Loading...
HomeMy WebLinkAbout; HARMONY GROVE FIRE; PHASE I EROSION AND SEDIMENT CONTROL PLAN; 1997-03-14FINAL REPORT PHASE I EROSION AND SEDIMENT CONTROL PLAN FOR THE HARMONY GROVE FIRE CITY. OF, CARLSBAD, CALIFORNIA qt Engr.1Const. I go Ln VED City of Carlsbad ' 2075 Las Palmas Drive Carlsbad, CA 92009-1519 Woodward-Clyde Project No. 9651135F March 14, 1997 Woodward-Clyde Consultants Sunroad Plaza Ill, Suite 1000 1615 Murray Canyon Road San Diego, CA 92108 (619) 294-9400 Fax (619) 293-7920 FINAL REPORT PHASE I EROSION AND SEDIMENT CONTROL PLAN FOR THE HARMONY GROVE FIRE CITY OF CARLSBAD, CALIFORNIA Prepared for City of Carlsbad 2075 Las Palmas Drive• Carlsbad, CA 92009-1519 Woodward-Clyde Project No. 9651135F March 14, 1997 S 'T5TTh'ti i• - ,1I S Woodward-Clyde Consultants' S Sunroad Plaza III, Suite 1000 1615 Murray Canyon Road S San Diego, CA 92108 (619) 294-9400 Fax (619) 293-7920 Woodward-Clyde w Engineering & sciences applied to the earth & its environment March 14, 1997 Mr. Dick Cook City of Carlsbad 2075 Las Palmas Drive Carlsbad, California 92009-1519 SUBJECT: PHASE I SEDIMENT CONTROL PLAN FOR THE HARMONY GROVE FIRE CITY OF CARLSBAD, CA Woodward-Clyde Reference No. 965113 5F Dear Mr. Cook: Woodward-Clyde is pleased to. provide this final Phase I Erosion and Sediment Control Plan for the Harmony Grove Fire within the City of Carlsbad, California. This work was provided in accordance with our scope of work dated November, 1996. This final report incorporates the comments received from you and other City staff in February, 1997. Thank you for allowing us this opportunity to provide this report. If you require additional information of have any questions please give me a call at (619) 294-9400. Very truly yours, WOOD WARD-CLYDE CONSULTANTS Carol L. Forrest, P.E. Vice President I 7Y Woodward-Clyde Consultants • A subsidiary of Woodward-Clyde Group, Inc. Sunroad Plaza 3, Suite 1000• 1615 Murray Canyon Road • San Diego, California 92108 619-294-9400 • Fax 619-293-7920 TABLE OF CONTENTS Section1 Introduction ...................................................................................................................... 1-1 Section2 Background ................................................................................... . ................................... 2-1 Section 3 Early Action Measures .............. . ...... .............................................................................. 3-1 Section 4 Phase I Erosion and. Sediment Control Plan ................ . . . ................................................ 4-1 4.1 Identify Issues and Concerns (Step 1) ...................................................... 4-1 4.2 Develop Goals and Objectives (Step 2) ...................................................... 4-1 4.3 Perform the Erosion and Sediment Yield Study (Step 3) ........................4-2 4.3.1 Site Reconnaissance and Review of Available Information........4-2 4.3.2 Field Evaluation of the Harmony Grove Fire Area in Carlsbad........................................................................................4..3 4.3.3 Hydrology and Sediment Yield Analyses....................................4-4 4.3.4 Potential Mitigation Measure Locations......................................4-8 4.4 Develop Mitigation Measure Selection Criteria (Step 4).........................4-9 4.5 Nominate and Evaluate Alternatives (Step 5) ........................................ 4-10 4.6 Screen and Select Best Alternatives (Step 6) .......................................... 4-24 4.7 Develop Erosion and Sediment Control Plans and Specifications (Step 7) ........................................................... . ................. 4-26 .4.7.1 Location Map ............................................................................... 4-26 4.7.2 Details and Standard Specifications ........... . ................................. 4-26 4.8 Schedule and Implement the Plan (Step 8) ......... . .................................. 4-26 4.9 Operate and Monitor the Installed Systems (Step 9) .............................4-26 4.9.1 Storm Events ............................................................................... 4-27 Woodward-Clyde 0 . i List of Tables, Figures and Appendices Tables Table I Sediment Storage Capacity of Temporary Check Dams - San Marcos Creek Watershed ....... ............................................................................... 3-2 Table 2 Summary of Results from HEC-1 Flood Hydrograph Analysis ...........................4-5 Table 3 Sediment Yield Analyses, Flaxman Method - Pre-Burn Condition ..................4-7 Table 4 Sediment Yield Analyses, Flaxman Method - Post-Burn Condition.................4-7 Table 5 Erosion and Sediment Control Measure Alternatives ........................ . .. . ............. 4-Il Table 6 Selection of Preferred Alternatives .................................. . ................................. 4-25 Figures Figure 1 Study Area Map Figure 2 Watersheds and Concentration Points Figure 3 Locations of Preferred Mitigation Measures S Appendices S Appendix A HEC-1 Hydrology Study Appendix B Details and Standard Specifications Appendix C Site Visits to Localized Areas of Potential Problems odydo S W:9651135FEC01-D-R.DOC\13-Mar-97'9651135FSDG ii SECTIONONE Introduction This report presents a Phase I Erosion and Sediment Control Plan for the portion -of the City of Carlsbad that was affected by the October, 1996 Harmony Grove fire. This report presents specific recommendations for the control of erosion and sediment within the Carlsbad area at this time. The plan should not be applied to other areas or occurrences without modifications to account for changes in site conditions. - This Phase I plan addresses immediate actions that Woodward-Clyde Consultants (Woodward- Clyde) recommends be taken to reduce the potential adverse erosion and sedimentation effects due to this winter's rain storms. Later phases may include longer term recommendations to address issues that may arise in future years IOOthIIyIO 0 W:'9651135FEC01 -DA DOC\1O-Mar-97\9651135F\SDG 14. SECTIONTWO Background On Monday, October 21, 1996, the City of Carlsbad (City) and. adjacent areas including San Marcos, Olivenhain, Encinitas, and San Diego County unincorporated experienced a major firestorm that began in the Harmony Grove area. The fire burned for approximately twenty-four hours, fanned by Santa Ana winds from the east. The fire consumed over 8,600 acres of public and private land and destroyed more than 100 homes, including- 54 homes in Carlsbad. Many acres of vegetation were destroyed, leaving the slopes unprotected from the erosional effects of wind and rain. In November 1996, the City retained Woodward-Clyde to assess the hazards due to erosion and sedimentation resulting from the fire and to prepare a Phase I Erosion and Sediment Control Plan to address potential mitigation actions that could be taken to protect resources and improvements in the City. The objective of the Phase I Plan is to focus on the reduction of sediment transport from the denuded slopes through existing drainage courses to areas where the sediment could potentially impact public and private facilities or residences, as well as sensitive habitat and receiving water bodies, including Batiquitos Lagoon. Woodward-Clyde W:9651135F\EC01-0-R.D0C\14-Mar-97\9651 135F\SDG 21 SECTID NTHREE. Early Action Measures The first step in the emergency erosion and sediment control program is to provide immediate action items for the City to start implementing with City, NCCC, CDF Corrections, or other work force crews. The City employed NCCC and CDF Corrections labor crews to install approximately 144 burlap gravel-bag check dams in the small drainage tributaries that flow to Box Canyon and discharge through San Marcos Creek. Approximately 40 more check dams were constructed in tributaries and canyons draining to Encinitas Creek. The constructed check dams have a wide, solid base, relatively uniform weir section, and raised abutments. With only a few minor corrections, the check dams-have performed well in the first three winter storms, including a storm with a volume of more than 2.50 inches. Table 1 provides the sediment holding capacity of the gravel bag check dams constructed by the City, The total volume available to store sediment behind the check dams in the San Marcos Creek watershed is approximately 118,000 cubic feet. A more detailed assessment of the capacity of these measures relative to the anticipated increased sediment yield is provided in Section 4.3.3. In addition to the check dams, the detention basin adjacent to and upstream of the Arizona crossing (see Figure 1) was dredged to remove accumulated. sediment and restore capacity. Additionally, the previously blocked outlet pipe was re-opened, and a new riser was added on the upstream side. The volume available to store sediment upstream of the Arizona crossing is approximately 32,000 cubic feet. These immediate action items were reviewed in the field by Woodward-Clyde both before and after storms with Richard Cook of the City Engineering Department. Although Woodward-Clyde did not design or supervise the actual installation of the check dams or the restoration of the Arizona crossing detention basin, the installation of these measures were observed during field visits and are consistent with what would have been recommended and designed had we been involved in the Early Action Plan implementation immediately after the fire event. Woodward-Clyde W:9651135F\ECO1-D-R.DOC\14.Mar-97\9651135F'SDG 3-1 I LI SECTIONTHREE Early Action Measures Table 1 I SEDIMENT STORAGE CAPACITY OF TEMPORARY CHECK DAMS SAN MARCOS CREEK WATERSHED Check Dam Number Check Dam Dimensions (crest to invert x length x depth, in feet) Estimated Sediment Holding Capacity Behind Check Dam (ft) 1A 50x40x20 2,000 lB 5x30x15 1,125 1C 4x32x20 1,280 1D 54820 2,400 1E 3x20x15 450 iF 4x22x20 880 2A 02422 1,056 2B 4x30x22 1,320 2C 5x26x20 1,300 21) 4x26x24 1,248 2E 4x28x20 1,120 3A 02018 864 3B 02016 768 3C 4x24x16 768 4A 5x27x18 1,215 4B 4x28x20 1,120 4C 4x26x16 832 4D 02416 768 5A 5x20x16 800 SB 5x22x18 990 5C 4x22x18 792 SD 02020 960 6A 5x22x14 770 6B 5x22x18 990 6C 42016 768 60 42416 768 6E 02406 768 6F 4x28x18 1,008 7A 4x20x14 560 7B 5x22x16 880 7C 4x22x16 704 70 5x26x18 1,170 7E 42608 936 7F 4x26x20 2,080 8A 4x28x18 1,008 8B 4x30x22 1,320 9A 3x26x16 624 9B 4x30x18 1,080 9C 5x30x14 1,050 9D 5x30x12 900 9E 4x28x18 1,008 9F 4x20x24 960 10A 4x26x14 728 Woodward-Clyde W:9651135F\ECO1-D-R. DOW O-Mar-97\9651135FSDG 3-2 I SECTIONTHREE Early Action Measures Table 1 (Continued) SEDIMENT STORAGE CAPACITY OF TEMPORARY CHECK DAMS SAN MARCOS CREEK WATERSHED Check Dam Number Check Dam Dimensions (crest to invert x length x depth, in feet) Estimated Sediment Holding Capacity Behind Check Dam (ft') lOB 4x26x16 832 lOG 3x28x17 714 101) 4x26x20 1,040 IOE 5x30x16 1,200 10F 4x28x20 1,120 hA 3x18x12 324 lB 3x20x12 360 11C 3x20x14 