = 0.035 -----------------------------------------------------------------
Sub-Channel flow = 163.728(CFS)
flow top width = 53.637(Ft.)
velocity= 4.344(Ft/s)
area = 37.692(Sq.Ft)
Froude number = 0.913
Upstream point elevation = 69.000(Ft.)
Downstream point elevation = 42.000(Ft.)
Flow length = 1600.000(Ft.)
Travel time = 6.14 mm.
Time of concentration = 27.02 min.
Depth of flow = 0.727 (Ft.)
Average velocity = 4.344(Ft/s)
Total irregular channel flow = 163.727(CFS)
Irregular channel normal depth above invert elev. = 0.727 (Ft.)
Average velocity of channel(s) = 4.344(Ft/s)
Adding area flow to channel
Rainfall intensity (I) = 2.307(In/Hr) for a 100.0 year storm
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
(UNDISTURBED NATURAL TERRAIN ]
(Permanent Open Space )
Impervious value, Al = 0.000
Sub-Area C Value = 0.350
The area added to the existing stream causes a
a lower flow rate of Q = 151.902(CFS)
therefore the upstream flow rate of Q = 163.679(CFS) is being used
Rainfall intensity = 2.307(In/Hr) for a 100.0 year storm
36
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.429 CA = 65.833
Subarea runoff = 0.000 (CFS) for - 20 . 180 (Ac.)
Total runoff = 163.679(CFS) a1area =D (53.610() Reach El
Depth of flow = 0.727(Ft.), Average velocity = 4.343(Ft/s)
Process from Point/Station 272.000 to Point/Station 2009.000
**** CONFLUENCE OF MAIN STREAMS
The following data inside Main Stream is listed:
In Main Stream number: 2
Stream flow area = 153.610 (Ac.)
Runoff from this stream = 163.679(CFS)
Time of concentration = 27.02 mm.
Rainfall intensity = 2.307(In/Hr)
Summary of stream data:
Stream Flow rate TC Rainfall Intensity
No. (CFS) (mm) (In/Hr)
1 97.999 26.44 2.340
2 163.679 27.02 2.307
Qmax(1) =
1.000 * 1.000 * 97999) +
1.000 * 0.979 * 163.679) + = 258.167
Qmax(2) =
0.986 * 1.000 * 97999) +
1.000 * 1.000 * 163.679) + = 260.317
Total of 2 main streams to confluence:
Flow rates before confluence point:
97.999 163.679
Maximum flow rates at confluence using above data:
258.167 260.317
Area of streams before confluence:
81.430 153.610
Results of confluence:
Total flow rate = 260.317(CFS)
Time of concentration = 27.019 mm.
Effective stream area after confluence = 235.040 (Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2009.000 to Point/Station 2010.000
IRREGULAR CHANNEL FLOW TRAVEL TIME ****
Estimated mean flow rate at midpoint of channel = 260.342(CFS)
Depth of flow = 0.680(Ft.), Average velocity = 3.738(Ft/s)
******* Irregular Channel Data ***********
37
Nearest computed pipe diameter = 21.00 (In.)
Calculated individual pipe flow = 24.726(CFS)
Normal flow depth in pipe = 13.66 (In.)
Flow top width inside pipe = 20.02 (In.)
Critical depth could not be calculated.
Pipe flow velocity = 14.92(Ft/s)
Travel time through pipe = 0.78 mm.
Time of concentration (TC) = 25.51 mm.
Process from Point/Station 2013.000 to Point/Station 2010.000
**** CONFLUENCE OF MINOR STREAMS ****
Along Main Stream number: 1 in normal stream number 2
Stream flow area = 12.650 (Ac.)
Runoff from this stream = 24.726(CFS)
Time of concentration = 25.51 mm.
Rainfall intensity = 2.394(In/Hr)
Summary of stream data:
Stream Flow rate TC
No. (CFS) (mm)
1 260.317 29.25
2 24.726 25.51
Qmax(1) =
Rainfall Intensity
(In/Hr)
2.192
2.394
1.000 * 1.000 * 260.317) +
0.916 * 1.000 * 24.726) + = 282.955
Qmax(2) =
1.000 * 0.872 * 260.317) +
1.000 * 1.000 * 24.726) + = 251.779
Total of 2 streams to confluence:
Flow rates before confluence point:
260.317 24.726
Maximum flow rates at confluence using above data:
282.955 251.779
Area of streams before confluence:
240.950 12.650
Results of confluence:
Total flow rate = 282.955(CFS)
Time of concentration = 29.249 mm.
Effective stream area after confluence = 253.600(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2010.000 to Point/Station 2015.000
PIPEFLOW TRAVEL TIME (User specified size)
Upstream point/station elevation = 35.300 (Ft.)
Downstream point/station elevation = 34.500(Ft.)
Pipe length = 40.00(Ft.) Slope = 0.0200 Manning's N = 0.013
41
No. of pipes = 1 Required pipe flow = 282.955(CFS)
Given pipe size = 30.00(In.)
NOTE: Normal flow is pressure flow in user selected pipe size.
The approximate hydraulic grade line above the pipe invert is
95.622(Ft.) at the headworks or inlet of the pipe(s)
Pipe friction loss = 19.029(Ft.)
