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HomeMy WebLinkAboutPIP 05-25x1A; HCP Bressi Ranch PA 2; Planned Industrial Permit (PIP) (3)HYDROMODIFICATION SCREENING FOR BRESSI RANCH PLANNING AREA 2 April 6,2012 RECEIVED APR 2 7 2012 CITY OF CARLSBAD PUNNING DIVISION Wayne W. Chang, MS, PE 46548 ciiaiig(B(nMinMig Civil Engineering <• Hydrology»Hydraulics ° Sedimentation P.O. Box 9496 Rancho Santa Fe, CA 92067 (858) 692-0760 FOR REVIEW ONLY -TABLE OF CONTENTS - Introduction 1 Domain of Analysis 3 Initial Desktop Analysis 5 Field Screening 6 Conclusion 10 Figures 11 Normal Depth Analysis 22 APPENDICES A. SCCWRP Initial Desktop Analysis B. SCCWRP Field Screening Data MAP POCKET Study Area Exhibit As-Built Reference Drawings Bressi Ranch Drainage Map FOR REVIEW ONLY INTRODUCTION The City of Carlsbad's January 14, 2011, Standard Urban Storm Water Management Plan (SUSMP) outlines low flow thresholds for hydromodification analyses. The thresholds are based on a percentage of the pre-project 2-year flow (Q2), i.e., O.IQ2 (low), O.3Q2 (medium), or O.5Q2 (high). A threshold of O.IQ2 represents a downstream receiving conveyance system with a high susceptibility to erosion. This is the default value used for hydromodification analyses and will result in the most conservative (greatest) on-site facility sizing. A threshold of O.3Q2 or O.5Q2 represents downstream receiving conveyance systems with a medium or low susceptibility to erosion, respectively. In order to qualify for a medium or low susceptibility threshold, a project must perform a channel screening analysis based on a "hydromodification screening tool" procedure developed by the Southem Califomia Coastal Water Research Project (SCCWRP). The SCCWRP results are compared with the critical shear stress calculator results from the County of San Diego's BMP Sizing Calculator to establish the appropriate susceptibility threshold of low, medium, or high. aTY OF OCEANSlOE OTY OF ENQNITAS NOT TO SCALE This report provides hydromodification screening analyses for the Bressi Ranch Planning Area 2 project being designed by Fuscoe Engineering, which is located between El Camino Real, Gateway Road, Alicante Road, and Town Garden Road in the city of Carlsbad (see the Vicinity Map above and the Study Area Exhibit in the map pocket). The site is within Planning Area 2/Lot 2 of the overall Bressi Ranch project (CT 00-06). The site covers 23.1 acres and has been mass-graded with gently sloping pads in accordance with Drawing No. 400-8A (all referenced drawings are in the map pocket). The site is currently undeveloped except for a series of temporary desilting basins around the southerly and easterly site perimeters. There is no significant off-site runoff onto the site. Surface runoff on the mass-graded site generally flows in a southerly direction. The runoff is ultimately collected by one of two storm drain systems that convey runoff southerly away from the site. The westerly system (sheets 4 and 5 of Drawing No. 400-8C) is located near the southwest comer of the site, crosses Town Garden Road, and discharges through a 42-inch RCP with D-41 energy dissipater into a natural canyon immediately south of the site. This is the westerly point of compliance for hydromodification. The outflow from this energy dissipater enters Reach 1 (see the Study Area Exhibit in the Map Pocket). Hydromodification screening analyses require the overall study area to be subdivided into reaches (this is described in more detail in the next section). Reach 1 is a natural drainage course that flows in a southerly direction for over 440 feet to the easterly point of compliance, which is described next. The easterly storm drain system (sheets 15 and 16 of Drawing No. 400-8C) is near the southeast comer of the site, continues south over 700 feet within Alicante Road, and discharges through a 60-inch RCP with D-41 energy dissipater to a regional detention basin west of Alicante Road. The detention basin then discharges west into the aforementioned natural canyon through parallel 24- and 30-inch RCP's connected to a D-41 energy dissipater. This is the easterly point of compliance for hydromodification. The easterly point of compliance is at the downstream end of Reach 1 and the upstream end of Reach 2 (see the Study Area Exhibit). Runoff in the natural canyon flows overland in a southerly direction towards Alga Norte Community Park. The upper 1,088 feet of the natural canyon is within Reach 2, while the lower 763 feet is within Reach 3. The existing earthen berm that crosses the natural canyon is the boundary between Reach 2 and 3. The canyon mnoff is ultimately collected by a 72-inch RCP at the north end of the park (sheets 20 and 21 of Drawing No. 419-2B), which corresponds to the south end of Reach 3. This storm drain conveys the runoff over 1,500 feet south to a discharge point beyond Poinsettia Lane. The SCCWRP screening tool requires both office and field work to establish the vertical and lateral susceptibility of a downstream receiving channel to erosion. The vertical and lateral assessments are performed independently of each other although the lateral results can be affected by the vertical rating. A screening analysis was performed to assess the low flow threshold for the easterly and westerly points of compliance. The initial step in performing the SCCWRP screening analysis is to establish the domain of analysis and the study reaches within the domain. This is followed by office and field components of the screening tool along with the associated analyses and results. The following sections cover these procedures in sequence. DOMAIN OF ANALYSIS SCCWRP defines an upstream and downstream domain of analysis, which establish the study limits. The County of San Diego's HMP specifies the downstream domain of analysis based on the SCCWRP criteria. The HMP indicates that the downstream domain is the first point where one of these is reached: • at least one reach downstream of the first grade control point • tidal backwater/lentic waterbody • equal order tributary • accumulation of 50 percent drainage area for stream systems or 100 percent drainage area for urban conveyance systems (storm drains, hardened channels, etc.) The upstream limit is defined as: • proceed upstream for 20 channel top widths or to the first grade control point, whichever comes first. Identify hard points that can check headward migration and evidence of active