420 liD 3x18x20 540 liE 02006 640 hF 3x21x17 535 hG 3x22x18 594 11H 02002 480 ill 02204 616 11J 5x36x22 1,980 ilK 3x38x26 1,482 ilL 4x36x20 1,440 11M 4x30x20 1,200 41N 5x24x20 1,200 110 02208 792 1P 4x22x19 836 11Q 5x22x18 990 12A 3x28x11 462 12B 3x38x10 570 12C 3x40x8 480 13A 3x28x10 420 13B 0304 480 13C 4x30x10 600 13D 4x30x10 500 13E 4x30x12 720 13F 3x26x12 468 13G 012600 2,520 14A 3x28x10 420 14B 4x30x10 600 14C 03002 720 140 3x26x12 468 14E 4x126x10 2,520 iSA 02802 672 15B 02606 832 15C 3x24x10 360 150 02808 1,008 16A 4x26x12 624 16B 02014 672 I Woodward.Clyde W9651135F'EC01-0-R.DOC1O-Mar-97\9651135F\SDG 33 I I Li I I I I LI I Li I I LI I 1 I I SECTIONTHREE Early Action Measures Table 1 (Continued) SEDIMENT STORAGE CAPACITY OF TEMPORARY CHECK DAMS SAN MARCOS CREEK WATERSHED Check Dam Number Check Dam Dimensions (crest to invert x length x depth, in feet) Estimated Sediment Holding Capacity Behind Check Dam (ft') 16C 3x80x10 1,200 17A 4x26x14 728 178 02012 576 17C 4x4x12 576 17D 4x26x10 520 18A 4x27x12 648 18B 02801 616 18C 02014 672 18D 4x29x16 928 19A 4x28x16 896 19B 4x32x18 1,152 19C 3x32x20 960 19D 4x27x20 1,080 19E 5x26x21 1,364 19F 4x26x18 936 19G 02016 768 19H 4x24x18 864 191 02012 576 191 5x20x10 500 19K 5x20x10 500 19L 5x20x10 500 19M 4x46x10 920 20A 3x42x6 378 21A 4x28x14 784 21B 4x30x16 960 21C 5x30x16 1,200 21D 4x30x16 960 22A 02602 624 228 4x26x12 624 22C 5x30x16 1,200 22D 03006 960 22E 03008 1,080 22F 02808 1,008 22G 5x29x20 1,450 22H 4x30x20 1,200 221 4x24x18 864 22J 5x26x16 1,040 22K 5x26x14 910 22L 5x24x14 840 22M 02014 672 23A 3x32x10 480 238 3x30x10 450 23C 3x28x8 336 Woodward-Clyde 0 W:\9651135FECO1-D-R.DOC1O-Mar-97\9651135F\SDG 34 SECTIONTHREE Early Action Measures Table 1 (Continued) SEDIMENT STORAGE CAPACITY OF TEMPORARY CHECK DAMS SAN MARCOS CREEK WATERSHED Check Dam Number - Check Dam Dimensions (crest to invert x length x depth, in feet) Estimated Sediment Holding Capacity Behind Check Dam (ft') 24A 0304 480 24B 4x30x8 480 25A 3x40x12 720 25B 3x40x10 600 26A 3x18x4 108 26B 3x20x6. 180 26C 3x18x6 162 26D - 3x20x4 120 27A 3x18x4 108 27B 3x18x6 162 27C 3x20x6 180 270 3x14x8 168 27E 3x20x6 180 28 305 (length) ND 29 140 (length) NDa 30A 4x26x0.5 26 30B 0402 176 ALL CHECK DAMS TOTAL - 118,169 a Not Determined Woodward-Clyde W9651135F\ECO1-D-R.DOC10-Mar-979651135F\SDG 35 I SECTIONF OUR Phase I Erosion and Sediment Control Plan This Phase I Erosion and Sediment Control Plan (Plan) was prepared for the Carlsbad area of the I Harmony Grove fire. The limits of the burn area and the limits of this study are shown on Figure 1. Development of any erosion and sediment control plan requires a stepwise process, which must be documentable and defensible. The key questions that must be answered are: When and where is erosion and sediment control needed? I • . How much is enough? The essential steps to be followed in developing a plan are as follows: I Step 1. Identify the Issues and Concerns Step 2. Develop Goals and Objectives Step 3. Perform.the Erosion and Sediment Yield Study Step 4. Develop Mitigation Measure Selection Criteria Step 5. Nominate and Evaluate Alternatives I . Step 6. Screen and Select Best Alternatives Step 7. Design the Erosion and Sediment Control Plans and Specifications Step 8. Implement the Plan I Step 9.. Operate and Maintain the System The following sections describe how each step was followed for development of.the City's I Erosion and Sediment Control Plan. I Phase 4.1 IDENTIFY ISSUES AND CONCERNS (STEP 1) . I . Based on discussions with the City and other affected parties, the identified issues and concerns for the areas of the City affected by the Harmony Grove Fire are as follows: I . • Public health and safety The potential for ash, debris, sediment, and flood damage to developed areas The impact of ash and sediment into Batiquitos Lagoon I . The interests of agencies having jurisdiction in the areas being addressed Environmental compatibility of the temporary mitigation measures 4.2 DEVELOP GOALS AND OBJECTIVES (STEP 2) Based on these identified issues and concerns, a set of goals and objectives for the Plan were I developed as follows: . Coordinate with concerned agencies and meet regulatory requirements I.. Reduce short-term erosion and sedimentation Maximize the use of cost-effective solutions . Maximize the use of environmentally-compatible solutions I . Provide mitigation options for transport of debris and sediment onto downstream property and sensitive water bodies . WOOdWaIdClyde W . W:9651135FEC01-D-R.D0C\1 1-Mar-97\9651 135FSDG 44 I I . SECTIONF OUR Phase I Erosion and Sediment Control Plan 4.3 PERFORM THE EROSION AND SEDIMENT YIELD STUDY (STEP 3) The erosion and sediment yield study includes the following tasks: Site reconnaissance and review of available information I . Field evaluation of the burn area Hydrology and sediment yield analysis Identification of potential mitigation locations I These tasks are described below. 1 4.3.1 Site Reconnaissance and Review of Available Information On November 11th and 12th, Woodward-Clyde performed preliminary field assessments to assist I in the identification of immediate action items to help protect the City-owned streets and storm drains from clogging with sediment. In addition Woodward-Clyde met with the Director of Engineering at the Resort of La Costa to tour the golf course area and to discuss appropriate I actions that the Resort could take to protect their property from increased post-fire flooding and sedimentation. Woodward-Clyde discussed pre-existing drainage problems in the golf course area with Mr. Cook. I Concurrent with the site reconnaissance, available information was reviewed. The following information was collected for this study: I . City of Carlsbad storm drain maps Initial burn area estimate map prepared by City of Carlsbad, dated October 1996 I . U.S.G.S. 7minute quadrangle topographic maps, dated 1975 and 1983 Two-foot topographic map of and prepared by the "Villages of La Costa," not dated I . U.S.G.S. Geologic maps "Hydrologic Studies of San Marcos Creek at the Rancho Santa Fe Road Bridge," prepared by I Rick Engineering, dated August 8, 1996 "Sediment Studies in the Final EIRJEIS for Batiquitos Lagoon," prepared by City of Carlsbad and the U.S. Army Corps of Engineers, dated June 1990 I . "Dredging and Grading Plan for Batiquitos Lagoon," prepared by Moffatt & Nichol, Engineers, dated December 17, 1993 I • Harmony Grove Fire Area map overlain with the drainage areas, prepared by City of Carlsbad, dated October 1996 I . Soil Conservation Service Soil Survey Maps and two-volume text, dated December 1973 . Aerial photographs (scale: 1 in. 1,310 ft) for pre- and post-bum conditions, dated I November 1996 . County of San Diego Hydrology Manual, dated 1985 1 . Woodward.Clyde W:\9651 135EECO1-D-R.DOC\11-Mar-979651135F\SDG 4-2 I SECTIONF OUR Phase I Erosion and Sediment Control Plan State of California, The Resources Agency, Department of Water Resources, "Rainfall Analysis for Drainage Design, Volume 1. Short-Duration Precipitation Frequency Data," I dated 1975 San Marcos Creek Floodplain Information, prepared by U.S. Army Corps of Engineers, dated 1 April 1971 "Local Climatological Data Annual Summary with Comparative Data - 1993, San Diego, I CA," U.S. Department of Commerce - NOAA, National Climatic Data Center Using the topographic maps, aerial photographs, drainage maps, and field observations, Woodward-Clyde reviewed the size and condition of natural drainages affected by the fire. We also observed the condition of the burned slopes in the fire area, as well as the relationship of the surviving vegetation and drainage facilities to the burn areas and, based on those observations, identified potential locations and control measures for the areas within and downstream of the I burned area. In addition to the field reconnaissance, suppliers of erosion control materials and erosion control ' contractors were contacted to obtain information on prices and availability of alternative candidate control measures. 4.3.2 Field Evaluation of the Harmony Grove Fire Area in Carlsbad The majority of the Carlsbad burn area is within the watershed of the large east-west trending I drainage of San Marcos Creek. This area is known as Rancheros and drains to the sensitive coastal receiving water body, Batiquitos Lagoon, via "Box Canyon," a deep and narrow drainage I reach of San Marcos Creek. A $55 million restoration project that included the creation of new wetland habitat area and nesting islands in the lagoon was completed in January, 1997. Tidal flushing will be restored to the lagoon by artificially opening the lagoon mouth to the Pacific I Ocean. In general, the watershed slopes around San Marcos Creek downstream of the Lake San Marcos Dam were 80 to 100 percent burned. There is visible evidence of active erosion on these slopes. I A number of homes on the ridge of south side of Box Canyon were destroyed by the fire. There is a potential for soil to erode from the slopes of Box Canyon and be transported as sediment in the creek and into the Resort of La Costa golf course. If the water and sediment volume is large I enough, overbank flow laden with sediment could spread onto the golf course. The flow would ultimately continue through the golf course and potentially impact Batiquitos Lagoon. I On November 12th, 1996, Woodward-Clyde's field assessment team, comprised of civil and geotechnical engineers with backgrounds in hydrology, hydraulics, erosion, and sediment transport, performed further field evaluations of the burn, area. The evaluation included I documentation of the site characteristics (topography, soils, vegetation, etc.), drainage information, erosion and sedimentation information, and mitigation planning information. Written and photographic documentation were prepared. The completed field assessment was then summarized and utilized for selection and prioritization of areas for mitigation. Li Woodward-Clyde W W:\9651135F\ECO1-D-R.DOC\12-Mar-97\9651 135F\SDG 43 I SECTIONF OUR Phase I Erosion and Sediment Control Plan Two subsequent site visits were made by our erosion and sediment control specialist with Dick I Cook from the City on November 27th and December 16th. The purpose of the site visits was to make field visits to specific, localized areas that were of concern to the City. Descriptions of these localized areas and our recommendations are provided in Appendix D. 4.3.3 Hydrology and Sediment Yield Analyses I Hydrology and sediment yield analyses were performed to determine the peak discharge in cubic feet per second, the volume of discharge in acre-feet, and the total sediment yield in tons per acre per year, for both pre-burn and post-burn conditions. These analyses were performed for San I Marcos Creek downstream of Lake San Marcos. An additional analysis was performed to evaluate the effects on the peak flow of a 5-foot I . drawdown in Lake San Marcos for post-burn