Minor friction loss = 77.393(Ft.) K-factor = 1.50
Critical depth could not be calculated.
Pipe flow velocity = 57.64 (Ft/s)
Travel time through pipe = 0.01 mm.
Time of concentration (TC) 29.26 mm.____
End of computations, total study area = (253 .600) ((Ac.)) Reach E5
Note: Reach E6 = 253.6 + 0.1 = 253.7 Acres
42
APPENDIX 4
100 Yr. Proposed Hydrologic Calculations
Basin 'E-F'
(See Exhibit 'K')
Process from Point/Station 5000.000 to Point/Station 5000.000
**** CONFLUENCE OF MAIN STREAMS
The following data inside Main Stream is listed:
In Main Stream number: 1
Stream flow area = 509.400 (Ac.)
Runoff from this stream = 512.740(CFS)
Time of concentration = 31.46 mm.
Rainfall intensity = 2.092(In/Hr)
Program is now starting with Main Stream No. 2
+++++++++++++++++++++++++++++++++++++++++++++++++++++-f-++++++++++++++++
Process from Point/Station 5002.000 to Point/Station 5004.000
INITIAL AREA EVALUATION
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[UNDISTURBED NATURAL TERRAIN ]
(Permanent Open Space
Impervious value, Al = 0.000
Sub-Area C Value = 0.350
Initial subarea total flow distance = 100.000(Ft.)
Highest elevation = 180.000(Ft.).
Lowest elevation = 130.000(Ft.)
Elevation difference = 50.000(Ft.) Slope = 50.000 %
Top of Initial Area Slope adjusted by User to 30.000 %
INITIAL AREA TIME OF CONCENTRATION. CALCULATIONS:
The maximum overland flow distance is 100.00 (Ft)
for the top area slope value of 30.00 %, in a development type of
Permanent Open Space
In Accordance With Figure 3-3
Initial Area Time of Concentration = 4.34 minutes
TC = [1.8*(1.l_C)*distánce(Ft.)'.5)/(% s1ope'(1/3)]
TC = [1.8*(1.1_0.3500)*( 100.000'.5)/( 30.000"(1/3)]= 4.34
Calculated TC of 4.345 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations
Rainfall intensity (I) = 6.850(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for area (Q=KCIA) is C = 0.350
Subarea runoff = 0.240(CFS)
Total initial stream area = 0.100 (Ac.)
Process from Point/Station 5004.000 to Point/Station 5006.000
lc1c* IMPROVED CHANNEL TRAVEL TIME
Upstream point elevation = 130.000 (Ft.)
Downstream point elevation = 63.000 (Ft.)
Channel length thru subarea = 700.000 (Ft.)
Channel base width = 1.000 (Ft.)
Slope or 'Z' of left channel bank= 2.000
Slope or 'Z' of right channel bank = 2.000
Estimated mean flow rate at midpoint of channel = 3.659(CFS)
Manning's 'N' = 0.035
Maximum depth of channel = 2.000 (Ft.)
Flow(q) thru subarea = 3.659(CFS)
Depth of flow = 0.391(Ft.), Average velocity = 5.259(Ft/s)
Channel flow top width = 2.563 (Ft.)
Flow Velocity = 5.26 (Ft/s)
Travel time = 2.22 mm.
Time of concentration = 6.56 mm.
Critical depth = 0.531(Ft.)
Adding area flow to channel
Rainfall intensity (I) = 5.748(In/Hr) for a 100.0 year storm
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[UNDISTURBED NATURAL TERRAIN
(Permanent Open Space )
Impervious value, Ai = 0.000
Sub-Area C Value = 0.350
Rainfall intensity = 5.748(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.350 CA = 1.214
Subarea runoff = 6.741(CFS) for 3.370(Ac.)
Total runoff = 6.981(CFS) TIarea1J f3O)) Reach WI
Depth of flow = 0.538(Ft.), Average velocity = 6.247(Ft/s)
Critical depth = 0.734 (Ft.)
Process from Point/Station 5006.000 to Point/Station 5008.000
PIPEFLOW TRAVEL TIME (User specified size) ****
Upstream point/station elevation = 63.000(Ft.)
Downstream point/station elevation = 61.800 (Ft.)
Pipe length = 68.00(Ft.) Slope = 0.0176 Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 6.981(CFS)
Given pipe size = 18.00(In.)
Calculated individual pipe flow = 6.981(CFS)
Normal flow depth in pipe = 9.00 (In.)
Flow top width inside pipe = 18.00 (In.)
Critical Depth = 12.28(In.)
Pipe flow velocity = 7.90(Ft/s)
Travel time through pipe = 0.14 rain.
Time of concentration (TC) = 6.71 rain.
Process from Point/Station 5008.000 to Point/Station 5000.000
IMPROVED CHANNEL TRAVEL TIME
Upstream point elevation = 61.800 (Ft.)
Downstream point elevation = 57.000 (Ft.)
3
1 512.740
2 6.981
Qmax(1) =
1.000
0.429
Qmax(2) =
1.000
1.000
31.46 2.092
8.48 4.873
* 1.000 * 512.740) +
* 1.000 * 6.981) + =
* 0.269 * 512.740) +
* 1.000 * 6.981) + =
515.736
145.135
Channel length thru subarea = 330.000 (Ft.)