headcutting. SCCWRP defines the maximum spatial unit, or reach (a reach is circa 20 channel widths), for assigning a susceptibility rating within the domain of analysis to be 200 meters (656 feet). If the domain of analysis is greater than 200 meters, the study area should be subdivided into smaller reaches of less than 200 meters for analysis. Most of the units in the HMP's SCCWRP analysis are metric. Metric units are used in this report only where given so in the HMP. Otherwise English units are used. Downstream Domain of Analvsis The downstream domain of analysis for the study area has been determined by assessing and comparing the four bullet items above. The project runoff will discharge into the natural canyon at the easterly and westerly points of compliance (POC). The downstream domain of analysis will be below these POCs. Per the first bullet item, the first permanent grade control below the discharge location is at 72- inch RCP at the north end of Alga Norte Community Park. Since the storm drain containing this RCP continues for over a thousand feet south, one reach (656 feet) downstream of the grade control will be within a non-erodible pipe. Therefore, the downstream domain of analysis based on the first bullet item will be the grade control created by the 72-inch RCP entrance. The second bullet item is the tidal backwater or lentic (still) waterbody location. The nearest tidal backwater or lentic waterbody is Batiquitos Lagoon, which is over 2 miles south of the POCs. The final two bullet items are related to the tributary drainage area. According to Project Design Consultants' February 2003, Drainage Report, Bressi Ranch Mass Grading & Backbone Improvements, the areas tributary to the easterly and westerly POCs are 149.1 and 23.1 acres, respectively (the proposed project will generally maintain these drainage areas). The equal order tributary is the point below the easterly and westerly POCs with the same drainage area as the POCs. For the easterly POC, the equal order tributary will be beyond Alga Norte Community Park. For the westerly POC, the equal order tributary will be within the natural canyon. Since the natural canyon is not a stream system or urban conveyance system, the fourth bullet point does not apply. Based on the above information, the 72-inch RCP was selected as the downstream domain of analysis point for both POCs. The downstream domain of analysis for the westerly POC could have been selected as the point in the natural canyon with a tributary area of 23.1 acres, but since the easterly POC analysis point is at the 72-inch RCP, this was chosen for the westerly POC as well. Per the first bullet item, the downstream domain of analysis begins one reach below the 72- inch RCP grade control. As discussed above, a reach is not to exceed 200 meters (656 feet). Since the storm drain system containing this RCP continues for over a thousand feet, one reach downstream of the grade control will be within a non-erodible pipe. Therefore, the downstream domain of analysis based on the first bullet item will be the grade control created at the 72-inch RCP entrance. Upstream Domain of Analvsis The area upstream of the RCP outlet of each POC is an existing graded 2:1 fill slope with landscaping. The only storm runoff on the slope is from direct precipitation. Consequently, the slope is not anticipated to erode (erosion was not observed during a recent site visit) and the upstream domain of analysis for both POCs will be at each RCP outlet, i.e., the 42-inch RCP outlet and its D-41 establishes the upstream domain of analysis for the westerly POC, and the 24/30-inch RCP outlets and their D-41 establish the upstream domain of analysis for the easterly POC. Study Reaches within Domain of Analvsis The entire domain of analysis extends from each of the POCs to the 72-inch RCP at the north end of Alga Norte Community Park. The total domain of analysis covers approximately 2,300 feet. The domain of analysis was subdivided into three study reaches with similar characteristics (see the Study Area Exhibit). Reach 1 (upper reach) extends from the westerly POC to the easterly POC. Reach 2 (middle reach) continues from the easterly POC downstream to a large existing berm crossing the lower third of the natural canyon. The berm is earthen and the center portion was breached sometime in the past. The canyon runoff currently flows through the breach. Reach 3 (lower reach) extends from the earthen berm to the 72-inch RCP. Each reach is longer than the 656 feet maximum reach length specified by SCCWRP. Review of topographic mapping, aerial photographs, and field conditions reveals that the physical (channel geometry and longitudinal slope), vegetative, hydraulic, and soil conditions within each reach are relatively uniform. Subdividing the reaches into smaller subreaches of less than 656 feet will not yield significantly varying results within a reach. Although the screening tool was applied across the entire length of each of the three reaches, the results will be similar for shorter subreaches within each reach. INITIAL DESKTOP ANALYSIS After the domain of analysis is established, SCCWRP requires an "initial desktop analysis" that involves office work. The initial desktop analysis establishes the watershed area, mean annual precipitation, valley slope, and valley width. These terms are defined in Form 1, which is included in Appendix A. SCCWRP recommends the use of National Elevation Data (NED) to determine the watershed area, valley slope, and valley width. The NED data is similar to USGS mapping, so it is not very detailed. For this report, 2-foot contour interval mapping from the City of Carlsbad's GIS department was used to establish the valley slope and valley width in the natural canyon because they are more accurate than NED. The Study Area Exhibit contains this mapping combined with PDC's drainage map. The watershed area tributary to the reaches was established from PDC's Febmary 2003 drainage report and the City's 2-foot contour interval topographic mapping (see the Study Area Exhibit). PDC's drainage report indicates that the tributary area at the downstream end of Reach 1 is 186 acres. An additional 21.48 acres is tributary to Reach 2. This was delineated from the City's topographic mapping and a site visit. The topographic mapping does not reflect the existing El Camino Real Corporate Center southeast of the intersection of El