conditions. Lake San Marcos is formed by a concrete arch dam located approximately 7.75 miles upstream of the mouth of San Marcos Creek. The dam was completed in 1952, and the lake is used as a recreation area with finger I piers and docks extending into the lake for the mooring of privately-owned boats. The Lake San Marcos development around the lake includes single-family homes, condos, and a golf course. San Marcos Dam is approximately 45 feet high and 300 feet in length. There are no operating I gates in the dam, so the lake level is not controlled. As a result, the reservoir is usually full to the dam crest, which allows the dam to act as a weir. The lake, therefore, in its present condition (i.e., full) would have little to no effect on attenuating the peak or volume of flows in San Marcos I Creek downstream, aside from some minimal storage on the surface of the lake. The hydrologic analysis was performed for selected concentration points in the watershed using I the Army Corps of Engineers HEC-1 Flood Hydrograph Package. The HEC-1 model is designed to simulate the surface runoff response of a river or creek basin to precipitation by representing the basin as an interconnected system of hydrologic and hydraulic components. Each component I models an aspect of the rainfall-runoff process within a portion of the basin, commonly referred to as a subbasin. A component may represent a surface runoff entity, a stream channel, or a reservoir. The result of the modeling process is the computation of streamfiow hydrographs at I desired locations in the river basin. The results of the HEC-1 analysis for the study area are provided in Appendix A and summarized I in Table 2. The model was run for the pre-burn condition, post-burn condition, and post-burn condition with 5 feet of drawdown of the water level in Lake San Marcos, and flow peaks and volumes were calculated at various concentration points within the San Marcos and Encinitas I Creek watersheds for the 2-year 6-hour, 25-year 6-hour, 50-year 6-hour, and 100-year 6-hour storms. I Figure 2 presents the location of each contributing drainage area and corresponding concentration point. The results indicate that for the post-burn 2-year 6-hour storm event a 10 to 20 percent increase in the peak discharge will occur in San Marcos Creek, and a 40 percent I Woodward-Clyde 0 W:\96511 35F\ECO1-D-R.00C11-Mar-979651135FSDG 44 I - - - - - - - - - - - - - - - - - - - SECTIONFOUR Phase I Erosion and Sediment Control Plan Table 2 SUMMARY OF RESULTS FROM HEC-1 FLOOD HYDROGRAPH ANALYSIS 2-year 6-hour Storm 25-year 6-hour Storm Co ncentration Post-Burn with Post-Burn with Point Units Pie-Bum Post-Bum Drawdowna Pie-Burn Post-Burn Drawdowna Lake San Marcos Dam Q (cfs) 612 686 --- 4,608 4,876 4,760 (at spillway crest) Volume (ac-ft) 241 272 -- 1,691 1,781 1,486 Arizona Crossing Q(cfs) 611 717 38 4,816 5,264 5,149 Volume (ac-ft) 241 282 10 1,769 1,943 1,659 El Camino Real Bridge Q (cfs) 688 835 104 5,577 6,038 5,852 Volume (ac-ft) 277 318 45 2,111 2,285 2,003 Batiquitos Lagoon Q (cfs) 735 931 243 6,184 6,787 6,572 (at mouth of San Marcos Creek) Volume (ac-if) 302 368 95 2,375 2,628 2,346 Encinitas Creek Q (cfs) 79 143 143 868 1,185 1,185 (at confluence with San Marcos Creek) Volume (ac-ft) 25 49 1 49 264 f 343 343 50 -year 6-hour Storm 100 -year 6-hour Storm Concentration Post Burn with Post-Burn with Point Pie-Bum Post-Bum Drawdowna Pre-Burn Post-Burn Drawdowna Lake San Marcos Dam Q (cfs) 5,936 6,262 6,177 7,321 7,668 7,624 (at spillway crest) Volume (ac-if) 2,150 2,251 1,956 2,618 2,728 2,433 Arizona Crossing Q (cfs) 6,242 6,766 6,701 7,717 8,282 8,268 Volume (ac-if) 2,264 2,467 2,187 2,776 3,005 2,714 El Camino Real Bridge Q (cfs) 7,232 7,784 7,668 8,961 9,543 9,525 Volume (ac-ft) 2,707 2,910 2,631 3,327 3,557 3,267 Batiquitos Lagoon Q (cfs) 8,053 8,762 8,645 9,960 10,765 10,691 (at mouth of San Marcos Creek) Volume (ac-ft) 3,054 3,347 3,068 3,759 4,089 3,799 Encinitas Creek Q(cfs) 1,172 1,544 1,544 1,487 1,916 1,916 (at confluence with San Marcos Creek) Volume (ac-if) 347 437 437 432 532 532 a "Drawdown indicates a 5-foot lowering of the water level in Lake San Marcos from the dam crest elevation. Woodward-Clyde @ W:9651135F\EC01-D-R.00C11-Mar-97\9651 135F\SDG 45 I SECTIONF OUR Phase I Erosion and Sediment Control Plan I increase in peak flow at the confluence of San Marcos Creek and Encinitas Creek is possible. I However, by drawing down the water level in Lake San Marcos five feet, a 67 to 94 percent decrease in peak discharge is possible for the 2-year 6-hour storm through San Marcos Creek. From our previous experience, it is anticipated that post-fire storm flows will gradually decrease 1 to pre-burn conditions over the next 3 to 5 years. The sediment yield analysis was performed using the Flaxman Sediment Yield Method for both the pre-burn and post-burn conditions. - Elliot Flaxman published a predictive equation which relates sediment yield as a dependent variable to five independent watershed characteristics. The equation was derived from empirical data in areas where the terrain afforded a close relationship between erosion and sediment yield, and that gully and channel erosion were not significant contributors. The Flaxman equation is as i follows: . . Y° = -86.07 - 5.30 (X1)°5 + 7.33 (X2)°5 - 1.63 (X3)05 + 10.79 (X4)° + 0.92(X5)°5 I where: Y = average annual sediment yield in tons per square mile I . X 1 = (PIT)/l .43 with PIT expressed as percent P = average annual precipitation, inches I , T = average annual temperature, degrees F X2 = average slope of the watershed in percent 1 . X3 = percentage of particles coarser than 1.0 mm in the surface 2 inches of soil divided by 72 (expressed as a percent). X4 = percentage of clay in the surface 2 inches of soil plus 100 (if the pH of the soil is I greater than 7), and 100 minus the percent clay (if the pH is equal to or less than 7) I ,X5 = the 50 percent chance peak discharge in cubic feet per second per square mile For the purposes of this study local precipitation and temperature data were collected from "Local Climatological Data Annual Summary with Comparative Data - 1993, San Diego, CA," I U.S. Department of Commerce - NOAA, National Climatic Data Center, as follows: Precipitation: 1964-1993 9.97 inches (average) Temperature: 1964-1993 , 62.4 °F (average) The sediment yield analysis using the Flaxman method was performed for both pre-bum and I post-burn conditions, and the average annual sediment yield was calculated at two concentration points each in San Marcos Creek and Encinitas. Creek, and a total sediment yield into Batiquitos Lagoon was calculated. Tables 3 and 4 provide the pre- and post-burn results, respectively. I WOOdWard-Clyde W:\9651 135F\ECO1-D-R.DOC12-Mar-97\9651135FSDQ 4-6 I SECTIONFOUR Phase I Erosion and Sediment Control Plan Table 3 SEDIMENT YIELD ANALYSIS FLAXMAN METHOD - PRE-BURN CONDITION Area Lake San Marcos to Rancho Santa Fe Road Arizona Crossing to Rancho Santa Fe Road Encinitas Creek. East of Rancho Santa Fe Road Encinitas Creek- East of Olivenhain Road Total Sediment Yield at Batiquitos Lagoon Xl 0.11 0.11 0.11 0.11 X2 '34 26 20 17 X3 7 14 7 8 X4 21 38 .25 26 X5 688 226 99 125 Yl 506 488 5 2 1,001 tons/sq. mi Y2 0.8 0.8 0.008 1 0.003 1 1.6 tons/acre Table 4 SEDIMENT YIELD ANALYSIS FLAXMAN METHOD - POST-BURN CONDITION Area Lake San Marcos to Rancho Santa Fe Road Arizona Crossing to Rancho Santa Fe Road Encinitas Creek- East of Rancho Santa Fe Road Encinitas Creek- '. East of Olivenhain Road Total Sediment Yield at Batiquitos Lagoon Xl 0.11 0.11 0.11 0.11 X2 34 ' 26 20 17 .X3 7 14 7 .8 X4 21 38 25 26 X5 771 266 179 ' 227 "(1 572 540 29 24 1,165tonslsq.mi Y2 0.9 ' 0.8 ' 0.05 1 0.04 1.8 tons/acre As can be seen from the results above, the average annual sediment yield from the watershed below Lake San Marcos increases from 1.6 tons per acre for the pre-burn condition, to 1.8 tons per acre for the post-bum condition. This represents a 12.5 percent increase in sediment yield from the watershed. It is our experience with past fires that this condition will gradually reduce to' the pre-bum conditions over the next 3 to '5 years, as the vegetation grows back and the watershed stabilizes. The results of the pre-burn sediment yield analysis were compared with the sediment yield results in the Final EIRJEIS for Batiquitos Lagoon, and the results appear to be consistent. Because water-generated erosion is the result of two types of erosive actions: raindrops falling and striking bare ground, and runoff traveling over the land, even moderate storm events could I Woodward-Clyde W:\9651135F\ECO1-O.R.DOC11-Mar-97\9651 1 35F\SDG 47 I i I I I L I 1 I I SECTIONF OUR Phase I Erosion and Sediment Control Plan potentially create significant erosion impacts. In addition the lack of vegetation after a major fire ' increases the flow velocity off slopes and leads to increased erosion and transport of sediment downstream. Once raindrop impact loosens soil particles and splashes them into the air, they can be moved by I water traveling over the land. Sheet erosion is caused by shallow sheets of water flowing over the land, carrying soil particles. As the water flows, it concentrates in surface irregularities, and ' erodes rills and gullies. As channels are eroded, the velocity of the water increases and greater amounts of soil are washed away. This increase in sediment transport downstream causes road culverts to clog, roads to be covered with sediment, and may result in public and private property I damage. A volumetric comparison was conducted relating the total estimated annual sediment yield from the San Marcos Creek watershed for the post-burn condition, and the estimated sediment holding I capacity behind the temporary gravel bag check dams and within the Arizona crossing detention basin. It is estimated that approximately 9,000 tons of sediment holding capacity is available for I these structures. Using the Flaxman method, it was estimated that 1.7 tons per acre per year of sediment would be yielded from the San Marcos Creek watershed downstream of Lake San Marcos. These results indicate that the check dams and the detention basin should provide I sufficient capacity for approximately 2 years assuming that no maintenance (dredging the detention basin or removing sediment from behind the temporary check dams) is performed. Naturally, this period could vary .depending on the nature of the actual storms. 