Channel base width = 1.000 (Ft.)
Slope or 'Z' of left channel bank = 2.000
Slope or 'Z' of right channel bank = 2.000
Manning's 'N' = 0.035
Maximum depth of channel = 2.000 (Ft.)
Flow(q) thru subarea = 6.981(CFS)
Depth of flow = 0.839(Ft.), Average velocity =
Channel flow top width = 4.356 (Ft.)
Flow Velocity = 3.11 (Ft/s)
Travel time = 1.77 mm.
Time of concentration = 8.48 mm.
Critical depth = 0.734 (Ft.)
3.107(Ft/s)
++++++++++++++++++..++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 5008.000 to Point/Station 5000.000
CONFLUENCE OF MAIN STREAMS
The following data inside Main Stream is listed:
In Main Stream number: 2
Stream flow area = 3.470 (Ac.)
Runoff from this stream = 6.981(CFS)
Time of concentration = 8.48 mm.
Rainfall intensity = 4.873(In/Hr)
Summary of stream data:
Stream Flow rate TC
No. (CFS) (mm)
Rainfall Intensity
(In/Hr)
Total of 2 main streams to confluence:
Flow rates before confluence point:
512.740 6.981
Maximum flow rates at confluence using above data:
515.736 145.135
Area of streams before confluence:
509.400 3.470
Results of confluence:
Total flow rate = 515.736(CFS)
Time of concentration = 31.460 min.
Effective stream area after confluence = (512.870(Ac.)) Reach W2
(northerly subarea)
4
Depth of flow = 0.299(Ft.), Average velocity = 1.911(Ft/s)
Streetfiow hydraulics at midpoint of street travel:
Halfstreet flow width = 8.129 (Ft.)
Flow velocity = 1.91 (Ft/s)
Travel time = 3.14 mm. TC = 9.39 mm.
Adding area flow to Street
Rainfall intensity (I) = 4.562(In/Hr) for a 100.0 year storm
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[MEDIUM DENSITY RESIDENTIAL
(7.3 DTJ/A or Less
Impervious value, Ai.= 0.400
Sub-Area C Value = 0.570
Rainfall, intensity = 4.562(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.570 CA = 1.180
Subarea runoff = 5.044(CFS) for 1.970(Ac.)
Total runoff = 5.382(CFS) Total area = 2.070 (Ac.)
Street flow at end of street = 5.382(CFS)
Half Street flow at end of street = 2.691(CFS)
Depth of flow = 0.348(Ft.), Average velocity = 2.200(Ft/s)
Flow width (from curb towards crown)= 10.586(Ft.)
Process from Point/Station 5017.000 to Point/Station 5014.000
PIPEFLOW TRAVEL TIME (User specified size)
Upstream point/station elevation = 135.500 (Ft.)
Downstream point/station elevation = 79.050 (Ft.)
Pipe length = 510.00(Ft.) Slope = 0.1107 Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 5.382(CFS)
Given pipe size = 18.00(In.)
Calculated individual pipe flow = 5.382(CFS)
Normal flow depth in pipe = 4.78(m.)
Flow top width inside pipe = 15.89(Th.)
Critical Depth = 10.73(In.)
Pipe flow velocity = 14.33 (Ft/s)
Travel time through pipe = 0.59 min.
Time of concentration (TC) = 9.98 mm.
+++++++.++++++++++++++++.+++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 5017.000 to Point/Station 5014.000
CONFLUENCE OF MINOR STREAMS
Along Main Stream number: 2 in normal stream number 2
Stream flow area = 2.070 (Ac.)
Runoff from this stream = 5.382(CFS)
Time of' concentration = 9.98 mm.
Rainfall intensity = 4.385'(In/Hr)
Summary of stream data:
9
Stream Flow rate TC Rainfall Intensity
No. (CFS) (mm) (In/Hr)
1 4.498 5.73 6.276
2 5.382 9.98. 4.385
Qmax(1) =
1.000 * 1.000 * 4.498) +
1.000 * 0.574 * 5.382) + = 7.586
Qmax(2) =
0.699 * 1.000 * 4.498) +
1.000 * 1.000 * 5.382) + = 8.526
Total of 2 streams to confluence:
Flow rates before confluence point:
4.498 5.382
Maximum flow rates at confluence using above data:
7.586 8.526
Area of streams before confluence:
2.040 2.070
Results of confluence:
Total flow rate = 8.526(CFS)
Time of concentration = 9.984 min. Reach W2 (Effective stream area after confluence) 4.110(Ac (easterly subarea)
Total Area of Reach W2 is northerly + easterly subarea.
Process from Point/Station 5014.000 to Point/Station 5018.000
PIPEFLOW TRAVEL TIME (User specified size) ****
Upstream point/station elevation = 79.050 (Ft.)
Downstream point/station elevation = 60.000(Ft.)
Pipe length = 96.00(Ft.) Slope = 0.1984 Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 8.526(CFS)
Given pipe size = 18.00 (In.)
Calculated individual pipe flow = 8.526(CFS)
Normal flow depth in pipe z 5.20(m.)
Flow top width inside pipe = 16.32 (In.)
Critical Depth = 13.57 (In.)
Pipe flow velocity = 20.14(Ft/s).