Camino Real and Town Garden Road, so this area was confirmed from as-built plans and a site visit. Finally, an additional 10.20 acres is tributary to Reach 3 based on the topographic mapping. Based on this information, the drainage areas at the downstream end of Reaches 1, 2, and 3 are 186, 207, and 218 acres (0.29, 0.32, and 0.34 square miles), respectively. The mean annual precipitation was obtained from the County of San Diego's BMP Sizing Calculator and is 13.3 inches (see Appendix A). The valley slope of Reaches 1, 2, and 3 was determined from the City's 2-foot contour interval topographic mapping. The valley slope is the longitudinal slope of the channel bed along the flow line, so it is determined by dividing the elevation difference within a reach by the flow path. The valley width is the bottom width of the creek channel. The average valley width within each reach was estimated from the topographic mapping, field observations, and review of aerial photographs. The valley slope and valley width at each reach are summarized in Table 1. m Reach Valley Slope, m/m Valley Width, m m 1 0.0360 8 2 0.0313 12 3 0.0160 15 Table 1, Summary of Valley Slope and Valley Width These values were input to a spreadsheet to calculate the simulated peak flow, screening index, and valley width index outlined in Form 1. The input data and results are tabulated in Appendix A. This completes the initial desktop analysis. FIELD SCREENING After the initial desktop analysis is done, 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., dso < 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 retum divergent values, the most conservative value shall be selected as the flow threshold for the hydromodification analyses. Visual observation reveals that each study reach contains a densely vegetated canyon (see the figures following the report text). The vegetative density extends relatively uniformly across the canyon bottom and sides. Due to the vegetative cover, D-41 concrete energy dissipaters at each POC, and relatively small canyon flows (the SCCWRP 10-year flow from Form 1 in Appendix A is at most 52 cubic feet per second), the vertical and lateral stability was anticipated to have a limited susceptibility to erosion. 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 18. The first step is to assess the channel bed resistance. There are three categories defined as follows: 1. Labile Bed - sand-dominated bed, little resistant substrate. 2. Transitional/Intermediate Bed - bed typically characterized by gravel/small cobble. Intermediate level of resistance of the substrate and uncertain potential for armoring. 3. 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 show photographs of the channel in the study reaches. The vegetative cover along and adjacent to the flowline of each reach was so dense that they were either difficult to access or not possible to access at all unless the vegetation was trimmed. A gravelometer is included in some photographs to show the dense vegetative cover on portions of the ground surface. Each square on the gravelometer indicates grain size in millimeters (the gravelometer squares range from 2 to 180 millimeters). The figures show dense vegetation throughout Reaches 1 through 3. The vegetation consists of a variety of mature grasses, shmbs, and trees. Vegetation prevents bed incision because its root structure binds soil and because the aboveground vegetative growth will reduce fiow velocities. Table 5-13 from the County of San Diego's Drainage Design Manual outlines maximum permissible velocities for various channel linings (Table 5-13 is included 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 begin is likely greater than 5 fps in most of the natural canyon 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 canyon has an equivalent grain size of at least 64 mm. Vegetation in a watercourse can be dynamic, i.e., the vegetation size and density can change over time. An increase in vegetation will further reduce the potential for vertical incision, while a decrease can allow greater incision. A primary cause for a reduction in vegetation is removal due to hydraulic forces and shear stress during periods of high flow. Since the natural canyon is not subject to high flow (SCCWRP-defined 10-year flow rate is at most 52 cfs), the flow volumes and velocities will have minimal impact on the vegetative condition in the reaches. A normal depth analysis was performed, which determined that the flow velocity under 52 cfs is 2 fps (the analysis is attached after the figures). Furthermore, a sign posted in Alga Norte Community Park indicates that the natural canyon is a preserve, so vegetation should not be subject to human removal. Based on the photographs and site investigation, the bed resistance is within the transitional/intermediate bed category. Dr. Eric Stein from SCCWRP, who co-authored the Hydromodification Screening Tool in the Final Hydromodification Management Plan (HMP), indicated that a transitional/intermediate bed requires the most rigorous analysis steps and will generate appropriate results for the size range. 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: 1. Armoring potential ~ three states (Checklist 1), this checklist determines the amount of gravel and cobbles within a natural channel. Gravel and cobbles resist erosion and armor a channel. Therefore, an increase in the amount and density of gravel and cobbles indicates less potential for erosion. 2. Grade control - three states (Checklist 2), this checklist determines if there are manmade or natural grade control features in a natural channel. A grade control will prevent a channel from degrading and eroding by maintaining the channel bed at a fixed elevation. The spacing of grade controls is considered because more closely-spaced grade controls are more effective at preventing erosion. 