4.3.4 Potential Mitigation Measure Locations I Erosion control measures, such as applying hydraulic mulches and binders to the burned slopes was considered, but for several reasons was not recommended. At the time of our field investigation and preparation of this report, the area experienced several low intensity, long 'I duration storms followed by warm weather. This fortunate sequence of weather events served to promote the rapid regrowth of vegetation in the burned area, which has grown in some areas as high as 6 to 8 inches. The species that are growing the fastest appear to be grasses, which I provide good cover for the soil, and help reduce erosion of the slopes. This condition, combined with prohibitive costs of applying hydraulic measures over widespread areas, was the basis for not recommending erosion control measures, and focusing instead on strategically sited sediment I control measures. Based on the hydrology and sediment yield analyses described above, the areas that were I identified as offering the best opportunities for sediment control in the study area are: Arizona Crossing ' The Arizona Crossing provides a good opportunity and broad location for trapping sediment prior to discharging downstream. The crossing is readily accessible to large equipment that can be utilized for sediment removal and maintenance of the detention basin. I I Woodward-Clyde @ W:9651135FECO1-D-R.DOC11-Mar-979651135F\SDG 4-8 I SECTIONFOUR Phase I Erosion and Sediment Control Plan Box Canyon Box Canyon has a relatively narrow creek channel to install temporary sediment control structures. However, the limited accessibility, steepness of the channel and side slopes, and magnitude (volume, flow rate, and velocity) of flows would have to be evaluated prior to the design and installation of sediment control measures. Lake San Marcos Lake San Marcos provides an opportunity to trap both water and sediment from the upstream watershed of San Marcos Creek. The lake is relatively deep (up to 80 feet), and the docks are floating which allows them to tolerate changes in water surface elevation. By lowering the lake level below the dam crest between major storm events, considerable storage capacity could be provided for water and sediment from the watershed above the lake. This option would considerable reduce the peak and volume of flow and sediment in San Marcos Creek downstream of the dam that discharges to Carlsbad. These are shown on Figure 1. 4.4 DEVELOP MITIGATION MEASURE SELECTION CRITERIA (STEP 4) The severity of the erosion and sedimentation potential within the affected area and the degree of damage that could occur from downslope delivery of ash, debris, and sediment necessitates the use of the best practical and available technology. In addition, a wide range of conditions requires a variety of solutions designed to address sediment control under site-specific circumstances. The mitigation measures selected for implementation by the City should be evaluated utilizing the following criteria: Cost-Effectiveness: Performance histories, both field and laboratory, must be evaluated for a number of materials and techniques and compared to relative material costs. AvailabiliIy. The material must be readily available from a local supplier or be capable of immediate shipment to the area within the timeframe designated by the plans. Feasibility: The material must be capable of relatively quick and easy application with minimal training required to orient crews or contractors to proper application procedures. Each material should be considered for its flexibility or applicability to a variety of field conditions. I Woodward-Clyde W:19651 135F\ECO1-D-R.DOC1 1-Mar-97\96511 35FSDG 49 I I I I I I I I I I I I SECTIONFOUR Phase lErosion and Sediment Control Plan Durability: S Given the severity of site conditions, with slope gradients sometimes exceeding 65 degrees, it is necessary that erosion and sediment control measures maintain their integrity during high flows and persist until vegetation has established effective erosion control cover. Compatibility: Materials should be selected with regard to public acceptability and environmental sensitivity. 4.5 NOMINATE AND EVALUATE ALTERNATIVES (STEP 5) This section presents a description of alternative measures for erosion and sediment control measures recommended for use in the Carlsbad area. A meeting was held on November 21st, 1996 between Woodward-Clyde and the City of Carlsbad to discuss the alternatives to be incorporated into this Phase I Plan. Table 5 identifies specific options presented to the. City. Woodward-Clyde and the City subsequently identified their preferred alternatives and those that were most feasible for implementation. The selected alternatives are presented in Section 4.6, Screen and Select Best Alternatives (Step 6). 5 Woodward-Clyde @ W:\9651135F\ECO1-D-RDOC11-Mar-979651135F\SDG 4-10 mm mm — MM — — — — - — — — — MW — SECTIONFOUR Phase I Erosion and Sediment Control Plan Table 5 EROSION AND SEDIMENT CONTROL MEASURE ALTERNATIVES Relative Relative Location Alternative Cost Advantages Disadvantages Capacity Box A. Utilize geoweb to construct layered 2- to A. Low A. Native on-site materials, (rocks, debris, etc.) can be A. and B. A. Low Canyon 3-foot high check dams within the utilized. Access to canyon is prohibitive. canyon. Flexible, can take high loads, strong. Can only be constructed to certain height due to excess hydraulic loading leading to failure. B. Utilize geogrid to construct tubular 3- to B. Low B. Native on-site materials, (rocks, debris, etc.) can be B. Low Requires trenching and staking which may be 4-foot high check dams within the utilized. Strong, light-weight material; can difficult due to shallow bedrock. canyon. withstand excessive loading. Slope of canyon limits sediment capacity. C. Utilize rock filled gabions to construct C. Medium C. Native materials (rocks, etc.) can be utilized. C. Cumbersome. Removal can be difficult. C. Low flexible check dams within the canyon. Flexible, strong, can take' high loads. D. Utilize erosion control measures on D. High D. Provides protection from raindrop and wind D. Extent of area too large to be cost effective. D. Low slopes tributary to Box Canyon. impacts. E. No action E. N/A E. None E. Increase in peak flow. E. None Arizona A. Elevate the roadbed at the Arizona cross- A. Medium A. and B. , A. Periodic sediment removal after storms A. Moderate Crossing ing approximately 2 to 3 feet using 9-inch Easily accessible. necessary. ' to high gabion mattresses or geoweb to increase Upstream from sensitive receptors. sediment retention capacity. Install rip- Area available to create moderate sediment rap on up- and downstream face. retention capacity. B. Elevate the roadbed at the Arizona B. Medium B. Periodic sediment removal after storms B. Moderate Relatively uncomplicated maintenance procedures. crossing approximately 2 to 3 feet using Area conducive to wetland habitat enhancement. necessary. to high a gravel base overlain by asphalt- concrete to increase sediment retention capacity. Install riprap on up- and downstream face. C. Install K-rail on the upstream and down- C. Low C. Quick to install and remove. C. K-rail may require anchoring to keep from C. Moderate stream sides of the Arizona crossing, and sliding. to high fill between with compacted soil. D. No action D. N/A D. Basin is currently accessible for cleaning out and D. Requires more frequent sediment removal than D. Low to has some sediment retention capacity. other alternatives due to lower capacity. moderate Woodward-Clyde 0 W:9651135FEC01-D.R.D0C11-Mar-97\9651135FSDG 4-11 — — — — — No ON — — — — - - - - - - - - SECTIONFOUR Phase I Erosion and Sediment Control Plan Table 5 (Concluded) EROSION AND SEDIMENT CONTROL MEASURE ALTERNATIVES Relative Relative Location Alternative Cost Advantages Disadvantages Capacity Resort of A. Clean out sediment, debris and A. Low A. Will provide a small increase in flow capacity of A. None A. Moderate La Costa vegetation from channel. . channel through golf course. Golf Course B. Utilize HDPE geotextile tubes filled with B; High B. B. B. Moderate water along channel banks to temporarily Increases flow capacity in channel through golf Aesthetically incompatible with golf course increase channel capacity. course by adding 4 to 5 feet of additional setting and usage unless creative landscaping freeboard. is utilized as temporary camouflage. Can be quickly and easily installed and removed Temporary modification of golf cart bridges may during the winter rainy season. be required. May be reused every year. C. No action. C. N/A C. None C. Flooding on golf course C. Low Lake San Draw down water level in Lake San Marcos 5 Moderate Stores sediment and water in lake from upstream Not within City jurisdiction. High Marcos to 6 feet between storms to reduce peak watershed, thus reducing peak flows and sediment Would require pumping since the dam has no flows downstream. loads downstream in Carlsbad. outlet control. Woodward-Clyde @ W:9651 135FECo1-D-R.DOC\1i.Mar-97\9651 135FSDG 4-12 I SECTIONF OUR Phase I Erosion and Sediment Control Plan The following is list of alternative erosion and sediment control measures identified for use in the I City: • SF1 Prefabricated Silt Fencing G132A Gravel-filled Burlap Bag Check Dams I . • GB213 Gravel-filled Burlap Bags for Inlet Filter • G132C Gravel-filled Burlap Bag for Curb Inlet Filter I . CC3 Cellular Confinement System • GM4 9-inch Gabion mattress. • FC5 Flexible Concrete Revetment I . KR6 Concrete Traffic. Barriers (K-rail) • TL7 . Temporary Levees I . • DM8 SB9 Straw Mulching with Tackifier or Nets Straw Bales . BM1O Bonded Fiber Matrix EB11 Erosion Control Blankets I s HS 12 Hydraulic Soil Sealing These erosion and control sediment control measures and local sources are described below. It I should be noted that some measures have been included for information purposes in the event future conditions require their use. SF1 Prefabricated Silt FenciAg I Description Filter fences prefabricated from woven geotextile with attached posts are proposed for limited use in the firestorm area. The sediment retention structures are generally 3 feet in height and I 100 feet in length, with wooden 1-in. x 1-in. x 36-in, stakes spaced every 8 to 10 feet along the length of the fabric. I Silt fences function by retaining sediment behind the geotextile fabric, while allowing water to flow through. In order to be effective, the bottom of the fabric must be placed in a trench, backfilled with soil and compacted to keep water from flowing under the fence. Silt fence has limited use in the burn area, primarily as debris fences when work crews are on slopes, to prevent debris from cascading Off slopes. When used for sediment control, they should be periodically inspected and repairs made after each storm event. Sediment and other deposited I material should be removed before the material reached one-half the fence height. H F7 I Woodward-Clyde W:\9651135FECO1-D-R.DOC1 1-Mar-979651 135F\SDG 4-13 SECTIONFOUR Phase I Erosion and Sediment Control Plan Sources Two sources of silt fencing have been identified in San Diego County: Drainage Products, Inc. 444 Via El Centro Oceanside, CA 92054 Tel: (619) 757-7211 Fax: (619) 757-7214 ACME Bag Company Inc. 2528 Main Street, Suite A Chula Vista, CA 91911 Tel: (619) 429-9800 Cost Costs are variable ranging from $1.00 per linear foot to $1.40 per linear foot depending on grade of geotextile and size of stakes. I GB2A Gravel-Filled Burlap Bag Check Dams GB2B Gravel-Filled Burlap Bags for Inlet Filter I GB2C Gravel-Filled Burlap Bag for Curb Inlet Filter Description I Burlap bags filled with 1 inch minimum clean gravel can be used in the fire area in a variety of applications. The use of the gravel in a biodegradable textile of open weave allows water to percolate through the system, while retaining sediment behind the bag. The bags can be place by workers in the following situations: As velocity reduction and sediment retention structures in incised gullies, particularly those I on slopes which are active or have the potential for massive sediment transport during storm events. The bags should be placed under the guidance of field engineers, stacked alternately to a depth of no more than 24 inches and with the middle flow line portion of the bag weir I lower than the sides; 24-inch stakes may be driven in front of the downstream portion of the bag-wall for additional support (Practice GB2A). This practice may also be adapted for use as linear sediment barriers along roads or at the base of slopes. As filter barriers for storm drain inlets, where the bags are placed in alternating rows around the perimeter of the drain (Practice GB2B). 