Travel time through pipe = 0.08 mm.
Time of concentration (TC) = 10.06 mm.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 5018.000 to Point/Station 5010.000
IMPROVED CHANNEL TRAVEL TIME r
Upstream point elevation = 60.000(Ft.)
Downstream point elevation = 51.000 (Ft.)
Channel length thru subarea = 460.000 (Ft.)
Channel base width = 1.000 (Ft.)
Slope or 'Z' of left channel bank = 2.000
10
-----------------------------------------------------------------
Sub-Channel flow = 22.805(CFS)
I flow top width = 7.226(Ft.)
I I velocity= 3.494(Ft/s)
area = 6.527(Sq.Ft)
Froude number = 0.648
Upstream point elevation = 43.620(Ft.)
Downstream point elevation = 42.000(Ft.)
Flow length = 180.000(Ft.)
Travel time = 0.86 mm.
Time of concentration = 9.93 mm.
Depth of flow = 1.807 (Ft.)
Average velocity = 3.494(Ft/s)
Total irregular channel flow = 22.805(CFS)
Irregular channel normal depth above invert elev. = 1.807 (Ft.)
Average velocity of channel(s) = 3.494(Ft/s)
Process from Point/Station 5050.000 to Point/Station 5034.000
CONFLUENCE OF MAIN STREAMS
The following data inside Main Stream is listed:
In Main Stream number: 2
Stream flow area = 6.610(Ac.)
Runoff from this stream = 22.805(CFS)
Time of concentration = 9.93 mm.
Rainfall intensity = 4.402(In/Hr)
Summary of stream data:
Stream Flow rate TC Rainfall Intensity
No. (CFS) (mm) (In/Hr)
1 719.611 35.74 1.926
2 22.805 9.93 4.402
Qmax (1)
1.000 * 1.000 * 719.611) +
0.438 * 1.000 * 22.805) + = 729.591
Qmax (2)
1.000 * 0.278 * 719.611) +
1.000 * 1.000 * 22.805) + = 222.633
Total of 2 main streams to confluence:
Flow rates before confluence point:
719.611 22.805
Maximum flow rates at confluence using above data:
729.591 222.633
Area of streams before confluence:
707.440 6.610
Results of confluence:
21
Total flow rate = 729.591(CFS)
Time of concentration = 35.742 mm. ___________
(Effective stream area after confluence) (714.050(Ac.) Reach W3
+++++++++++++++++++++++++.++++++++++.+++.+++.+++++++.++++++++++++++++++
Process from Point/Station 5034.000 to Point/Station 5052.000
IMPROVED CHANNEL TRAVEL TIME EXISTING DOUBLE 8'X4' RCB
Covered channel
Upstream point elevation = 42.000 (Ft.)
Downstream point elevation = 40.000(Ft.)
Channel length thru subarea = 108.000 (Ft.)
Channel base width = 16.000 (Ft.)
Slope or 'Z' of left channel bank = 0.000
Slope or 'Z' of right channel bank = 0.000
Manning's 'N' = 0.015
Maximum depth of channel = 4.000 (Ft.)
Flow(q) thru subarea = 729.591(CFS)
Depth of flow = 2.298 (Ft.), Average velocity =
Channel flow top width = 16.000(Ft.)
Flow Velocity = 19.84(Ft/s)
Travel time = 0.09 mm.
Time of concentration = 35.83 mm.
Critical depth = 4.000 (Ft.)
izT'.T c-Es.
19.840(Ft/s)
+.+++++++++++++++++++++++++++++++++++++++++++++++.++.++++++++++++.++++
Process from Point/Station 5034.000 to Point/Station 5052.000
**** CONFLUENCE OF MAIN STREAMS
The following data inside Main Stream is listed:
In Main Stream number: 1
Stream flow area = 714.050(Ac.)
Runoff from this stream = 729.591(CFS)
Time of concentration = 35.83 mm.
Rainfall intensity = 1.923(In/Hr)
Program is now starting with Main Stream No. 2
++++++++++++++.++++++++++++++++++++++++++++++++++++++++++++++++.++++++
Process from Point/Station 7000.000 to Point/Station 7007.000
USER DEFINED FLOW INFORMATION AT A POINT
User specified 'C' value of 0.700 given for subarea
Rainfall intensity (I) = 3.229(In/Hr) for'a 100.0 year storm
User specified values are as follows:
TC = 16.05 mm. Rain intensity = 3.23(In/Hr)
Total area = 72.820(Ac.) Total runoff = 163.030(CFS)
+++++++++++++++++++++.+++++.++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 7000.000 to Point/Station 7007.000
CONFLUENCE OF MAIN STREAMS ****
22
The following data inside Main Stream is listed:
In Main Stream number: 2
Stream flow area = 72.820 (Ac.)
Runoff from this stream = 163.030(CFS)
Time of concentration = 16.05 mm.
Rainfall intensity = 3.229(In/Hr)
Program is now starting with Main Stream No. 3
+++++++++++++++.++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 8003.000 to Point/Station 7007.000
USER DEFINED FLOW INFORMATION AT A POINT
User specified 'C' value of 0.900 given for subarea
Rainfall intensity (I) = 5.688(In/Hr) for a 100.0 year storm
User specified values are as follows:
TC = 6.67 mm. Rain intensity. = 5.69(In/Hr).