3. Proximity to regionally-calibrated incision/braiding threshold (Mobility Index Threshold - Probability Diagram), this diagram determines the potential for channel bed incision. The potential increases as the flow rate and channel slope increase. The potential also increases with smaller bed material. The flow rate, channel slope, and average grain size are considered in the 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 three 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. Due to the dense vegetative growth, the armoring potential could have been rated higher, 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, each reach contains dense vegetation (see the figures). The plant roots and fallen tree tmnks serve as a natural grade control. The spacing of these is much closer than the 50 meters identified in 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, each reach is within Category A on Checklist 2. The Mobility 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 dso as well as the Screening Index determined in the initial desktop analysis (see Appendix A), dso is derived from field conditions. As discussed above, the equivalent grain size for the densely vegetated canyon in the field is at least 64 mm. The Mobility Index Threshold diagram shows that the 50 percent probability of incising or braiding for a dso of 64 mm has an index of 0.101 (in red rectangle on diagram). The Screening Index for each reach calculated in Appendix A varies from 0.0194 to 0.0408. Since the Screening Index values for each reach is less than the 50 percent value, each reach falls well 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 is based on these values and the equation: Vertical Rating = [(armoring x grade control)''^ x screening index score]'^'^ = [(6x3)''^x3]''^ = 3.6 Since the vertical rating is less than 4.5, each reach has a low threshold for vertical susceptibility. Lateral Stability The purpose of the lateral decision tree (Figure 6-5 from County of San Diego HMP included in Figure 19) 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 fiuvial 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 both 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 tightly-packed particles (see figures). 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 topographic mapping indicates that the maximum natural bank angle is 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 vertical rating is high, the braiding risk is considered to be greater than 50 percent. Excessive braiding can lead to lateral bank failure. For the Reaches 1, 2, and 3, 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 (red circles are included on the Form 4: Lateral Susceptibility Field Sheet decision tree in Appendix B showing the decision path). CONCLUSION The SCCWRP channel screening tools were used to assess the downstream channel susceptibility for the Bressi Ranch Planning Area 2 project. The project runoff will discharge into a natural canyon south of the site at an easterly and westerly point of compliance. Each POC contains RCP discharging through D-41 concrete energy dissipaters. The assessment was made for the natural canyon from the POCs to Alga Norte Community Park, which is just under 0.5 miles south of the site (domain of analysis). The assessment was performed based on office analyses and field work. The results indicate a low threshold for vertical and lateral susceptibilities. 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 Reach 1, 2, and 3. Based on these values, the critical stress results retumed a low threshold. 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 resuhs are consistent with the physical condition of the natural canyon within the domain of analysis, which is densely vegetated environmental preserve. None of the three study reaches nor D-41 outlets exhibit signs of extensive, ongoing erosion. 10 1 ] Figure 1. Looking Upstream Towards Reach 3 from Alga Norte Community Park I I Figure 2. Looking Laslerly Towards Middle of Reach 3 11 1 4 4 Figure 3. Looking Southerly Down Reach 3 Towards Alga Norte Community Park Figure 4. 72-Inch RCP at North End of Alga Norte Community Park (Downstream Study Limit) i 12 I I I I 1 % 4 Figure 5. Looking Downstream Towards Reach 3 from Earthen Berm Figure 6. Looking Upstream Towards Reach 2 from Earthen Berm 13 i I I I I I Figure 7. Looking Easterly Towards Middle of Reach 2 Figure 8. Looking Downstream Towards Reach 2 from Regional Detention Basin 14 I I I 5 ] 4 i Figure 9. D-41 Energy Dissipater at Easterly Point of Compliance Figure 10. Looking Upstream Towards Reach 1 from Easterly Point of Compliance 15 I J I I I I Figure 11. Looking Westerly Towards Middle of Reach 1 Figure 12. Looking Southerly Towards Reach 1 16 I I I I Figure 13. Looking Downstream Towards Reach 1 from Westerly Point of CompUance 1 Figure 14. D-41 Energy Dissipater at Westerly Point of Compliance 17 I "1 J ] Figure 15. Gravelometer on Dense Grass Cover in Reach 3 Figure 16. Gravelometer on Vegetative Cover in Reach 2 ] J i 4 Figure 17. Gravelometer on Vegetative Cover in Reach 1 «& 2 Interface 19 1 1 I I LABILE BED • Sanci-Oo«rinated • dso < 16 mm • % surface sand > 2S% « Looeely-packad I CHANNEL BED RESISTANCE | IIVTERMEPIATE BED > UodGratety-to totxefy- pack«cl cobfo\« I gravel > Hardpan of uncertain depth, -extent srodMlty COARSE.IARMORED BED • dso > 128 mm • Boulder / large cobble • Ughlly-packed • <S% sand • Continuous bedrock • Conbnuoua concrete EXAt^lNE RISK FACTORS • grade conlrol • armoring potential • proximity to incision ttvediold go to bed drodibUity checklists arxJ incision diagram check list Fil out SCCWRP sccurig criteria to OMermine if (he receiving ctiannel has s HIGH, MEDIUM, or LOW auscepiibiity HIQH T MEDIUM LOW ] F/gureW. SCCWRP Vertical SusctptibWiy Figure 18. SCCWRP Vertical Channel Susceptibility Matrix 1* 20 lew • Fui/ ariroied .1 t«)H)u» Mi* «»l)llZ«»Oi in OOOi CCrxHon • Ha Mdcnu ly diule (tKnutKin / avulBiatn « Fuly conltnea. imety cowweJKftoMiliiidu LAftKAUV *OJUST*fiL£-J I > VES <>,RC LATERAL \ AtWUBTMErfre > OCCURRING?