1 3. As filter barriers for storm drain curb inlets, in which case they will be place in alternating fashion, two bags high, in a semi-circle in front of curb storm drain inlets (Practice GB2C). I 4. As velocity reduction and sediment retention structures along the curbs of roads, where a line of alternating bags, 2 feet high and 8 to 10 feet long will be extended up gradient and away from the curb at an angle not to exceed 30 degrees (Practice GB2C). I Woodward-Clyde W:\9651135F\ECO1-D-R.DOC11-Mar-979651135FSDG 4-14 I SECTIONFOUR Phase I Erosion and Sediment Control Plan An option is for gravel filled bags to be kept within a short distance of the storm drain inlets and thereby ready for immediate deployment before or during rainfall events. Field engineers, under the direction of the City, may paint a dashed line prior to storm events on the pavement and away from the curb, indicating the positioning of the gravel bags. Sources Two local sources for burlap bags are: JAM Compaction and Erosion Control 2649 Vista Way, Suite 8-21. Oceanside, CA 92054 Tel: (619) 722-2285 Fax: (619) 722-1055 ACME Bag Company, Inc. 2528 Main Street, Suite A Chula Vista, CA 91911 Tel: (619) 429-9800 Costs Costs are variable, ranging from $0.40 to $0.60 per bag Price breaks may be negotiated depending on quantity. CC3 Cellular Confinement System Description Geoweb and EnviroGrid are lightweight flexible cellular confinement systems constructed of either polyethylene or metal. The system consists of three-dimensional cells in a honeycomb- like structure. After installation with on-site fill material or rock, geogrid acts as a semi-rigid slab, distributing loads laterally, and reducing subgrade contact pressures. When combined with on-site fill or rock materials geogrid creates an economical structural base for temporary roads, permanent roads or pad site construction. Sources One source for Geoweb is: Presto Products Company P.O. Box 2399 Appleton, WI 54913-2399 Tel: (800) 548-3424 Fax: (414) 738-1418 Woodward-Clyde W:\9651135F\ECO1-O-R.DOC11-Mar-9751135F\SDG 4-1 5 I I SECTIONF OUR Phase I Erosion and Sediment Control Plan One source for EnviroGrid is: I Drainage Products, Inc. 444 Via El Centro I Oceanside, CA 92054 Tel: (619) 757-7211. Fax: (619) 757-7214 I Costs The cost for cellular confinement systems is approximately $1.40 per square foot plus $0.10 per I square foot for installation. Cost for fill material or washed rock is not included in quoted installation and material costs. GM4 Gabion Mattresses or Baskets Description Gabions are fabricated from welded, corrosion-resistant, steel, wire interlock mesh formed into large boxes, usually rectangular in shape but variable in size. They are designed to reduce the complex problems of erosion, sedimentation, and flooding at relatively low cost. Gabions are erected at the project site, quickly joined together and filled with stones, often obtained on site. They can be handled as building blocks to form monolithic, permeable, flexible structures of any size and shape. Because of their inherent flexibility, gabion structures can yield to earth movement and retain their full efficiency while remaining structurally sound. Sources Four sources for gabions are: Maccaferri Gabions, Inc. 3650 Seaport Blvd. West Sacramento, CA 95691 Tel: (916) 371-5805 Terra Aqua Gabions P.O. Box 7546 Reno, NV 89510 Tel: (702) 828-1390 Fax: (702) 828-1394 Hilficker Retaining Walls 3900 Broadway (99503) P.O. Box 2012 Eureka, CA 95502-2012 Tel: (707) 443-5093 Fax: (707) 443-2093 Woodward-Clyde 40 W:\9651135F\ECO1-D-R.DOC\11 -Mar-97\9651135F\SDG 4-16 I SECTIONFOUR Phase I Erosion and Sediment Control Plan Modular Gabion Systems, Inc. P.O. Box 230150 Houston, TX 77223-0150 Tel: (800) 324-8282 or (334) 633-2393 Fax: (334) 633-4188 Cost I Costs are variable for 9-inch gabion mattresses, ranging from approximately $30 to $35 per square yard installed. Material costs range from $10 to $15 per square yard. Additional costs would be incurred from overlaying the gabion mattress with asphalt. FC5 Flexible Concrete Revetment I Description Flex-block (from Drainage Products, Inc.) or Armorfiex (from Erosion Technology, Inc.) are I interlocking matrices of precast concrete blocks of uniform size, shape, and weight, interconnected by a series of cables which pass through preformed ducts in each block. The ducts allow for drainage and vegetation growth through the matrix. The interlocking blocks are I made into mats for use in channel lining, river bank protection, drainage ditch lining, pipeline protection, bridge abutment protection, dam crests and spillways, and weirs and overflow basins. I Sources - One local source for Flex-block is: I Drainage Products, Inc. 444 Via El Centro Oceanside, CA 92054 I Tel: (619)757-7211 Fax: (619) 757-7214 One local source for Armorfiex is: Erosion Technology, Inc. Jim Fish I P.O. Box 441 7367 Noche Tapatia I Rancho Santa Fe, CA 92067 Cost The cost of flexible concrete revetment materials is approximately $4.00 per square foot, plus I $2.00 per square foot for installation. I Woodward-Clyde W.\9651135FEC01-D-R.DOC\11Mar-979651135SOG 417 SECTIONF OUR Phase I Erosion and Sediment Control Plan KR6 Concrete Traffic Barriers (K-rail) Description This practice involves the placement of concrete or water-filled plastic traffic barriers, also known as "K-Rail," in areas of potential sediment loads to direct the material away from significant resources or create capacity in a basin. Key considerations when using this practice are access to the area of placement and operation and maintenance once in place. Barriers are placed end-to-end in a predesigned configuration and gravel-filled bags are used at the upstream toes of the barriers and also at their abutting ends to seal and prevent movement of sediment beneath or through the barrier walls. These systems should be used only after an evaluation of the debris potential and only when the flow can be directed onto areas where it will not cause significant impacts. K-rail may also be used to increase the size of upstream retention by placing two rows of K-rail with compacted soil in between them. Costs for K-rail are usually nominal if the City has K-rail available. Concrete barriers require a crane to install, while plastic barriers may be installed by hand and filled with water on site. TL7 Temporary Levees Description Temporary levees, or Water Structures®, are based on a patented idea that combines three or more polyethylene or woven geotextile tubes and any available water supply. Two "inner" tubes, contained by an outer "master" tube, are pumped full of water simultaneously. Counter friction between the master and inner tubes results in a stable, non-rolling "wall" of contained water, which adjusts automatically to- bottom terrain. The result is a temporary water structure dam. Water structures are light, easy to handle, temporary, and can be used in virtually any location. Available sizes range from 1 foot to 10 feet high. Water Structures® were recently used along the Mississippi River to help reduce flooding of adjacent areas. Sources One source of Water Structures® is: Water Structures Unlimited P.O. Box 206 Carlotta, CA 95528 Tel: (707) 768-3439 Fax: (707) 768-1723 Cost The cost for a 3-foot high, 68-inch wide, 1,130 lb./linear foot water structure is $24/foot installed. Discounts are available for large quantity orders. Woodward-Clyde W:\9651 135F\ECO1-D-R.DOC11-Mar-97\9651135F\SDG 4-18 I SECTIONFOUR Phase I Erosion and Sediment Control Plan DM8 Straw Mulching with Tackifier or Nets Description Weed-free, bright straw can be' used as part of a three-step surface erosion control practice. Straw mulching,can also be anchored with nets, which is primarily a homeowner practice. The three-step process is economically impractical on small, individual lots. See Appendix B for details. Sources The following suppliers can provide wood fiber mulch and/or tackifier for the three-step process: Tackifier: S&S Seeds P.O. Box 1275 Carpenteria, CA 93103 Tel: (805) 684-0436 Fax: (805) 684-2798 Wood Fiber Mulch: Weyerhaeuser Company 7001 396th S.E. Snoqualmie, WA 98065 Tel: (800) 443-9179 Fax: (296) 888-7504 Acrylic Copolymer: Environmental Soil Systems, Inc. 13234 Whistler Avenue Granada Hills, CA 91344 Tel: (800)368-4115 Fax: (818)368-9393 Jute Netting: Santa Fe Bag Company 102 Varni Road Corralitos, CA 95076 ' Tel: (408)728-9359 Fax: (408) 728-4672 Dayton Bag & Burlap 322 Davis Avenue Dayton, OH 45403 Tel: (513) 258-8000 Fax: (513)258-0029 Woodward-Clyde 0 W:\9651135F\EC01-D-R,DOC\l1Mar.97\9651135F\SDG 4-19 SECTIONFOUR Phase I Erosion and Sediment Control Plan Belton Industries, Inc. 8613 Roswell Road, No. 200 Atlanta, GA 30350 Tel: (800) 225-4099 Fax: (404)992-6361 Synthetic Netting: Conwed Plastics 2690 Patton Road Roseville, MN 55331 Tel: (612) 831-5720 Synthetic Industries 4091 Industry Drive Chattanooga, TN 37416 Tel: (800) 621-0444 Fax: (615)449-0753 Costs Typical costs for the three-step practice, including materials and application, range from $1,250 to $1,450 per acre, without seed. SB9 Straw Bales Description I Straw bales may be used for check dams to temporarily stabilize gullies and channels, as storm drain inlet filters, or a perimeter filter barriers. To be effective, bales must be installed in a I trench (generally no deeper than 4 inches), with the strings placed to the side, and held in place using 1-in. x 1-in. x 36-in, wooden stakes. When used as temporary perimeter barriers along roads, trenching may not be necessary. I When used as check dams, the edges must be higher than the center point; and the crest of the downstream check dam should be approximately level with the