Total area = 2.450(Ac.) Total runoff = 13.200(CFS)
Process from Point/Station 8003.000 to Point/Station 7007.000 r CONFLUENCE OF MAIN STREAMS ****
The following data inside Main Stream is listed:
In Main Stream number: 3
Stream flow area = 2.450 (Ac.)
Runoff from this stream = 13.200(CFS)
Time of concentration = 6.67 mm.
Rainfall intensity = 5.688(In/Hr)
Suiranary of stream data:
Stream Flow rate TC Rainfall Intensity
No. (CFS) (rain) (In/Hr)
1 729.591 35.83 1.923
2 163.030 16.05 3.229
3 13.200 6.67 5.688
Qmax(1) =
1.000 * 1.000 * 729.591) +
0.596 * 1.000 * 163.030) +
0.338 * 1.000 * 13.200) + = 831.169
Qmax(2) =
1.000 * 0.448 * 729.591) +
1.000 * 1.000 * 163.030) +
0.568 * 1.000 * 13.200) + = 497.314
Qma.x(3) =
1.000 * 0.186 * 729.591) +
1.000 * 0.416 * 163.030) +
1.000 * 1.000 * 13.200) + = 216.759
Total of 3 main streams to confluence:
23
Flow rates before confluence point:
729.591 163.030 13.200
Maximum flow rates at confluence using above data:
831.169 497.314 216.759
-Area of streams before confluence:
714.050 72.820 2.450
Results of confluence:
Total flow rate = 831.169(CFS)
Time of concentration = 35.833 mm.
Effective stream area after confluence = 789.320 (Ac.)____
ofcomputations,) (total _study_aréá) (7189 .320) ((Ac.
This is the area into the upper end of Reach W4. The total area
tributary to Reach W4 is 789.32 acres plus the tributary area
downstream of El Camino Real, which was delineated from the
topographic mapping on the Study Area Exhibit and is 22.70 acres.
24
DRAINAGE AREA EXHIBIT FROM CHANG CONSULTANTS' LOMR
;
1 -.
vfsT : •,; - .•. . I ' ;,-•___
- S ' I
- 7
-
1 I.;
- -
— ;
•
BCI
- -
BC2 -
BC3 -
BASIN AH3
BJB C3 - AHI
- ' BASIN 1 BC4
(RRCH) BJ C4 • ..
----- AH2
1 RR2 I
-
RCA
DSAH AH9 AH7 -
A 10 ARADAY
AH4
LBASIN AH6 MELROSEI
.-•- BASIN 1 - '.. .• - -
Legend
AH8 AH5 - - •i *
" HEC-1WORKMAP
-. .- WITH USGS TOPOGRAPHIC MAP
Major Watersheds - S - - : 12-8-04
Drainage Basins
7 I "I fltontnn Bas ns
1' 5:.
APPENDIX B
SCCWRP FIELD SCREENING DATA
Chapter 5. Open Channels
Table 5-13 Maximum Permissible Velocities for Lined and Unlined Channels
Material or Lining Maximum Permissible
Average Velocity* (ftlsec)
Natural and improved Unlined Channels
FineSand, Colloidal ............................................................................... ..................................... 1.50
SandyLoam, Noncoiloidal ..........................................................................................................1.75
SiltLoam, Noncollóidal ........................................................................... ..................................... 2.00
Alluvial Silts, Noncolloidal ...........................................................................................................2.00
OrdinaryFirm Loam ......................................................... ........................................................... 2.50
VolcanicAsh ..............................................................................................................................2.50
Stiff Clay, Very Colloidal ............................................................................................................... 3.75
Alluvial Silts, Collodal ..................................... ............................................................................ 3.75
ShalesAnd Hardpans ........... ...................................................................................................... 6.00
FineGravel .................................................................................................................................. 2.50
Graded Loam To Cobbles When Noncolloidal ...........................................................................3.75
Gwded Silts To Cobbles When Colloidal .................................................................................... 4.00
Coarse Gravel, .Noricolloidal............................4.00
Colbies And Shingles.. - -- - (5 oà
SandySilt ...................................................................................................................................2.00
SillyClay ..................................................................................................................................... 2.50
Clay.............................................................................................................................................6.00
PoorSedimentary Rock ....................................................................... ........ -.............................. 10.0
Fully-Lined Channels
Unréinfórced Vegetation.................................................- ........................................Si)
ReinforcedTurf ..........................................................................................................................10.0
LooseRiprap ................................................................................................................per Table 5-2
GroutedRiprap ...........................................................................................................................25.0
Gabions......................................................................................................................................15.0
SoilCement ................................................................................................................................15.0
Concrete.....................................................................................................................................35.0
Maximum peimissible velocity listed hem Is basic guideline; higher design velocities may be used, provided appropriate
technical documentatloi from manufacturer.
Son Diego County Drainage Design Manual Page 5-43
July 2005
Form 3 Support Materials
Form 3 Checklists I and 2, along with information recording in Form 3 Table I,
are intended to support the decisions pathways illustrated in
Form 3 Overall Vertical Rating for Intermediate/Transitional Bed.