/ VES 4 r*o None, ar hstmt anif Imtod lo tModa and conttitdont EXTENSIVE FLUVWL EROSION OR CHure CinCfF rOHM*T»ON T Figure 6-5. Lateral Channel Susceptilulity Figure 19. SCCWRP Lateral Channel Susceptibility Matrix 21 Worksheet for Channel Reach - Normal Depth m 1 Friction Method Manning Formula Solve For Normal Depth tm Input Data Roughness Coefficient 0.100 Channel Slope 0.01600 ft/ft Left Side Slope 3.50 ft/ft {H:V) wm Right Side Slope 3.50 ft/ft (H:V) mm Bottom Width 15.00 ft Discharge 52.00 ft% ^^^^^^^^^ Results \ IHHHHHHHHHHHHlHHHHHIHil^HHHHHHHHBMHHHMHl Normal Depth 1.34 ft m Flow Area 26.48 ft= Wetted Perimeter 24.78 ft Hydraulic Radius 1.07 ft Top Width 24.41 ft Critical Depth 0.68 ft Critical Slope 0.17508 ft/ft ^^^^^^^^ Velocity 1.96 ft/s «• Velocity Head 0.06 ft MB Specific Energy 1.40 ft Froude Number 0.33 Flow Type Subcritical -GVF Input Data -Downstream Depth 0.00 ft Length 0.00 ft Ml Number Of Steps 0 GVF Output Data Upstream Depth 0.00 ft Profile Description Profile Headless 0.00 ft Downstream Velocity Infinity ft/s Upstream Velocity Infinity ft/s Normal Depth 1.34 ft Critical Depth 0.68 ft Mi Channel Slope 0.01600 ft/ft 4i 4/6/2012 8:17:13 PM Bentley Systems, Inc. Haestad Methods ScflMMtoyDEhtof/laster V8i (SELECTseries 1) [08.11.01.03] 27 Siemens Company Drive Suite 200 W Watertown, CT 06795 USA •H-203-755-1666 Page lot 2 APPENDIX A SCCWRP INITIAL DESKTOP ANALYSIS FORM 1: INITIAL DESKTOP ANALYSIS Complete all shaded sections. IF required at multiple locations, circle one ofthe following site types: Applicant Site / Upstream Extent / Downstream Extent Location: Latitude: 33.1262 Longitude Natural -117.2641 Description (river name, crossing streets, etc.): yyestof AMcante Road, amd north of Alga Norte Community Park 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 1 Table 1. Initial desktop analysis in GIS. Symbol Variable Description and Source Value _ "> ^ <n •-<U 0) c <D Q. 01 CO P rt- ' w O; Q. C tu to CO Wv Area (mi') Contributing drainage area to screening location via published Hydrologic Unit Codes (HUCs) and/or < 30 m National Elevation Data (NED), USGS seamless server Mean annual Area-weighted annual precipitation via USGS delineated polygons using precipitation records from 1900 to 1960 (which was more significant in hydrologic (in) models than polygons delineated from shorter record lengths) Valley slope (m/m) Valley width (m) Valley slope at site via NED, measured over a relatively homogenous valley segment as dictated by hillslope configuration, tributary confluences, etc., over a distance of up to ~500 m or 10% ofthe main- channel length from site to drainage divide Valley bottom width at site between natural valley walls as dictated by clear breaks in hillslope on NED raster, irrespective of potential 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) See attached Form 1 table on next page for calculated values for each reach. Form 1 TabI e 2. Simplif ied peak flo 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 1 Table 1. m Symbol Dependent Variable Equation Required Units Value m Qiocfs Qio 10-yr peak flow (ft%) 10-yr peak flow (m^/s) Qiocfs= 18.2*A°^^*P°^^ Qio = 0.0283 * Qiocfs A (mi^) P(in) Qiocfs (ft^/s) See attached Form 1 table m INDEX Wref 10-yr screening index (m^^/s°^) Reference width (m) INDEX = Sv*Qio°^ Wref = 6.99 * Qio "''^ Sv (m/m) Qio (m^/s) Qio (m^/s) on next page for calculated values for each •m VWI Valley width index (m/m) VWI = Wv/Wref Wv(m) Wref (m) reach. m {Sheet 1 of 1) m B-3 I i • i 1 J 1 i 1 i i i 11 t I I i I I If t I 11 11 SCCWRP FORM 1 ANALYSES Reach Upper (Reach 1) Middle (Reach 2) Lower (Reach 3) Area A, sq. mi. 0.29 0.32 0.34 Mean Annual Precip. P, inches 13.3 13.3 13.3 Valley Slope Sv, m/m 0.0360 0.0313 0.0160 Valley Width Wv, m 8 12 15 10-Year Flow QlOcfs, cfs 46 50 52 10-Year Fiow QIO, cms 1.3 1.4 1.5 Reach Upper (Reach 1) Middle (Reach 2) Lower (Reach 3) 10-Year Screening Index INDEX 0.0408 0.0373 0.0194 Reference Width Wref, m 7.81 8.14 8.30 Valley Width Index VWI, m/m 1.02 1.47 1.81 Note: The areas were obtained from the watershed delineations shown on the Study Area Exhibit. The mean annual precipitation was obtained from the County of San Diego's BMP Calculator (see Appendix A). The valley slope was determined from the elevations and flow lengths from the Study Area Exhibit. The valley width was estimated from the topographic mapping on the Study Area Exhibit and a site investigation. The 10-year flow, screening index, reference width, and valley width index are calculated from the equations on Form 1 (see Appendix A). Result View Define Drainage Basins Basin BressI Ranch Drainage Area Project Bressi Ranch Planning Area 2 IT Basin 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. Name Bressi Ranch Drainage /Vea Description: |Bressi Ranch PA 2 Design Goal: Treatment + Flow Control Rainfall Basin: Oceanside Point of Compliance: |Natural Canyon Outfalls Project Basin Area (ac): 23.10 Mean Annual Precipition (in): 13. MEAN ANNUAL PRECIPITATION FROM COUNTY BMP CALCULATOR APPENDIX B SCCWRP FIELD SCREENING DATA : Chapter 5. Open Channels : : : m : - il Table 5-13 Maximum Permissible Velocities for Lined and Unlined Channels Material or Lining Maximum Permissible Average Velocity* (ft/sec) Natural and Improved Unlined Channels Fine Sand, Colloidal 1.50 Sandy Loam, Noncolloidal 1.75 Silt Loam, Noncolloidal 2.00 Alluvial Silts, Noncolloidal 2.00 Ordinary Firm Loam 2.50 Volcanic Ash 2.50 SUff Clay, Very Colloidal 3.75 Alluvial Silts, Collodal 3.75 Shales And Hardpans 6.00 Fine Gravel 2.50 Graded Loam To Cobbles When Noncolloidal 3.75 Giaded Sills To Cobbles Wliwii Colloidal 4.00 Coarse Gravel, Noncolloidal 4.00 Cobbles And Shingles 5.00 Sandy Silt 2.00 Silty Clay 2.50 Clay 6.00 Poor Sedimentary Rock 10.0 Fully-Lined Channels ^^^^^^^^^^^^^^^ Unreinforced Vegetation 5.0 Reinforced Turf 10.0 Loose Riprap per Table 5-2 Grouted Riprap 25.0 Gabions 15.0 Soil Cement 15.0 Concrete 35.0 • Maximum pem^lssible velocity listed here Is basic guideline, higher design velocities may be used, provided appmpriaie technical documentatioi from manufacturer I m San Diego County Drainage Design Manual Page 5-43 July 2005 3 I Form 3 Support Materials Form 3 Checklists 1 and 2, along with information recording in Form 3 Table 1, are intended to support the decisions pathways illustrated in Form 3 Overall Vertical Rating for Intermediate/Transitional Bed. ] I 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 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 ARMORING POTENTIAL most resistant least resistant I iPBanoa B; (Jto = lOO mm, 4 incMT, looser, or > 25% sand oniole; djc = 23 mm, i%sand I Form 3 Figure 2. Armoring potential photographic supplement for assessing intermediate beds (16 < dso < 128 mm) to be used in conjunction with Form 3 Checklist 1. (Sheet 2 of 4) B-7 I I I I Form 3 Checklist 2: Grade Control Grade control is present with spacing <50 m or 2/Sv 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. undermining, flanking, failing grout no apparent • 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 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 Grade control absent, spaced >100 m or >4/S„ of ineffectiveness m, or clear evidence I 4 4 rado Canyon: grouted ripr some undermining at road CTO Form 3 Figure 3. Grade-control (condition) photographic supplement