toe of the upstream check dam., Straw bales may be used as storm drain inlet filters where the area around the drain is composed Of soil. Bales should weigh between 40 and 60 lbs. Finally, it is important that any allotment of straw be I bright and dry when purchased and covered or otherwise protected from rain until use. Sources A wide range of agricultural sources for straw exist, but it is essential that only weed-free rice straw or wheat straw be used, so as to reduce the potential for spread of unwanted plants onto the - burn area. I S Woodward-Clyde W:\9651135F1EC01-D-R.DOC\11-Mar-979651135SDG 4-20 I I SECTION FOUR Phase I Erosion and Sediment Control Plan Costs I Prices for straw bales range from $3.25 for wheat straw to over $7.00 for heavy bales of rice straw. BMIO Bonded Fiber Matrix I Description A bonded fiber matrix (BFM) is a hydraulically applied erosion control blanket composed of wood fibers held together by a high strength adhesive. Upon cross-linking, the adhesive holds the wood fibers together in a three-dimensional matrix which prevents erosion from rainfall splash and overland sheet flow. One of the unique features of the BFM is that once cross-linked, I rewetting of the matrix does not affect the bond strength, and field and laboratory evaluations• have shown the matrix to be just as effective in controlling erosion as standard, roll-type erosion control blankets. The BFM is delivered in standard 50 pound bags and is added to a hydraulic seeder tank much in the same manner as conventional hydraulic mulch. However, application is somewhat different as the applicator is required to "build a blanket" rather than just spray mulch and seed. In this I regard, care must be given to thickness of application and elimination of "shadow effect" during application. The BFM may be used with or without seed but exhibits its best performance when used in combination with seeding mixtures. It is a straw yellow color when applied, gradually I weathering to an earthen-tone brown over time. A BFM may be used on slopes around high-priority areas, and in general, where steepened slope I conditions and safety concerns preclude the installation of erosion control blankets. Source I Although there are quite a few companies that make components which can be combined to simulate a BFM, only one company currently manufactures a "one-bag" system: I Weyerhaeuser Company 7001 396thS.E. Snoqualmie, WA 98065 I Tel: (800)443-9179 Fax: (296) 888-7504 I . Costs Current pricing (based on an application rate of 3,000 pounds per acre) is about $5,000 per acre for labor and materials. I. I I Woodward-Clyde W:\9651135FECO1-D-R.DOC\11-Mar-97\965l 1 35F\SDG 421 1 SECTIONFOUR Phase I Erosion and Sediment Control Plan EBII Erosion Control Blankets I Description Erosion control blankets (ECBs) are rolled materials which contain plant fibers (straw, coconut fiber or wood fiber) held between plastic netting. When used following seeding, the ECBs are rolled our in the direction of water flow and held in place using 6-in. x I-in. x 6-in, wire staples. I ECBs may be used on those areas where a high velocity water channel requires protection or on steepened slopes above existing homes, and then only if access to the site and slope conditions do not pose a safety concern. I Another use of the blankets, particularly those made of 100% coconut fiber, is as a longitudinal buffer strip, installed along the contour of a slope to reduce sheet flow velocities, settle our soil I fines, and trap ash from overland flow. Sources I :Two sources for the 100% coconut fiber blanket are: Pacific Soil Stabilization 1004 East Cypress I Santa Maria, CA 93454 Tel: (805) 925-7737 Fax: (805) 922-3769 I : Drainage Products, Inc. 44 Via El Centro I Oceanside, CA 92054 Tel: (619) 757-7211 Fax: (619)757-7214 I Costs Installed costs for the coconut blanket are around $1.25 per square yard for labor and materials or over $6,000 per acre. I HSI2 Hydraulic Soil Sealing Description I SS6 is a supplemental erosion control practice that may be applied with or without seed. The practice is applied by hydraulic seeding methods and binds the soil surface, ash, seed and mulch together through the use of an acrylic copolymer. The mixture is applied on critical slopes, I around foundations, and on off-road sites with limited access to straw-blowing (DM5) equipment. Typically, the SS6 is a one-step process which includes the following components on a per acre I basis. I Woodward-Clyde W:\9651135F\EC01-D-RO0C1 1 -Mar-979651 135F\SOG 4-22 I I SECTIONF OUR Phase I Erosion and Sediment Control Plan 500 pounds of wood fiber mulch; 1,000 pounds of recycled paper mulch; Appropriate seed mixture (or no seed mixture); and 55 to 110 gallons of acrylic copolymer, depending on soil conditions. I Upon curing, usually within 24 hours, the mixture forms a crust on the surface which protects the soil and ash from erosion but also allows water to infiltrate. Over time, the crust biodegrades as I plants develop. Sources I Wood Fiber Mulch: Weyerhaeuser Company 7001 396th S.E. I Snoqualmie, WA 98065 Tel: (800) 443-9179 Fax:. (296) 888-7504 I Recycled Paper Mulch: United Fibers 4280 IA Street I : Benicia, CA 94510 Tel: (707) 745-9030 1 Central Fiber Corporation 4814 Fiber Lane Wellsville, KS 66092 I Tel: (800)654-6117 Fax: (913)883-4429 I Acrylic Copolymer: Environmental Soil Systems, Inc. 13234 Whistler Avenue : I Granada Hills, CA 91344 : Tel: (800)368-4115 I Fax: (818) 368-9393 Soil Seal 3015 Supply Avenue I Los Angeles, CA 90040 Tel: (213)727-0654 Fax: (213) 727-6037 I Costs : The costs for this practice, including labor and materials, range from $1,200 for low application rates of the copolymer to $1,900 for the higher application rates, without seed. Woodward-Clyde : W9651 1 35Eco1DR:Doc\1 Mar-951135F\SDG 4-23 I SECTIONF OUR Phase I Erosion and Sediment Control Plan 4.6 SCREEN AND SELECT BEST ALTERNATIVES (STEP 6) Based on discussions with the City regarding the selection criteria described above in Step 4, and the alternatives described above in Step 5, the mitigation measures for each-site were selected. As indicated in Table 2, some alternatives require interagency coordination or .interjurisdictional agreements before further action may be taken. The City will need to make decisions on whether or not to implement the suggested measures. However,'we',recommend the following prioritization based on potential adverse impacts. Priority 1 'Increase capacity of the Arizona crossing upstream detention area and unplug outlet pipe; replace the upstream inlet riser. Priority 2 Install gravel bag check dams within the Rancheros area. Priority 3 Raise bed of road crossing at the Arizona crossing. Priority 4 Remove sediment, vegetation, and debris from San Marcos Creek channel through golf course. Priority 5 Pump down lake level 5 to 6 feet in Lake San Marcos Priority 6 Construct temporary check dams within Box Canyon. The measures were ranked using the following criteria 1. Public health and safety 2 Damage to drainage infrastructure and sensitive receiving water bodies 3. 'Access Table 6 discusses the selection of preferred alternatives recommended by 'Woodward-Clyde for each candidate location and identifies the actions/decisions that have been taken .by the City to date. Woodward-Clyde W:9651 135F\ECO1-D-RDOC1 1-Mar-979651135F\SDG - 4-24 — — — — — — — — — —. — — — — — — — SECTIONFOUR Phase I Erosion and Sediment Control Plan Table 6 SELECTION OF PREFERRED ALTERNATIVES Location Action Cost Status Decision Lake San Marcos Pump down lake level 5 to 6 feet between Currently undetermined Curiently This is a preferred alternative; however, the winter storms to store water and sediment and discussing with dam is not a City-owned property. reduce downstream peak flows and sediment HOA and County Coordination with Lake San Marcos loads. S Association and County of San Diego is necessary. Box Canyon Temporary check dam structures constructed N/A Not feasible This alternative is deemed not practicable due within the canyon bottom. to the inaccessible nature of Box Canyon and the high potential for failure of the temporary structures during high peak flows. Rancheros Area Install gravel bag check dam structures within N/A Completed Performed under direction of City. the Rancheros area. Rancheros Area Apply soil stabilization measures to denuded N/A Not feasible This alternative is deemed not feasible due to slopes, large area where measures would be applied. Cost prohibitive. Arizona Crossing Increase the capacity of the upstream detention Completed Performed under direction of City. area; unplug the outlet pipe; replace the upstream outlet riser. Arizona Crossing Raise the bed of the road crossing the structure 9-inch gabion mattress Under Temporary roadbed enhancement structures and maintain capacity of upstream side. $10,000 to $12,000 (installed) consideration are under consideration relative to the frequency of sediment removal to determine Geogrid roadbed the most cost-effective and feasible $4,500 (installed) (additional cost for fill alternative material) Flex-block or Armorfiex $18,000 (installed) Resort of La Costa Remove sediment, vegetation, and debris from N/A In progress The resort has initiated removal of sediment, Golf Course San Marcos Creek channel through golf course. debris, and vegetation from the channel, and will do so on an on-going basis. Woodward-Clyde 0 W:',9651 1 35F\ECO1-D-R.00C\1 1-Mar-97',9651 135F\SOG 4-25 SECTIONFOUR Phase I Erosion and Sediment Control Plan 4.7 DEVELOP EROSION AND SEDIMENT CONTROL PLANS AND SPECIFICATIONS (STEP 7). Based on the screened and selected erosion and sediment control alternatives, plans and specifications were developed. These plans and specifications are provided in Appendix B. 4.7.1 Location Map Provided on Figure 3 is an erosion and sediment control measures Location Map. Shown on the map are color-coded areas for each of the selected control practices described in Table 6. 4.7.2 Details and Standard Specifications Provided in Appendix B are installation details and standard specifications for the selected practices. Also included in Appendix B are details and specifications for other practices not presently included in the Plan, but which the City may want to install on an as-needed basis. Modifications to the Plan may include installation of these additional measures and possibly others not currently identified. Modifications to the Plan will be provided as appropriate based on the performance of the installed measures and additional problems that may need to be addressed during the rainy season. 4.8 SCHEDULE AND IMPLEMENT THE PLAN (STEP 8) The initial installation of the gravel bag check dams and barriers was completed in November, 1996 with NCCC labor crews and CDF Corrections labor crews under the City's direction. Installation of the new measures requiring separate contractors (Arizona crossing and Lake San Marcos) will take approximately 2 weeks to complete, after contractor selection and notice-to- proceed. The pump-down of Lake San Marcos should be performed between significant storm events throughout the winter in order to maintain adequate storage capacity. 