Form 3 Checklist 1: Armoring Potential
A A mix of coarse gravels and cobbles that are tightly packed with <5%
surface material of diameter <2 mm
X B Intermediate to A and C or hardpan of unknown resistance, spatial extent
(longitudinal and depth), or unknown armoring potential due to surface
veneer covering gravel or coarser layer encountered with probe
C Gravels/cobbles that are loosely packed or >25% surface material of
diameter <2 mm
Form 3 Figure 2. Armoring potential photographic supplement for assessing intermediate beds
(16 < d50 < 128 mm) to be used in conjunction with Form 3 Checklist I.
(Sheet 2 of 4)
RESULT FOR ALL STUDY REACHES
Form 3 Checklist 2: Grade Control
X A Grade control is present with spacing <50 m or 2/Sw m
No evidence of failure/ineffectiveness, e.g., no headcutting (>30 cm), no
active mass wasting (analyst cannot say grade control sufficient if mass-
wasting checklist indicates presence of bank failure), no exposed bridge
pilings, no culverts/structures undermined
Hard points in serviceable condition at decadal time scale, e.g., no apparent
undermining, flanking, failing grout
If geologic grade control, rock should be resistant igneous and/or
metamorphic; For sedimentary/hardpan to be classified as grade control', it
should be of demonstrable strength as indicated by field testing such as
hammer test/borings and/or inspected by appropriate stakeholder
B Intermediate to A and C - artificial or geologic grade control present but
spaced 2/Sv m to 4/Sv m or potential evidence of failure or hardpan of
uncertain resistance
o C Grade control absent, spaced >100 m or >4/Sw m, or clear evidence
of ineffectiveness
Form 3 Figure 3. Grade-control (condition) photographic supplement for assessing intermediate
beds (16 < d50 < 128 mm) to be used in conjunction with Form 3 Checklist 2.
(Sheet 3 of 4)
RESULT FOR ALL STUDY REACHES
FORM 4: LATERAL SUSCEPTIBILTY FIELD SHEET
Circle appropriate nodes/pathway for proposed site
OR use sequence of questions provided in Form 5.
(Sheet I of I)
RESULT FOR ALL STUDY REACHES
B - 10
FORM 6: PROBABILITY OF MASS WASTING BANK FAILURE
If mass wasting is not currently extensive and the banks are moderately- to well-consolidated, measure
bank height and angle at several locations (i.e., at least three locations that capture the range of
conditions present in the study reach) to estimate representative values for the reach. Use Form 6 Figure
1 below to determine if risk of bank failure is >10% and complete Form 6 Table 1. Support your results
with photographs that include a protractor/rod/tape/person for scale.
Bank Angle Bank Height Corresponding Bank Height for Bank Failure Risk
(degrees) (m) 10% Risk of Mass Wasting (m) (<10% Risk)
(from Field) (from Field) (from Form 6 Figure 1 below) (>10% Risk)
Left Bank 2 m --- <10%
Right Bank ---- 2 m --- <10%
.an hjli! Jfl)
30 7.6
35 4.7
40 33
45 2.1
50 1.5
55 Li
60 0.85
65 0.66
70 0.52
80 0.34
90 0.24
O Stable 10% Risk —50% Risk 90% Risk X Unstable
4 x
30
0
X
X x
X
E
0
\.x x
00 2 (P O\.X x
0000
M CO 00 0. X..
0 00 0
oco 00 0 00
30 40 50 60 70 80 90
Bank Angle (degrees)
Form 6 Figure 1. Probability Mass Wasting diagram, Bank Angle:Heightl% Risk table, and
Band Height:Angle schematic.
(Sheet I of 1)
RESULT FOR ALL STUDY REACHES
B - 12
Map Details
esult View CRITICAL STRESS CALCULATOR RESULTS FOR REACH El
Define Drainage Basins Basin: Agua Hedionda Watershed Project: Ranch Costera & El Camino Real Wdenin
Li U LPOC
Vlanage Your Point of Compliance (POC)
.nalyze the receiving water at the 'Point of Compliance' by completing
his form. Click Edit and enter the appropriate fields, then click the
Jpdate button to calculate the critical flow and low-flow threshold
:ondition Finally, click Save to commit the changes
Cancel Save Update
Channel Susceptibility: ..OW
Low Flow Threshold: 10.5Q2
Channel Assessed: IYes Vertical Susceptibility: Low (Vertical) V I
Watershed Area (ac): 10.24 Lateral Susceptibility: Low (Lateral)
Material: jVegetation
Roughness: 10.100
Channel Top Width (ft): 1100.0
Channel Bottom Width (ft): 120.0
Channel Height (ft): [5.0
Channel Slope: 10.02891 x
c
1 -'
c4 ,, ,-
H
Map Details
Result View CRITICAL STRESS CALCULATOR RESULTS FOR REACH E2
Define Drainage Basins Basin Agua Hedionda Watershed Project. Ranch Costera & El Camino Real Wideninc
_J Li LI LPOC
Manage Your Point of Compliance (POC)
Analyze the receiving water at the Point of Compliance by completing
this form. Click Edit and enter the appropriate fields, then click the
Update button to calculate the critical flow and low-flow threshold
condition. Finally, click Save to commit the changes.