for assessing intermediate beds (16 < dso < 128 mm) to be used in conjunction with Form 3 Checklist 2. (Sheet 3 of 4) I B-8 I Note: the equivalent d50 in each reach taking dense vegetation into account is 64 mm. The Screening Index Values from the spreadsheet In Appendix A (0.0194 to 0.0408) for each reach are less than the 50% Risk values for 64 mm (0.101), so the risk of incising Is less than 50%. Regionally-Calibrated Screening Index Threshold for Incising/Braiding For transitional bed channels (dso between 16 and 128 mm) or labile beds (channel not incised past critical bank height), use Form 3 Figure 3 to determine Screening Index Score and complete Form 3 Table 1. ] \ 4 4t ^ 1 1 0.01 0.001 ^ > 0.1 Stable 10% risk dso (mm) •: Braided — 50% risk 10 100 Incising 90% risk GIS-derived: 1 0-yr flow & valley slope Field-derived: djo (100-pebble count) Model Type dso (mm) 50% Risk (m^s/so-*) 128 0.145 ression mm 98 80 0.125 0.114 1 64 0.101 o 1 O) o 48 0.087 o 1 O) o 32 0.070 16 0.049 8 0.031 at E « c D: ^ 4 0.026 o <o to w 2 0.022 •5) o .3 1 0.018 •5) o .3 0.5 0.015 Form 3 Figure 4. Probability of incising/braiding based on logistic regression of Screening Index and dso to be used in conjunction with Form 3 Table 1. Form 3 Table 1. Values for Screening Index Threshold (probability of incising/braiding) to be used in conjunction with Form 3 Figure 4 (above) to complete Form 3 Overall Vertical Rating for Intermediate/Transitional Bed (below).. Screening Index Score: A = <50% probability of incision for current Qio, valley slope, and dso; B = Hardpan/dso indeterminate; and C = >50% probability of incising/braiding for current Qio, valley slope, and dso. dso (mm) From Form 2 S/Qio° ' (m^-^"-') From Form 1 C *n ".5 /_.1.5i_0.5. Sv Qio (m Is ) 50% risk of incising/braiding from table in Form 3 Figure 3 above Screening Index Score (A, B, C) Overall Vertical Rating for Intermediate/Transitional Bed Calculate the overall Vertical Rating for Transitional Bed channels using the formula below. Numeric values for responses to Form 3 Checklists and Table 1 as follows: A = 3, B = 6, C = 9. Vertical Rating — ^[{^Jarmoring * grade control) » screening index score} Vertical Susceptibility based on Vertical Rating: <4.5 = LOW; 4.5 to 7 = MEDIUM; and >7 = HIGH. (Sheet 4 of 4) B-9 I FORM 4: LATERAL SUSCEPTIBILTY FIELD SHEET Circle appropriate nodes/pathway for proposed site OR use sequence of questions provided in Form 5. * 4 4 LATERALLY ADJUSTABLE? —^"""^ yes LOW •Fully armored / bedrock bank stabilization in good condition •No evidence of chute formation avulsions •Fully con t 4 (Sheet 1 of 1) 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 (degrees) (m) 10% Risk of Mass Wasting (m) (from Field) (from Field) (from Form 6 Figure 1 below) Bank Failure Risk (<10% Risk) (>10% Risk) Left Bank Right Bank probability of mass wasting in moderately/well consolidated banks O Stable 10% Risk 50% Risk 90% Risk X Unstable 4 \ 0 N 1 0 ^ 1 0 CP* 9 0 00 O^O^ ft. V Ox \ X \ 0 cN. X X X X X X » \ 0 N 1 0 ^ 1 0 CP* 9 0 00 O^O^ ft. 0 V ^ \ 0 1 X \ 0 cN. «x x'^ X V \ 0 N 1 0 ^ 1 0 CP* 9 0 00 O^O^ ft. 0 1 w ^^^^ 1 I '" 1 Oo I 1 30 7.6 35 4.7 40 37 45 2.1 50 1.5 55 1.1 60 0.85 65 0.66 70 0.52 80 0.34 90 0.24 50 60 70 Bank Angle (degrees) Bank height and angle schematic il : Form 6 Figure 1. Probability Mass Wasting diagram, Bank Angle:Height/% Risk table, and Band Height:Angle schematic. Probability is less than 10% for the existing bank angles (2:1 = 26.6 degrees) in Reach 1, 2, and 3. (Sheet 1 of1) B-12 5^ uKnow - Wfhdiows TntenBSTK I^^V^^^^H^ brwncald.com'was!evuaterr'MapOL.»px Favorites \ 'iS f . uKncw : OCBisnowARC AKC MqppingStn Oiego S - 0 • LJ!) # * P»9«'' Safety* Tools" Brown • • > Caldwell UKnOW San oiego BMP sizing Calculator Home Contacts Legal [Enter address - street, city... LeeatiM Raingsuge Piir^ Contoun Manage Basins San Diego Count/ • HMP Manage Map Layers 3i Rjin Oauge; Mem Annual Rainf jll Q] R'ln Basins 01 Soil Typ* S^ectaTool Toolkit HydroMod Tools Toot: BMin Mwtagw Map data provided t>y Op*nStreetfjtap Map Detail* Define Drainage Basins Basin Basin 2 Proiect Bressi Ranch Planning Area 2 U LT Manage Your Point of Compliance (POC) Analyze ttie receivina water at ttie Point of Compliance' Dy completing this lorm. CllcK Edit and enter me approprtate fields, ttien dick ttie Update outton to calculate ttie critical flow and low-flow tiireshold condition. Finally. clicK Save to commit the changes. Cancel I Save • Update Channel Susceptibttty: |LOW Low Flow Thresliold: 0.5O2 Channel Assessed; Yei Watershed Area (ac): |l88.00 Vertical SusceptibUily: Low (Vertical) Lateral SusceptitiHity: Low (Lateral) Material: Vegetation Roughness: 0.100 Channel Top Width (Kf. 25 0 Channel Bottom Width (It): 10.0 Channel Helgnt (It): 5.0 Channel Slope: 0.036 Done Trusted sitps | Protected Mode Off % 100% CRITICAL STRESS CALCULATOR RESULTS FOR REACH 1 ^ J » . fc.... ..A fc. Ik. -M Ik. M ..Jt tk^.jt ifc^^ IL a Ifc S / u<now - Window. Internrf|^^JJ|||||^||j^j|^^^ •J. J» Hi V ^.^11^^^''^ 'I'- n ow.brwncald.com " i *' 1 1'- Favoritts | ^ uKnow Swc OCB is now ARC ARC Mapping San Diego ;@uKnow Pag«» Safety Tools' Brown' ^Caldwell uKno VJiJt;li1iiiriiir*a»uliiK^riiitiK#;Utiiihi01iIia;Kt>] Enter address - street, cSy... Location PaingaDfie Rain Contours Map Osta provided by OpfoStre^lMap Map DetaHt Manage Basins View Jl^lllllllll^llllll^^ i San Diego Courtv- HMP 1 Define Drainage Basins Basin Basin 4 Project Bressi Ranch Planning Area 2 Manage Map Lay ers Z' Rain Oaii^vs Mean Annual Rainfall O Rain Ba5ir)s ' 'ID Soli Type Select a Tool Toolkm Hydrol.'cd Too* Tool: BoM Manager Manage Your Point ot Compliance (POC) Analyze the receiving water at the 'Point of Compliance" by completing this form. Click Edit and enter the appropriate flelds. then cttck the Update button to calculate the cntical flow and low-ftow threshold condition. Finally. dicK Save to commit the changes. Cancel • Sane • Update Channel Susceptmmty: |LOW Low Flov/ Threshold: 0.502 Channel Assessed: Yes Watershed Area (ac): 209.00 Vertical Susceptlt>lllty: Low (Vertlcsl) Lateral Susceptibility: Low (Lateral) Matenal: Vegetatton Roughness: 0.100 Channel Top Width (H): Uo.O Channel Bottom Width (It): |15,0 Channel Heighl (It): 5,0 Channel Slope: 0.031 Dene If' @ Intemet) Protected Mode: Off CRITICAL STRESS CALCULATOR RESULTS FOR REACH 2 T3 * M00% • ik. A Ik.. • Windows !ntemrt'6qpfe«r^ /Favorites >; uKnow Sic OCB is now ARC ARC Mapping San Oiego ^ uKnow ?i ^ B ' lis «» » Pag*' Safety Tools-' BrownCaldwell uKnOW Gan Dicgo BMP siting Calculatoi , ..... -BrownCaldwell uKnOW Gan Dicgo BMP siting Calculatoi , 'Enter address - streel city. . LocaliM Raingaug& Ram ConXsuii Manage Basins 3 San tHeso Court.;. HKIP Manage Map Layers Ram Oauges .