4.9 OPERATE AND MONITOR THE INSTALLED SYSTEMS (STEP 9) To provide for the continued performance of the installed mitigation measures, they must be operated and monitored throughout the rainy season. In particular, measures should be monitored before, during, and after storm events. Measures should be operated using the following guidelines: Gravel bag barriers should be cleaned of accumulated materials when the material is within 6 inches of the top of the barrier. If the City chooses not to clean out the accumulated sediment, then the barriers will become ineffective as sediment control devices. Check dams (gravel bag) should be cleaned when accumulated sediment reaches one-half the height of the check dam. If the City chooses not to clean out the accumulated sediment, then the barriers will become ineffective as sediment control devices. OOdWarcLClyde W:\9651135F\EC01-D-R.DOC\12-Mar-97\9651135F\SDG 4-26 I I I I I I I I U I Li I I LI I 1 I n I SECTIONF OUR Phase I Erosion and Sediment Control Plan I Inlet filters for storm drains should be cleaned when sediment covers the first course of I gravel bags. U • The detention basin upstream of the Arizona crossing should be cleaned of accumulated I sediment when the sediment is within one foot of the crest of the crossing. Erosion and sedimentation problems that occur during the rainy months or lack of-vegetative growth should be addressed on a case-by-case bases with remedial mitigation provided as I appropriate. I . 4.9.1 Storm Events The control measures recommended in this plan will not control all problems. Further, more intense storm events may result in problems that must be addressed to reduce property damage. I The most important step in controlling runoff damage from intense storm events following a major fire is pre-storm planning. This involves identifying potential problem areas, developing I emergency measures, and locating needed resources. Problem areas can include possible water and/or debris flows, storm drains subject to plugging, flooding, erosion, and sediment transport. These areas can be identified by field observation and consideration of problem areas that existed I prior to the fire. In specified areas, the Plan identifies some extensive control measures to reduce the impact of I problems resulting from more intense storms. However, additional control measures may be needed in these and other problem areas as identified during an evaluation of the performance of the mitigation measures during the winter storms. The problem areas should be documented and I control measures developed and implemented immediately. Contractors and suppliers of materials that may be needed should be identified ahead of time and after-hours contact numbers provided to emergency coordinators. Prior to a forecasted I precipitation event, materials and equipment that may be needed should be deployed to the vicinity of the potential problem areas. For example, backhoes should be placed in the vicinity I of major storm drains inlets that may become blocked. Communications are often disrupted during major storm events. The City's radio communica- tion system should be used to provide a reliable backup to telephone communications. I Appropriate City staff should be placed on-call during predicted storm events. To the extent possible, storm-related assignments should be made prior to the storm to minimize the amount of I organization effort required during the event. Also, rain gear and necessary equipment (shovels, flashlights, etc.) should be distributed prior to the storm event or be made readily available at convenient and known locations. I Following each storm, an assessment should be performed to evaluate the effectiveness of control measures and to identify additional measures needed to control problems resulting from i subsequent storms. I Woodward-Clyde W:9651135F\ECO1-D-R.DOC11-Mar-97\9651135FSDG 4-27 I - - Itb Ag /1 - 1 4 j\: I[AKE SAN MARCOS DA IN MJ - 5 - *1 IF rtJd A ci I no IF rp"sw NOW 04 w10 71 j - * N 1ióx CANYON - P' - i - - 4 ; LAGOON ESORTOFCOSTAGO CO ! LSANTMARCOS CRE(1 - , ' r - ARIZONA CROSSING WITH UPSTREAM ADJACENT DETENTION BASIN JF 7K -.. Et. CAMINO REAL BRIDGE] - Mt\r: UU /.0 MII'IU IC. CINLIINI I# /\I'4L) RANCHO SANTA FE QUADRANGLES LEGEND INDICATES APPROXIMATE LIMITS OF DRAINAGE AREAS INDICATES APPROXIMATE LIMITS OF BURN AREA ® INDICATES UNBURNED AREAS o 2000 4000 __j APPROXIMATE GRAPHIC SCALE (FEET) WOODWARD—CLYDE - - __P_•_-.__•_ * - - - - - - - - - - - - - - - - - HEC1 SIN: 1343001570 HMVersion: 6.33 Data File: Y:\SANDIEGO\PRE-BUR1.HC1 ******+* ************ *****44+********* **** + * FLOOD HYDROGRAPH PACKAGE (HEC-1) * + MAY 1991 * VERSION 4.0.1E * * * RUN DATE 11/26/1996 TIME 20:36:10 * * * * 4 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 4 * * * * * * * * 4 * U.S. ARMY CORPS OF ENGINEERS * * HYDROLOGIC ENGINEERING CENTER * * 609 SECOND STREET * DAVIS, CALIFORNIA 95616 * * (916) 756-1104 * *4* ******* *********+******************* x x. xxxxxxx 'xxxxx x x x x x x xx x x x x xxxxxxx xxxx x xxxxx x x x x x x x x ,x x x x x xxxxxxx xxxxx xxx Full Microcomputer Implementation by Haestad Methods, Inc. 37 Brookside Road * Waterbury, Connecticut 06708 * (203) 755-1666 THIS PROGRAM REPLACES ALL PREVIOUS VERSIONS OF HEC-1 KNOWN AS HEC1 (JAN 73), HEC1GS, HEC1DB, AND HEC1KW. THE DEFINITIONS OF VARIABLES -RTIMP- AND -RTIOR- HAVE CHANGED FROM THOSE USED WITH THE 1973-STYLE INPUT STRUCTURE. THE DEFINITION OF -AMSKK- ON RN-CARD WAS CHANGED WITH REVISIONS DATED 28 SEP 81. THIS IS THE FORTRAN77 VERSION NEW OPTIONS: DAMBREAK OUTFLOW SUBMERGENCE ; SINGLE EVENT DAMAGE CALCULATION, DSS:WRITE STAGE FREQUENCY, DSS:READ TIME SERIES AT DESIRED CALCULATION INTERVAL LOSS RATE:GREEN AND P.NPT INFILTRATION KINEMATIC WAVE: NEW FINITE DIFFERENCE ALGORITHM HEC-1 INPUT PAGE LINE ID . 1.2.•. 3.4.5..6.7. 8.•.9. 10 *DIAGRAM 1 ID 2 ID 3 ID . 4 ID * * 5 ID * WOODWARD-CLYDE CONSULTANTS * 6 ID * 7 ID 8 ID 9 ID 10 ID 11 ID CARLSBAD FIRESTORM 12 ID PRE-BURN 2 YEAR 6-HOUR STORM 13 ID FILE NAME: PRE-BUR1 NOVEMBER 26, 1996 14 ID ......1 .......2 ........3 .......4. ................6 .......7 .......8 .......9 ......10 15 . ID 16 IT 15 100 17 IN 8 18 10 * 0 19 XX LSM 20 PB 1.18 21 PC .009 .016 .025 .034 .045 .054 .065 .077 .090 .104 22 PC .120 .137 .157 .180 .210 .255 .322 .410 .506 .588 23 PC .629 .656 .679 .700 .720 .739 .756 .772 .790 .800 24 PC .816 .831 .845 .860 .872 .885 .895 .905 .914 .924 25 PC .935 .945 .954 .963 .972 .981 .991 1.000 26 BA 27.3 27 LS 0 81 28 UD * 1.86 29 . XX DAM 30 RS I ELEV 493 31 SA 5 59 59 59 32 SE 413 488 493 503 33 SS * 493 325 3.3 1.5 34 XX STRM1 35 RD * 18000 0.0228 0.04 TRAP 50 3 36 XX AZC 37 PB 1.18 38 BA 4.1 39 LS 0 63 N LI 0 PAGE 2 NEC-i INPUT ID.......1 .......2 ........3 .......4 .......5 .......6 .......7 ........8 .......9 ......10 KK BOX KM COMBINE RUNOFF FROM STRM1 AND AZC NC 2 * KK STRM2 RD 8500 0.0035 0.04 TRAP 600 10 * KK CcR PB 1.18 5 5 BA 6.8 LS 0 77 UD 1.26 * KK COMB1 . . KM COMBINE RUNOFF FROM ECR AND STRN2 NC . 2 KK ENC PB .89 BA 7.4 LS 0 81 UD 1.18 KK COMB2 . S KM COLLECTION POINT--COMBINE .HYDROGRAPHS FROM COMB1 AND ENC NC 2 zz LINE 41 42 43 454 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 RUNOFF SUMMARY OPERATION STATION HYDROGRAPH AT LSM ROUTED TO DAM ROUTED To STRM1 HYDROGRAPH AT AZC 2 COMBINED AT - BOX -ROUTED TO STRM2 HYDROGRAPH AT ECR 2 COMBINED AT COMB1 HYDROGRAPH AT ENC 2 COMBINED AT COM82 FLOW IN CUBIC FEET PER SECOND TIME IN HOURS, AREA IN SQUARE MILES PEAK TIME OF AVERAGE FLOW FOR MAXIMUM PERIOD BASIN MAXIMUM TIME OF FLOW PEAK - AREA - STAGE MAX STAGE - 6-HOUR 24-HOUR - 72-HOUR - 631. 600 - 449. 121. 118. 27.30 - 612. 6.75 429. 121. 118. 27.30 - - 493.68 6.75 611; - - 1.25 428. - 118. 27.30 - 0. - 7.00 - 0. 0. - - 0. - 4.10 -611. 7.25 - 428. -- 121. 118. 31.40 621. 7.50 421. - - 118. 31.40 - 104. 6.00 68. 17. 17. 6.80 688. 7.50 446. 140. - 135. 38.20 79. 6.00 50; - - 13. - 12. - 7.40 - - 735. 7.50 465. 152. 148. 45.60 - - - - - - - - - - - ,- - - - - - - - - SUMMARY OF KINEMATIC WAVE - MUSKINGUM-CUNGE ROUTING (FLOW IS DIRECT RUNOFF WITHOUT BASE FLOW) INTERPOLATED TO COMPUTATION INTERVAL ISTAQ ELEMENT DT PEAK TIME TO VOLUME DT PEAK TIME TO VOLUME 'PEAK PEAK (MIN) (CE'S) (MIN) ' (IN) (MIN) (CE'S) (MIN) (IN) STRM1 MANE 13.50 612.16 432.00 ' 0.17 1500 611.42 435.00 0.17 CONTINUITY SUMMARY (AC-FT) - INFLOW=0.2405E+03EXCESS=0.0000E+00 OUTFLOW=0.2408E+03 BASIN STORAGE=0.4899E+00 PERCENT ERROR= -0.3 STRM2 MANE 12.75 647.68 446.25 0.14 15.00 620.90 ' 450.00 0.14 CONTINUITY SUMMARY (AC-FT) - INFLOW=0.2406E+03 EXCESS=0.0000E+00 OUTFLOW=0.2419E+03 BASIN STORAGE=0.1838E+01 PERCENT ERROR= -1.3 - - - - - - - - - -. - - - - - - - -. NEC-i INPUT PAGE 1 LINE ID.......1 .......2 .......3 .......4 .......5. ......6 .......7 .......8. ......9 ......10 1 ID 2 ID 3 ID 4 ID *4*4* * ************************** *44*4* ** 5 ID 6 ID WOODWARD-CLYDE CONSULTANTS * 7 ID * * 8 ID *4* ***#**** *********************************** 9 ID 10 ID - 11 ID 12 ID CARLSBAD FIRESTORM 13 ID PRE-BURN 25 YEAR 6-HOUR STORM 14 ID FILE NAME: PRE-BUR1 NOVEMBER 26, 1996 15 ID .....1 .......2 .......3 .......4 .......5 .......6 .......7 ........8 .......9 ......10 16 ID 17 IT 15 100 18 IN 8 19 10 * '0 20 KK LSM 21 PB 2.80 22 PC .009 .016 .025 .034 .045 .054 .065 .077 .090 .104 .23 PC .120 .137 .157 .180 .210 . .255 .322 .410 .506 .588 24 . PC .629 .656 .679 .700 .720 .739 .756 .772 .790 .800 25 - PC .816 .831 .845 .860 .872 .885 .895 .905 .914 .924 26 PC .935 .945 .954 .963 .972 .981 .991 1.000 27 BA 27.3 28 LS 0 81 29 UD * 1.86 : .30 KK DAN 31 RS 1 ELEV 493 - 32 SA 5 .59 59 59 33 SE 413 488 493 503 34 SS * 493 325 3.3 1.5 35 KK STRN1 36 RD * 18000 0.0228 0.04 TRAP 50 3 37 1(1< AZC 38 PB 2.80 - 39 BA 4.1 40 LS 0 63 I I I I I 1 I I I I I I I I I II HI I mom mm — — — — — — — — — — — — — — — NEC-i INPUT PAGE 2 LINE ID.......1 .......2 .......3 .......4 .......5 .......6 .......7 .......8 .......9 ......10 42 KK BOX 43 KM COMBINE RUNOFF FROM STRM1 AND AZC 44 MC * 2 45 KK STRM2 46 RD * 8500 0.0035 0.04 TRAP 600 10 47 KK ECR 48 PB 2.80 49 BA 6.8 50 LS 0 71 51 UD * 1.26 ° 52 KK COMB1 53 KM COMBINE RUNOFF FROM ECR AND STRM2 54 HC * 2 55 KK ENC 56 PB 2.10 57 BA 7.4 58 LS 0 81 59 UD 1.18 60 KK COMB2 61 -KM COLLECTION POINT--COMBINE HYDROGRAPHS FROM COMBI AND ENC 62 HC 2 ° 63 ZZ - - - - - - - - - - - - - - - - - - - RUNOFF SUMMARY FLOW IN CUBIC FEET PER SECOND • TIME IN HOURS, AREA IN SQUARE MILES PEAK TIME OF AVERAGE FLOW FOR MAXIMUM PERIOD BASIN MAXIMUM TIME OF OPERATION STATION FLOW PEAK : AREA STAGE MAX STAGE • S 6-HOUR 24-HOUR 72-HOUR HYDROGRAPH AT LSM 4684. 5.00 3159. 853. 827. 27.30 •• ROUTED TO • DAM 4608. 5.25 3105. 853. 827. 27.30 / • 495.64 5.25 • • ROUTED. TO • . STRM1 4596. 5.50 3100. 853. 827. 27.30 HYDROGRAPH AT S . S AZC 233. 