Cancel Save Update
Channel Susceptibility: iLOW
Low Flow Threshold: 0.5Q2
Channel Assessed: JYes
Watershed Area (ac): 10.0731
Material: jVegetation H
Roughness: 10.100
Channel Top Width (ft): 175.0
Channel Bottom Width (ft): 15.0
Channel Height (ft): 110.0
Channel Slope: 1005511 x
Vertical Susceptibility: J Low (Vertical)
Lateral Susceptibility: }Low (Lateral)
Lrce
--
.. - •- :: •"
1'If
Map Details
esuit View CRITICAL STRESS CALCULATOR RESULTS FOR REACH E3
Define Drainage Basins Bastn Agua Hedionda Watershed Project: Ranch Costera & El Camino Real Wideninc
-F777 _F77 711- LPOCJ
Manage Your Point of Compliance (POC)
Analyze the receiving water at the Point of Compliance by completing
this form. Click Edit and enter the appropriate fields, then click the
Update button to calculate the critical flow and low-flow threshold
condition. Finally, click Save to commit the changes.
Cancel Save Update
Channel Susceptibility: ILOW
Low Flow Threshold: 10.502
Channel Assessed: Yes V1 Vertical Susceptibility: ILow (Vertical)
Watershed Area (ac): 10.0732 Lateral Susceptibility: Low (Lateral)
Material: lVegetation
Roughness: 10.100
Channel Top Width (ft): 145.0
Channel Bottom Width (ft): 15.0
Channel Height (ft): 110.0
Channel Slope: 10.036 x
Map Details
esult View CRITICAL STRESS CALCULATOR RESULTS FOR REACH E4
Define Drainage Basins iasin Agua Hedionda Watershed Projec' Ranch Costera & El Camino Real Wideninç
LI L °c
Manage Your Point of Compliance (POC)
Analyze the receiving water at the 'Point of Compliance' by completing
this form. Click Edit and enter the appropriate fields, then click the
Update button to calculate the critical flow and low-flow threshold
condition. Finally, click Save to commit the changes.
Cancel aie • tI
Channel Susceptibility: ..OW
Low Flow Threshold: O.502
Channel Assessed: IYes 17/1
Watershed Area (ac): 0.1272
Material: lVegetation
Roughness: 10100
Channel Top Width (ft): 150.0
Channel Bottom Width (ft): 28.0
Channel Height (ft): 15.0
Channel Slop.: 10i247
Vertical Susceptibility: Low (Vertical)
Lateral Susceptibility: j Low (Lateral)
Large Ve.
Map Details
esult View CRITICAL STRESS CALCULATOR RESULTS FOR REACH E5
, Define Drainage Basins En Agua Hedionda Watershed Poi(—' Ranch Costera & El Camino Real Widenini
J-77 U Li LPOCT
Manage Your Point of Compliance (POC)
Analyze the receiving water at the Point of Compliance by completing
this form. Click Edit and enter the appropriate fields, then click the
Update button to calculate the critical flow and low-flow threshold
condition. Finally, click Save to commit the changes.
Cancel Save Update
Channel Susceptibility: ILOW
Low Flow Threshold: 0"5Q2
Channel Assessed: Yes
Watershed Area (ac): 10.3963
Material: lVegetation
Roughness: 10.100
Channel Top Width (ft): Fio
Channel Bottom Width (ft): 136.0
Channel Height (ft): 15.0
Channel Slope: jo.00921 x
Vertical Susceptibility: J Low (Vertical) -11
Lateral Susceptibility: Low (Lateral) VI
Map Details
esult View CRITICAL STRESS CALCULATOR RESULTS FOR REACH E6
Define Drainage Basins En Agua Hedionda Watershed Project: Ranch Costera & El Camino Real Wideninc
Li Li LPOC
Manage Your Point of Compliance (POC)
nalyze the receiving water at the Point of Compliance' by completing
his form. Click Edit and enter the appropriate fields, then click the
Jpdate button to calculate the critical flow and ow-flow threshold
:ondition. Finally, click Save to commit the changes.
Cancel 11 Save 1 Update
Channel Susceptibility: LOW
Low Flow Threshold: 10.5Q2
Channel Assessed: IYes Vertical Susceptibility: J Low (Vertical)
Watershed Area (ac): 10.39641 x Lateral Susceptibility: J Low (Lateral)
Lalije
Material: lVegetation
Roughness: 10.100
Channel Top Width (ft): 1270.0
Channel Bottom Width (ft): 115.0
Channel Height (ft): 4.0
Channel Slope: io.0088
r,'
I I t• —
Map Details
esult View CRITICAL STRESS CALCULATOR RESULTS FOR REACH E7
Define Drainage Basins Agua Hedionda Watershed P'cy:t Ranch Costera & El Camino Real Wideninc
_f777 7 IF POC
Manage Your Point of Compliance (POC)
Analyze the receiving water at the Point of Compliance' by completing
this form. Click Edit and enter the appropriate fields, then click the
Update button to calculate the critical flow and low-flow threshold
condition. Finally, click Save to commit the changes.