^1 u«an Annual R .ainljll jJ Rain Dasina Soil Typ* Toolkit: rtydrowod Tooh Toob Basin tJartager ti^ap data provided dy OrM?iiSw.?*t!v^ap Map D*tallt Result View Define Drainage Basins Basin Basin - Combined UG Storage Areas Proiect Bressi Ranch Planning Area 2 Manage Your Point of Compliance (POC) Analyze the receiving water at the Point of Compliance' by completing this form. CHcy. Edit and enterthe appropriate fields, then dici'. the Update button to calculate ttie critical flow and tow-llow threshold condition. Finally, click Save to commit the changes. Cancel • Save • Upilule. Channel Susceptibility: COW Low Flow Threshold: 0.502 Channel Assessed: Yes Watershed Area (ac): 219.00 Vertical SusceptibWty: Low (Vertical) Lateral SusceptRMtty: Low (Lateral) Material: Vegetation Roughness: jO-100 Channel Top Width (It): 50.0 Cliannel Bottom Width (ft): 15.0 Channel Height (ft): 5.0 Channel Slope: 0.016 9' GS '/ Tiutttd site', I Protected Mode Off CRITICAL STRESS CALCULATOR RESULTS FOR REACH 3 I • M00% - MASS GRADING AND EROSION CONTROL PLANS: BRESSI RANCH SOURCE OF TOPOORAPHY KPOaurm sHOm OH mrsr PIMIS WS etmuTco moroanMurwi ucmoos rmu fraaiAtm CMIMEWD CM. mr ». tax sM-io />mii suims rawiufMr sHom HBSOM coHFcRKs nnumm. «<v> MXUKAer STmDMDS. MPORTANT NOTICE sccim 4ite/4m or DC imoimon cooe Koims A ae /tan BcmncAWt mmni sr ISSUB> acras A "Ptrnt m ncaKtir au K ma fOR nx/f uc ttm is. Muuem CAU UMOKIIOIM) seffxe ALtfi: im rm t-toa-vi 4iss: no MMXNC O^IS BCFOK mi aa. EARIHWORK cur: iTnoooct ntKom.- v>a,aiocr. mFCKT/tmxr: oer. PEFBRENCE DRAVmaS: cmsSAO a naitsmtr rrmsnm we rnmrniAL SACxaat miotoiems wxxntuL eACKSOMC mpnomam a CAimomL owe m Ji»-s tns m-3 om. m 3ts-s otK. na too-te AND mtf-ar me. m »7-tj * xr-K sua M> Mo-as tm. m MO-a one m m-te 'DECLARATION OF HESPONSBLE CHARGE' I HERtBY OeCLARC THAT I AU THC £W»KR OT KORIf FOH IMS PKOJCCT, THAT I HAVC txeKasto REsnHSBLt CHAKcc oval mc oesat or we PKOJCCT AS DCTIHCD « sccnoM tnu or THC aoswrss AHO PROfESSows cooc AND THAT THE cesai a coNSSTtNT mm euRRENr STANOAROS. I UNOCRSTAND THAT INE CMFOi m PKOJCCT MAMMSS AHO SPCOFKAVONS SV PC OTY or CAnssAO DOCS MOT mmve UL AS EMOWEW OF HORK, OF ur RCSPONSIBIUTKS roe PMJECT oesKiH. nrni: mxjecT DCSICN cewstuMwrs 701 a siBtrr. si»ir goo BB^ HMAF: AOOSESS-. ore. SMTT: SAM CCCft CAUFORMA lafPWOWE- (et3) 2JS-S47I LOCAim }ii4cr II.:- concRCK n A sttMDtm sumtr mi o» PL. fl rauwo gfat _ <io«B««K KSQtumH no. mem Mtuec CROiORr u. smaos 42351 WORKTOBEDONB tc tMKMoeir warn SMJU COHSBT or vt OONSIKUCKM crAacuisuo FUS. KOfBIAL tKAOK. DRMMIX FAOUTfS, tWBWI COKITO. MOUTIES AMD PRTPARAim or AS-eULI PLAMS. AS-BUIT CtOLOBC HAPS AHO KPORTS. AUASSHOmCK KOUKCB OM THS SCTV lUMS AMO OTY StAMOAmS. SFfOnCADOKi KCOMKMOIIS, HCSOLVXMS AHD OHOUAMCCS OTW OH MST FIAMS Mr MWtBCKT atiK swiu K HUFoaieD K ACCORDAMCC mm wtFouomc oocuMCHTs, ameiTAT nrncor coHsmcTioH. ASORecieo BY VX OTY CMOHBX. I CMtssw MMOPw. coor ; ory or CW9M0 STANPMDS } THB SCT or PLAMS 4 KSOUnOB Ma SiOI. SXX S104. SX5. Slot. Si07. 51011 SlOi BATwturv, ma. 5 THC STAMBARO SPeOfKAlUHS FOR PUBUC HORKS OONSnuCIKN (CROM BOOIQ I. PC SOLS TsroRT (n£o "siPPiDsmAL etomatKAi mcsDamoN FOR MASS aUOHSt BRCSa RAMCM. CARISBAO, CA'PRCPARCB BY IBOHTOH AMO ASSOOAICS BAIB) MARCH 14. iOM. 7. mc SAM ooo ARCA RCaOMAl STAHOARO ORAmcS AMD AS MAY BC MOOm BY mt OTY OF CmSBAB STAHDA/BS, OOCUUBtT MO. 7133X1. a omaifMTM. APPROYAI OOOMMTS OAIEP IV>V*> SOLS ENtaiNEBrS CBrmCATB CMOHecR or pc STATE OF CAUFOKHK PRHOPAUY OOUC BUSIMFSS W ne FBO OF APPIB) SOI. MCCHAMK& HtROY Canrt THAT A SAMPUMC Am snar or THC SOI OOMUKMS PRaum mm iHesfWus "ABC tYMCCR irnOCR wr MtCnCN BCnmCM THC DAKS ar • ~f99 r*t=- AMD , nwftloouPLCirCOPKSor THC sots KPORf COmjCO FROM MS SHOT. •INlVI'IKCOiaCWMnMSl HAS am sa^^TOT^oF^^ Tit an OUSMCT. LEQBQr I7£V SYlKOOt HM—a AKA KOtMn - rmsnw owisur fMSNEP OOmoUR — FHSItB SPOT BIV. CVTAOPC- WWAM DAM OLSOM P CC HO: DATE /- r- »3 tJCCMSC CXHRAmM BAIC: . LEQAL DE5C»F7TO(V PARCB. V OF tOOMDARY ABJUSTUaT S4S, OOajUCHT MO l3>»-Xti7S} nr W THC OFFKC or SAH BfCO COUMTY BCCOROCR. FtB 11. 1999. PROJECT LOCA-nON TMS PROJCCT IS LOCAKD WMV ASStSSMS PARCa HUHBOIfi) 113-030-17 t Hf-ipo-a mr CAUFORNIA COCROmATC IHOa or THIS PROtCT IS: 1390-6251 AAMBCRT COOROnAmS Jat-tCT6) —iirT« SHCCT 31 . -saiSDD-40- SCTTUHBIT UOMnORHC STAnOMS PCR SOIS ABVRT 9 mil trORMTIOM (FUST AUCRICAM nrLO sec SHCCT 32 (7) HOTB AU STAMDMD DRAmO MDMtCRS RBTR V SAM OteO ARtA PtOOHAL STAMOARB DRAmeS OMLCSS OTHCRmSC HXATIB. 'OTY or CARLSBAD SUPPiOBITAL STANDARD DRAHHC - TOIPORARY OCSITAIKH SASm amCT AMB CAPAOTY TABLC OWNBi/DEVELOPBR HAMC: WRIAR BRCSSI YOinm. UC ACORCSS: STBO FUtI STRaT SUUC 310 CARLSBAD. CA. tlOOB PHOHC: (TSO) W«-W»S OWhERS CERTIHCAm IHAT A RCeiSTCRCB SOIS CMOta OR CCOLOOST HAS (EZM OR milC OtlR-AU CRAOMC ACTIVTY AMD ADVSC ON PC COUPACKN AHD tic IN SHCCT I SHErri . SNEOS 3-31 SWnS 32 swris Jl SHBTTS 34-S2... UIU SWrt KCYUAP AMD MOTES NOIB * PCTUS MASS ORAOMC PLAMS siKtr (ROSS sccnoMs .,ilKlS«M {anROLKTAtS ca/moLFUns s/z/oa PiiomcjDBSKSiCoNsajiMm ncGIS-mAnOH e/CWATtOH OAlt. 07/f5/03 OATS. /-Lt.^ TB— not wm caisS!lxmi cMAtut fc iwgw Ti.>ijBM4<»43lahUI^ SI PLANNING DEPARTMENT APPROVAL r Houa a HoiMtn. PLMMM DUKcnw (SOCO) KOiMicweD BY; CHa«'W»«-v>g!<rMt»»4 (WtWTIIAIIE) i^^Kfc t it ft /». 7/. n. IS. M. IS. n. i*. «i /Jt tl.ttt%t4.X». tTLf. X». »ft »ir^ 1«t»«, B7, 3«. 3J. 4-L4-1. *3L gfflLitriendr/ov ctuute n SHUT REVI90N DESCRIPTION DATE IwmAt oiNQiAmayni OTYiimgWC 'AS BUO-CONSTRUCTION CH, ANCEA' 'AS BUILr JB&tf_ St«ET 1 QTY OF CARLSBAD EilONUJBMB BEPAIOIKMT SHETIS 62 MASS GRAONO AND EROWM CONIROL PLAHS FOR: CT oo-oe N01E sen APPftOVcO: LLOKO 6. HU8BS,^»^ CHKD BY;. WV«P BY:- PROJCCT NO. CT 00-06 ' DBAWMG HO. I 4O0-8A 032205 IKIOJ II22^» 080204 011405 •••J CHDOrd«d Ot/W/SOOJ (!5.'5a.SJ PS: I 1% UbaimMi§«kliAmdYHiilblliMUi-m OF TMC MTUIAL CAS TRAiemSKM mat. m>PomROpaiAiacaapmiTSMAu.teAium»»mt-mr cr MfY PORBOM OF wt MAnjRtt OAS TKAimiaOM PftUML ownme NO. 400-BA ) o % • o eg atAPHKAL SCAU PiiomctpEsaNCaH^ T—I m«>n«,sii»im SaOiwiCAnni *tLil-uir wrWAi. OFBIM REVISION OESCmiON M,! .rjyi'?<F?rr?wi MASt CMHW nANI nft~ MKSSf MNCN vm BY.