Cancel Save Update 1
Channel Susceptibility: ILOW
Low Flow Threshold: 10.5Q2
Channel Assessed: 1yes Vertical Susceptibility Low (Vertical)
Watershed Area (ac): 14.680 Lateral Susceptibility Low (Lateral)
Material: jVegetation
Roughness: 10.100
Channel Top Width (ft): 1220.0
Channel Bottom Width (ft): 156.0
Channel Height (ft): 14.0
Channel Slope: 10.0061 x
Map Details
esult View CRITICAL STRESS CALCULATOR RESULTS FOR REACH E8
Define Drainage Basins En Agua Hedionda Watershed Project Ranch Costera & El Camino Real Wldenlrn
H U II
Manage Your Point of Compliance (POC)
Analyze the receiving water at the 'Point of Compliance' by completing
this form. Click Edit and enter the appropriate fields, then click the
I Update button to calculate the critical flow and low-flow threshold
condition. Finally, click Save to commit the changes
ICancel L Save IuPd!!j
Channel Susceptibility: ILOW
Low Flow Threshold: 0.5Q2
Channel Assessed: Yes Vertical Susceptibility: Low (Vertical)
Watershed Area (ac): 15.1101 x Lateral Susceptibility: J Low (Lateral)
Larce Ve'
Material: IVegetation
Roughness: 0.100
Channel Top Width (ft): 1500.0
Channel Bottom Width (It): 185.0
Channel Height (It): 12.0
Channel Slope: 10.0091
Map Details
tesult View CRITICAL STRESS CALCULATOR RESULTS FOR REACH WI
, Define Drainage Basins Esiv Agua Hedionda Watershed Project Ranch Costera & El Camino Real Widening
Li Li LPOC
Manage Your Point of Compliance (POC)
Analyze the receiving water at the 'Point of Compliance by completing
this form. Click Edit and enter the appropriate fields, then click the
Update button to calculate the critical flow and low-flow threshold
condition Finally, click Save to commit the changes.
1k'L lr
Channel Susceptibility: i.ow
Low Flow Threshold: 0.5Q2
Channel Assessed: IYes V I Vertical Susceptibility: Low (Vertical)VI
Watershed Area (ac): 0.0054 Lateral Susceptibility: Low (Lateral)
Material: lVegetation
Roughness: 0.100
Channel Top Width (It): 180.0
Channel Bottom Width (It): [ii
Channel Height (It): 14.0
Channel Slope: 10.0448
r S
Map Details
esuIt View CRITICAL STRESS CALCULATOR RESULTS FOR REACH W2
Define Drainage Basins sin Agua Hedionda Watershed Project Ranch Costera & El Camino Real Wldenin(
Li LI LPOC
Manage Your Point of Compliance (POC)
Analyze the receiving water at the 'Point of Compliance' by completing
this form. Click Edit and enter the appropriate fields, then click the
Update button to calculate the critical flaw and law-flow threshold
condition. Finally, click Save to commit the changes.
I,,,.Cancel Save Update
Channel Susceptibility: LOW
Low Flow Threshold: 11.5Q2
Channel Assessed: Yes
Watershed Area (ac): 10.8078
Material: lVegetation
Roughness: [o —,(—)0
Channel Top Width (ft): 1280.0
Channel Bottom Width (ft): 120.0
Channel Height (ft): 14.0
Channel Slope: 10.01911 x
Vertical Susceptibility: Low (Vertical)
Lateral Susceptibility: Low (Lateral)
L roe 'I•
Map Details
esult View CRITICAL STRESS CALCULATOR RESULTS FOR REACH W3
Define Drainage Basins basin. Agua Hedionda Watershed Protect Ranch Costera & El Camino Real Widenin
Li LI L P°c J I______________________________
Manage Your Point of Compliance (POC)
Analyze the receiving water at the 'Point of Compliance' by completing
this form. Click Edit and enter the appropriate fields, then click the
Update button to calculate the critical flow and low-flow threshold
condition. Finally, click Save to commit the changes.
Cancel Save Update
Channel Susceptibility: LOW
Low Flow Threshold: 10.5Q2
Channel Assessed: Yes Vertical Susceptibility: j Low (Vertical)
Watershed Area (ac): 1.1157 Lateral Susceptibility: Low (Lateral)
'A. 4 .'• -.
: .' :
Material: jVegetation
Roughness: 10.1oo
Channel Top Width (ft): 1150.0
Channel Bottom Width (ft): 58.0
Channel Height (ft): 2.0
Channel Slope: 10.0127
1"N
1rr.
Map Details Details
Result View CRITICAL STRESS CALCULATOR RESULTS FOR REACH W4
Define Drainage Basins ',_,'sin Agua Hedionda Watershed Protect: Ranch Costera & El Camino Real Wideninc
LI Li LPOC
Manage Your Point of Compliance (POC)
Analyze the receiving water at the Point of Compliance by completing
this form. Click Edit and enter the appropriate fields, then click the
Update button to calculate the critical flow and low-flow threshold
condition. Finally, click Save to commit the changes.
Icance1 Save I Update
Channel Susceptibility: LOW
Low Flow Threshold: 10.502
Channel Assessed: Yes Vertical Susceptibility: ILow (Vertical) V1
I
Watershed Area (ac): 11.2688 Lateral Susceptibility: Low (Lateral) Vi
Material: lVegetation
Roughness: 1Oi0O
Channel Top Width (ft): 170.0
Channel Bottom Width (ft): 116.0
Channel Height (ft): 14.0
Channel Slope: 10.018