- JH. 2241.01! J o O nsaw JT AW W MS iMHt eoMMcm It ma WBFY ueABon * BimtoM. comer nmmYrucABDM OR ami H N'- or fc mmMi «5 IMSMBM) Amnc MP met oMBWia CMWH mm. m memmm t-nr or un PORBCK cr Tit MATURM. »s mimsaaM nnmc f hi* I-i" • y 'f (UtAPmAL SCAIS Pi»XBcd)m3NCaNKLwra laaDii«>.CA «l« utmtm FAX tiuMaso Tan 'AS BUILr rnaa cagi |.i,|:|.'...'..".'l|.,J'..'..'!i| 9MCCT 15 qry OF CARLSBAD HAM OUDMi MM Mk~ a«S»;iMNCN OMLSBMA tMUnNMH APflWVmUXM) i. MUBBS^J'^ wan 62 MMdEerNO. CT 00-06 DRAWNO MO. 't^4« i > 0 20 40 80 GRAPHICAL SCALE f>£}lf1€0 Bl: REMSION DESCRIPnON Olid «P™CV«. OTY «WIOV«. CITY OF CARLSBAD pwwEEwwo oePAimiofr MASS ORAONS PLAMS FOR! BUeSS RAMCH CARLSBAD. CAUfOmA SHUTS 62 •j'PROvEO; uora B. XU^SMy CHKD BY:. BV»08Y. PROJECT NO. CT 00-06 CRAWNC MO- 400-BA •1 02103 ! fl1t4lis3 I I CITY OF CARLSBAD tUqtCEWNO 0€F*RT>ICNT SHrtTS 62 iPPROitC: LLO'rO 8 HU9SS 0)*AWNG NO. ^E:r.of-^e^44\M*ss-o«I^^•'•»»_gr^wr^^^^4^-G(^D^o«wo ci/fle/joc3 woosi PM PST J 071003 M o 00 O PLANS FOR THt lUPROVOCNT OF: BRESSI RANOH FEaOSm^ TOWN QAflDBi FtOAD SrOffU DRAH C*l*^S 13~3T-fa PROJECT NO. CT 00-06 DRAWNG NO 400-ac 071003 o -(^ •* O o 00 O Jot) no. 2244 00 occHTmrn PROFILE: STORM Cmff^ STA m+OO • 40' VCDt f-< PVC i ec irW 270.B2 '•r'^e'KP - 392! LF 0 II.OOX ! Oo > ctsi v» * tji; i)» +4-- 032205 "':'x^.<i3S!>-mM «i'«y/rj5o-o)t SO- RCP 11350-0)11 66ycFTi3x-o)-tf/ eo'if/sooq-Dtt/. so RCP(20C(>~I)}r 24 KP(IS50-e) 24'IKPI:3X-D) 24' HCPQJSO-Ot 24 IICP (20(X>-D1 T 24 /KPtlOOO-PI t 30- fO'tUX-OifM so gCP IISSO-D) tH 30 CUP l4Ct te HCPiiKo-o) IB' RCP (-1350-0) IB'RCP (1350-11) IB- Iia-(I350:^ 071003 wAmnem jomjs ADOt COVCH OkfS flfmrOROVC STW. (ffOD. (15') AOOl COlfS 0»fS RPHrCHONC Sim. itfOS, (2.0') toot COVfB 0«"» RBHF0ROHG SIHl SfOB fli"; AOOl. covrs oiri! Rfiwosovc sm sfoB. fio') «• IfNCIHS SClEtfD 5- BOIH ENDS PRIVATE CONTRACT BENCH MARK DCSCItlPVON: WASS^BS* IN COHCTftT W A ST/Mlim SWVrr Jtll. 0« w cfnrEKunc or n CAVWO gfAt ' loCADoiK, eouin' CF SAAT orco BCNCHHAIIK OFSKKAIKW WO. utaoo iit*imc aivAitoN: IHMT'U.SL MONEES Of KORK PPC if." AS-BiirLTS /se jK Rgtiseo Hocsos AHO YS REVISION DESCRIPTION OIHER APPROVAl OTY APraoVAl SHEET 15 "AS Buiur tiiTE atY OF CARLSBAD ENCWEERiNG OEPA.RTUENT SHEETS 27 PLANS FOR IHE IMPROVEI^IEXT Of; AiXMOE K>AD STOFU DHAJN APPROVED: LLOrD 8 MUSBS^/" E«>ff?CS 12-3'-t PROJECT NO. cr 00-06 ORAVIINC NO 400-8C U o o o I 00 O r \tngr\!!44\UASS-GRD\Slorir. Dr(!in\Res:-denli<ll\Res-SDI5 dwg aS/'tS/200S 04.0!. 14 PM PV •4- i 1 i- I ; -| -j i ' i .-;4.-.. HMO- tCuLtaM Itr Ra> - 525 LT O 2.00X Om • 2.2 ch r. I.e (ni" If n IB' biof IE OJl IB' i3B.74 otrr IS' 739.^0 IB' Kf ~ 312^ LF 9 tOt Qm X J.0 crs s.r tps t W IB' 239.07 I I t PCR SDRSD 0-41 L.i7y4-. , - TCP Of t-wm 230.00 pm OIK HO 400-8 MO- • ifl ^ PROFILE: STORM DRAIN ; i i AUCANTE ROAD STA. 102+97.44 SCALE noun. i'-4o' VESI. om MAW PiAiv mw SF; SF£Fr 1; i-i: 1/4 raw OASS PFHAP- v/tiL im FA^FHC unun TOOK (APPRCKD EOl/ALj ai 6- IHpf tJ/4--l I/J- twwrossiPAnK- P-4I IIA.IS PROFiJE- OPSV SPACE 1 STORMDRAIN SCALE: HORIZ l'-4ff KEPT I .illi 4--i- SrOfiW DRAIN DATA oaiA CR BHO RAon^cn. uNcin(nj H7l2f5}E 30' RO- (ijso-o; t / 34' RCP (1150-0) 1 / I wAimncHT jomrs I tool COYER OYER RCHrORdNO STEEL REOO (15') OPEN SPACE 1 SBE PLAN SHEET MO. 15 / 1/4 ION CLASS RIPRAP — r.zr W/n.l[R FABRIC WRtn 700* (APPROm EOUAL) OR 6' THICK J/4'-' 1/2' BASE LMT or I TON CROum RIPRAP T-4.3' r/TlLTER FABRIC WRAFI 700X fAPPROltP EOUK) OR «• MOT J/4"-1 1/2' BASE 1 ll EHWIONUENTAL LIMI IS 1/4 TDK ClASS RIPRAP I-2.7' W/TKIER FABRIC URAtl TOOx (APPROmi EOUAL) OR e' IHICK 3/4'-l 1/2' BASE PLAN OPEN SPACE 1 STORM DRAIN SCALE: I''40' 120 FOR PLAN VIEW SEE SHEET 15 PROJECTDESIGN CONSULTANTS •*J il Sntvx. Sojtt Sofi. Ssn IJkff. ( A 9: lOt fcl'lIl^M?! FAX ftl'J'UOW r \Crgr\!244\MASS-CflD\Slorm Drcin\f>esi(leniial\Res-SDI6<!»-g 0J./'9/MJ 01 JS 16 PU PS rNONEER Of WORK gj^a^ja? j^ReYBto HOLS Q's AHO vs REVISON DESCRIPTION PRIVATE CONTRACT T^SPEC?; OTHER APi^ROVAi b<it mrriAL C3TY APPROVIU. SMEET 16 "AS BUlur Rcz4VitS!— r»p3-V»r CITY OF CARLSBAD ENGINEERING DEPARtVENT SHEETS 27 PLANS FOR THE IMPROVEUENT CF; BRESSI RANCH RESDBmAL AUCANTE HOAD STOHU DfVM APPROVED UOYD B, HUBBS Ci*«t^ 12-31-05 OWN BY:£i CHKO BY;. RVWO BY: . PROXCT NO. CT 00-06 DRAWNG NO. 400-8C 032205 -«i o o • CO O onAWINOMJMBCfl DRAwma NUMScn DRAWWQ NUM8CR DRAWINO (*/ •BER • 41»-3B .20of2g LEGEND cinsv Msw rntr CAioi *AUN nn r (uoaneo) CATC» jwav rrff e CATot MSN rw c fDOi«jy C4IW «» rwr c riwtf; owovnr awocs Mt 34't2*' CONOKIt mXKS BOX 3 IKH J44 7 »-» 0 0-$ 0 0-8 @ ocMcnnr u« „ iff fg^a, i.if'art a f fCWHMtt MO mAtmO MNOMU MTT AMCW W SCH 40 nc PPf AS 9lOm CH PIAM 0 swarwwcuHEitr 50)30 SDMD Ih-tJ SHMN CHPIAH SMSD O-JB 50*50 D~tfO SCMS0»-/9M use* sr-1 • D C3 rpvea fpveie lar PKSD /VS-8UILT NOTE AI.»tlarFM«*«inicTCCMTMCTCAHt&UM«S. StQNinCANr CMANOIS WSM MAkt To APPftCVlb riAlrtWIKOVI'IMtMIMHAeFMCCOKAmtoVM. fife SMFcr C19 Wnmer Mr w Aw^ w Pfaa*. c^wiB »vw»i««o It K. MRtt DMMamMLlNC. CM. EDCWC EKING AM UM) SUnmK 7M CAUrOBNM OAKS OWI VISIA. CA IMI (760) 3N-«0]I <I) (TW) 5N-M4I (I) ffl 40 ao GRAPHIC SCAI,£ r« 40'-0' 3*4 W 2E 0*tt>MTWH "5;M! CITY OF CARLSBAD wjws rot: iiia~iWHI tatoMiff MW> < STORM DRAIN PLAN WILUAM t, n.WMC» /if -.^li—:.agigfei-= 4:»!s»«3_ OTY oonfiuer MO. 3*373 DRAwmaNUMBn ORAMmSNUMMR OnAIMNOMUMaEn 21 of 28 >t>i * • '^A,.4>T -. ® ® pccMCAcmu UNe rm CATCH r>#V F snow 0UW cuMteur - nnr A JOO /-\ — a SMSD O't 0->r D SERSD • a a • SCWSD 0-» • scffsa 0-9 dtco) « 9a SMOW ON PLAN TYPICAL SEI FRENCH DRAM NOrtS: ' STHFO fWfS; CMBiSlCN 0 TO BE flCREASCO 10 TAxE CARE cr tlCfCASCD »OIH CR iEHCIH OLE 10 SKE* CF uumc PIPES I KPS OF HEAOmXS. CH CRAOE CULaRTS, SIAU BE PLACED PARALLEL TO PRCfUE CRACC UNO* INf CRAOES ARE a OR MORE. J COKCREIt SHALL BE 560-C-32S0 »W A POOCH FIKISK < e/POSCO CORIIERS SHAU CHAHFEREO 3/4'. i nMmrpKESSwAu BE SET A i»sa«r Cf o/i mm A r Hmm. BETREEH O/tSOE DmCltP cr PMES fi» «=r nm MoMis SREAIER IMAH r use I ALIERNAIE OETAl-C MODIFIED WING TfPE HEADWALL WITH CHAINLINK FENCE Lw4u«f« A«iJiiiHtu« t f atirvaMUMtsI Ftusbg It c. MRa «MawwiaiNc. cim eiKMcawc MO UMO SUMVMO ru CMjroBMA OMS envt MSTA. CA MOai (7W) JM-M3I (1) (7(0) SM-S04I (I) ffl 40 20 0 GRAPHIC SCALE Aff-O" WTCJwnMLS CITY OF CARLSBAD jPJg*^ hut «* ui«"«ki( MiMiMiT MH usj wne- STORM DRAIN PLAN CIIY nmbCT MO. {TOMMMIA 3tSn fl 419.2» GRAPHIC SCALE 0 300 1 INCH = 300 FEET NOTE: TOPOGRAPHIC MAPPING SHOWN HEREON IS FROM CARLSBAD GIS DEPT. AND FROM PDC'S FEBRUARY 2003 BRESSI RANCH DRAINAGE REPORT (SEE INCLUDED PDC WORK MAP). STUDY AREA EXHIBIT