4.75 154. • 39. 38. 4.10 2 COMBINED AT - BOX 4816. 5.50 '3232. :892. 865. 31.40 ROUTED TO S STRM2 4790. 5.75 3213. 893. 866. 31.40 HYDROGRAPH AT • S • S • S • S ECR 1088. 4.00 663. 171. 166. 6.80 5 2 COMBINED AT S COMB1 5577. 5.75 3667. 1064. 1032. 38.20 5 5 S HYDROGRAPH AT . S S ENC 868. 4.00 519. 133. 129; 7.40 • S S S 2 COMBINED AT COMB2 6184. 5.75 4074. 1197. 1161. • 45.60 • • S - - - - - - - - - -. - - - - - - - - SUMMARY OF KINEMATIC WAVE - MUSKINGUM-CUNGE ROUTING (FLOW IS DIRECT RUNOFF WITHOUT BASE FLOW) INTERPOLATED TO COMPUTATION INTERVAL ISTAQ ELEMENT DT PEAK TIME TO VOLUME DT PEAK TIME TO VOLUME PEAK PEAK (MIN) (CFS) (MIN) (IN) (MIN) (CFS) (MIN) (IN) STRI'11 MANE 11.25 4611.64 326.25 1.16 15.00 4595.86 330.00 1.16 CONTINUITY SUMMARY (AC-FT) - INFLOW=0.1691E+04 EXCESS=0.0000E+00 OUTFLOW=0.1692E+04 BASIN STORAGE=0.5934E+00 PERCENT ERROR= -0.1 STRN2 MANE 12.00 4803.84 348.00 1.06 15.00 4790.32 345.00 1.06 CONTINUITY SUMMARY (AC-FT) - INFLOWO 1769E+04 EXCESS=O 0000E+00 OUTFLOW=0 1771E+04 BASIN STORAGE=0 1844E1-01 PERCENT ERROR -0.2 - - - - - - - - - - - - - - - -. - - NEC-1 INPUT PAGE 1 LINE ID ........ l ....... 2.3.4.5.6.7.8.9.10 1 ID 2 ID 3 ID * *4*4*44*4*4*4* ******************************* 4 ID * 4 5 . ID * W000WARD-CLYDE CONSULTANTS * 6 - ID * * 7 ID 4*4* ****************************************** 8 ID 9 ID 10 ID 11 ID CARLSBAD FIRESTORM 12 ID PR-BURN50 YEAR 6-HOUR STORM -13 ID FILE NAME: PRE-BUR1 NOVEMBER 26, 1996 14 ID .....1 .......2 ........3 .......4........5 ......-.6 .........7 .......8 .......9 ......10 15 ID 16 IT 15 100 17 IN 8 18 10 * 0 19 KM LSM 20 PB 3.21 - 21 PC .009 .016 .025 '.034 .045 .054 .065 .077 .090 .104 22 PC .120 .137 .157 .180 .210 .255 .322 .410 .506 .588 23 PC .629 .656 .679 - .700 .720 .739 .756 .772 .790 .800 24 PC .816 .831 .845 .860 .872 .885 .895 .905 .914 .924 25 PC .935 .945 .954. .963 .972 .981 .991 1.000 26 BA 27.3 - 27 LS 0 81 - 28. . UD 4 1.86 • - 29 KM DAN . 30 RS 1 ELEV 493 31 SA 5 59 59 59 32 SE 413 488 493 503 33 SS * 493 325 3.3 1.5 - 34 KM STRM1 35 - RD * 18000 0.0228 0.04 TRAP 50 • 3 36 KM AZC - 37 PB 3.21 38 BA 4.1 39 - LS 0 63 . 40 UD 0.89 . HEC-1 INPUT PAGE 2 LINE ID ....... .1 ........2 .......3 .......4 ........5 .......6 .......7 .......8 .......9 ......10 41 KK BOX - 42 KM COMBINE RUNOFF FROM STRM1 AND AZC 43 NC 2 44 KK STRM2 45 RD * 800 0.0035 0.04 TRAP 600 10 46 KK ECR 47 PS 3.21 48 BA. 6.8 49 LS 0 77 : 50 UD 1.26 51 KK COMB1 52 ' • KM COMBINE RUNOFF FROM ECR AND STRM2 53 NC 2 54 - KK ENC • • • 55 1 PB 2.41 • • 56 BA 7.4 • 57 LS 0 81 58 • UD 1.18 • •. 59 KK COM82 • • 60 KM COLLECTION POINT--COMBINE HYDROGRAPHS FROM COMB1 AND ENC 61 • HC 2 .- • 62 ZZ • • • • • : • • RUNOFF SUMMARY FLOW IN CUBIC FEET PER SECOND TIME IN HOURS, AREA IN SQUARE MILES PEAK TIME OF AVERAGE FLOW FOR MAXIMUM PERIOD BASIN MAXIMUM TIME OF OPERATION STATION FLOW PEAK AREA - STAGE MAX STAGE 6-HOUR 24-HOUR 72-HOUR HYDROGRAPH AT LSM 6038. 4.75 4016. 1084. 1051. 27.30 ROUTED TO DAM 5936. 5.00 3956. 1084. 1051. 27.30 496.13 5.00 -ROUTED TO srRM1 5921. 5.25 3950. 1084. 1051. 27.30 HYDROGRAPH AT AZC 356. 4.00 229. 58. 56. 4.10 2 COMBINED AT - BOX 6242. 5.25 4139. 1142. 1107. 31.40 ROUTED TO STRM2 6203. 5.75 4122. 1142. 1108. 31.40 HYDROGRAPH AT ECR 1461. 4.00 865. 223. 216. 6.80 2 COMBINED AT COMB1 7232. 5.50 4745. 1365. 1324. 38.20 HYDROGRAPH AT ENC 1172. 4.00 682. 175. 170. 7.40 2 COMBINED AT S S COMB2 8053. 5.50 5310. 1540. 1493. 45.60 - - - - - - - - - - - - - - - - - - - SUMMARY OF KINEMATIC WAVE - MUSKINGUM-CUNGE ROUTING (FLOW IS DIRECT RUNOFF WITHOUT BASE FLOW) INTERPOLATED TO COMPUTATION INTERVAL ISTAQ ELEMENT DT PEAK TIME TO VOLUME DT PEAK TIME TO VOLUME PEAK PEAK (WIN) (CFS) (WIN) (IN) (MIN) )CFS) (WIN) (IN) STRM1 MANE ' 10.50 5920.92 315.00 1.48 15.00 5920.92 315.00 1.48 CONTINUITY SUMMARY (AC-ET) - INFLOW=0.2150E+04 EXCESS=O.0000E+00 OUTFLOW=0.2151E+04.BASIN STORAGE=0.6149E+00 PERCENT ERROR= -0.1 STRM2 MANE" 12.00 6222.24 336.00 1.35' 15.00 6202.66 345.00 ' 1:35 CONTINUITY SUMMARY (AC-FT) - INFLOW0.22655+04 EXCESSO.0000E+00; OUTFLOM0.2266E+04 BASIN STORAGE0.1835E101 PERCENT ERROR -0.1 - -S - - - - - - - - - - - - - - - - HEC-1 INPUT PAGE LINE ID . 1.2.3.4.5•. 6.7..:... .8.9.10 1 ID 2 ID 3 ID * * 4 ID WOODWARD-CLYDE CONSULTANTS 5 ID 6 ID 7 ' ID 8 ID ' 9 ID 10 - ID CARLSBAD FIRESTORM 11 ID PRE-BURN. 100 YEAR 6-HOUR STORM 12 ID , , FILE NAMED PRE-BUR1 NOVEMBER 26, 1996 13 ID .....1 ........2 ........3 .......4 .......5 .......6 .......7 ........8 .......9 ......10- '14 ID' 15 IT 15 100 16 IN '8 17 IC- * 0 - 18 KK LSM 19 - PS 3.61 - 20 PC .009 .016 .025 .034 .045 .054 - .065 .077 .090 .104 - 21 - PC .120 .137 .157 .180 .210 .255 .322 .410 .506 .588 - 22 PC .629 .656 .679 .700 .720 .739 .756 .772 .790 .800 23 PC .816 .831 .845 .860 .872 .885 .895 .905 .914 ;924 24 PC .935 .945 .954 .963 .972 .981 .991 1.000 25' - BA 27.3 26 LS 0 81 27 - UD .1.86 28-' KK DPI1 29 RS 1 ELEV 493 5 30 ' SA 5 59 59 59 31 SE 413 .488 493 503 32 '. SS * 493 325 3.3 1.5 - - 33 KK STRM1 34 RD * 18000 0.0228 0.04 TRAP 50 3 35 KR AZC 36 'PB 3.61 - - 37 BA 4.1 5 ' 38 - 'LS 0 63 39 UD * 0.89 - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - NEC-i INPUT 0 PAGE 2 LINE ID 1 2 3 4 5 6 7 8 9 10 43 KK STRM2 . . 44 RD. * 8500 0.0035 0.04 TRAP 600 10 . . 45 KK ECR . 46 PB 3.61 47 BA 6.8 0 48 LS 0 77 . . . 49 UD * 1.26 - 0 0 0 . 50. . KK COMB1 0 0• 51 KM COMBINE RUNOFF FROM ECR AND STRM2 52 - HC * 2 0 0 0 53 10< ENC 54 PB 2.71 55 BA .7.4 0 0 56. LS. 0 81 0 0 57 0 UD * 0 1.18 - 0 0 58 KK CONB2 0 0 59 . KM COLLECTION POINT--COMBINE HYDROGRAPHS FROM COMB1 AND ENC 0 60 NC 2- 0 0 61 ZZ 0 0 0 0 RUNOFF SUMMARY FLOW IN CUBIC FEET PER SECOND TIME IN HOURS, AREA IN SQUARE MILES PEAK TIME OF AVERAGE FLOW FOR MAXIMUM PERIOD BASIN MAXIMUM TIME OF OPERATION STATION FLOW PEAK AREA STAGE MAX STAGE 6-HOUR 24-HOUR 72-HOUR HYDROGRAPH AT LSM 7427. 4.75 4888. 1320: 1280. 27.30 ROUTED TO DAM 7321. 5.00 4827. 1320. 1280. 27.30 496.59 5.00 ROUTED TO STRM1 7298. 5.25 4813. 1321. 1281. 27.30 HYDROGRAPH AT AZC 511. 3.75 311. 79.. 76. 4.10 - 2 COMBINED AT BOX 771. 5.25 5082. 1400. - 1357. 31.40 ROUTED TO STRM2 7675. 5.50 5051. . 1401. 1358: 31.40 HYDROGRAPH AT ECR 1851. 4.00 1074. 277. 268. 6.80 2 COMBINED AT COMB1 8961. 5.50 5857. 1677. 1627. 38.20 HYDROGRAPH AT ENC 1487. 4.00 850. - 218. 211. 7.40 2 COMBINED AT COMB2 9960. 5.50 6572. 1895. - 1838. 45.60 - - - - - - -: - - - - - - - - - - - - SUMMARY OF KINEMATIC WAVE - MUSKINGUM-CUNGE ROUTING - (FLOW IS DIRECT RUNOFF WITHOUT BASE FLOW) INTERPOLATED TO COMPUTATION INTERVAL ISTAQ ELEMENT DT PEAK TIME TO VOLUME DT PEAK TIME TO VOLUME PEAK PEAK (Mir ') (CFS) )MIN) (IN) (MIN) (CFS) (MIN) (IN) STRM1 MANE 11.25 7297.92 315.00 1.80 - 15.00 7297.92 315.00 1.80 CONTINUITY SUMMARY )AC-FT) - INFLOW=O.2618E+04 EXCESS=0.0000E+00 OUTFLOW=0.2619E+04 BASIN STORAGE=0.6259E+00 PERCENT ERROR -0.1 STRM2 MANE 12.75 7687.93 331.50 1.66 15.00 7674.55 330.00 1.66 CONTINUITY SUMMARY (AC-FT) -INFLOW=0.277E+04 EXCESS=0.0000Ef00 OUTFLOW=02779E+04 BASIN STORAGE=0.1890E+01 PERCENT ERROR -0.1 NORMAL END OF HEC-1 HEC1 SIN: 1343001570 HMVersion: 6.33 Data File: Y:\SANDIEGO\POS-BUR1.HC1 * FLOOD HYDROGRAPH PACKAGE (HEC-1) * . *U.S. ARMY CORPS OF ENGINEERS * MAY 1991 . * . * HYDROLOGIC ENGINEERING. CENTER - * VERSION 4.0.1E. * * 609 SECOND STREET * DAVIS, CALIFORNIA 95616- . * RUN DATE 11/26/1996 TIME 20:36:41 . * (916) 756-1104 * x x xxxxxxx xxxxx x x x x x xx- x x x x xxxxxxx xxxx x xxxxx x x x x x x x-x x. x x x x xxxxxxx xxxxx xxx - - Full Microcomputer Implementation by Haestad Methods, Inc. : 37 Brookside Road Waterbury, Connecticut 06708* (203) 755-1666 THIS PROGRAM REPLACES ALL PREVIOUS VERSIONS OF HEC-1 KNOWN AS HEC1 (JAN 73), HEC1GS, HEC1DB, AND HEC1KW - - THE DEFINITIONS OF VARIABLES -RTIMP- AND -RTIOR- HAVE CHANGED FROM THOSE USED WITH THE 1973-STY.E INPUT STRUCTURE THE DEFINITION OF -ANSKK- ON RN-CARD WAS CHANGED WITH REVISIONS DATED 28 SEP 81. THIS IS THE EORTRAN77 VERSION NEW OPTIONS DAMBREAX OUTFLOW SUBMERGENCE SINGLE EVENT DAMAGE CALCULATION DSS WRITE STAGE FREQUENCY DSS:READ TIME SERIES AT DESIRED CALCULATION INTERVAL LOSS RATE:GREEN AND AMPT INFILTRATION - KINEMATIC WAVE: NEW FINITE DIFFERENCE.ALGORITHM • - - - - - - - - - - - - - - - .- - - NEC-i INPUT PAGE 'LINE ID ........ 1 ....... 2 . 3 .4 .5 .6 .7 .8 .9 .10 *DIAGRAM 1 ID 2 ID ' * 3 ID - 4. , ID 5 ID , , WOODWARD-CLYDE CONSULTANTS 6 'ID 7 8 ID ' 9 ID 10 ' ID 11 , ID ' CARLSBAD FIRESTORM 12 ID POS-BURN 2 YEAR 6-HOUR STORM 13 ID ' FILE NAME: POS-BURi NOVEMBER 26, 1996 14 ID .....1 .......2 .......3 .......4 .......5 .......6 .......7 .......8 .......9 ......10 15 ID 16' IT 15 ' 100 17 IN 8 18 , 10 0 19 KK LSM 20 PB 1.18 21 PC .009 .016 .025 .034 .045 .054 .065 .077 .090 .104 22 PC .120 .137 .157 .180 .210 .255 .322 .410 .506 .588 23 PC .629 .656 .679 .700 .720 .739 .756 .772 .790 .800 24 * PC .816 .831 .845 * .860 .872 .885 .895 .905 .914 .924 25 PC .935 * .945 .954 .963 .972 .981 .991 1.000 26 BA 27.3 ' 27 LS 0 82 28 LID 1.86 29 KK DAM 30 RS 1 ELEV 493 31 SA 5 59 59 59 32 SE 413 488 493 503 33 SS 493 325 3.3 1.5 34 KK STRM1 35 RD 18000 0.0228 0.04 * TRAP 50 3 36 KK AZC ' • * ' * 37 PB 1.18 38 BA 4.1 39 'LS 0 73 I I H I I .: .: .' I H.., i. ''1 I 1 0 'S I S S 1 1•• I . I S. H 1 S S .: S Si S S 55 SS I I . I 0 .5 i s . ;': .5 .. S S 55 I S•.S S ... S.... S, I - - -MI.-M MON. - - HEC-1 INPUT PAGE 2 LINE ID ....... 1 .......2 .......3 .......4 ........5 .......6. ......7 .......8 .......9 ......10 41. KK BOX 42 . KM COMBINE RUNOFF FROM STRM1 AND AZC 43 • HC .* 2 . 44 .KK STRM2 . 45 RD * 8500 0.0035 0.04 TRAP 600 10 • 46 KK ECR 47 PB 1.18 48 BA 6.8 49 LS 0 77 50 UD 1.26 51 KK-COMB1 52 KM COMBINE RUNOFF FROM ECS AND STRM2 • 53 : HC 2 • • 54. KK ENC • . . 55 PB .89 . 56 BA 7.4 • 57 LS 0 85 . S 58 • UD 1.18 . • • S • • S 59 KK COMB2 S S 60 KM COLLECTION POINT--COMBINE I-1YDROGRAPHS FROM COMB1 AND ENC 61 NC 2 62 ZZ S . -.- - -.-. - - -, - - - - - -.- -.- .- -. RUNOFF SUMMARY FLOW IN CUBIC FEET PER SECOND TIME IN HOURS, AREA IN SQUARE MILES PEAK TIME OF AVERAGE FLOW FOR MAXIMUM PERIOD BASIN MAXIMUM TIME OF OPERATION STATION FLOW PEAK . AREA STAGE MAX STAGE • 6-HOUR 24-HOUR 72-HOUR HYDROGRAPH AT LSM 709 5 75 508 137 133.'27 30 ROUTED TO DAM 686. 6.50 486. 137. 133. 27.30. 493.74 6.50 ROUTED TO • . STRM1 687. 7.00 484. 137. 133. 27.30 HYDROGRAPH AT AZC 38. 6.25 21. 5. 5. 4.10 2 COMBINED. AT • • BOX 717. 6.75 501. 142. 138. 31.40 ROUTED TO STRM2 754 7 25 495 143 139 31 40 HYDROGRAPH AT . . S •• S • . .. ECR 104. 6.00 68. 17. 17. 6.80 2-COMBINED AT . S COMB1 835. 7.25 . 525. 160. 156. 38.20 HYDROGRAPH AT . S ENC 143. 5.00 . 97. 25. 24. 7.40 2 COMBINED AT • S S S COMB2 . 931. 6.75 562. 185. 180. 45.60 • S SUMMARY OF KINEMATIC WAVE - MUSKINGUM-CUNGE ROUTING (FLOW IS DIRECT RUNOFF WITHOUT BASE FLOW) S INTERPOLATED TO 5' COMPUTATION INTERVAL ISTAQ ELEMENT DT PEAK TIME TO VOLUME DT PEAK TIME' TO VOLUME - S SPEAK ' PEAK • - (MIN) • , (CFS) • (MIN) (IN) • (MIN) (CFS) (MIN) • (IN)' - S • • - 0' , , • • STRM1 MANE 13.50 686.96 418.50 • 0.19 • 15.00 686.66 420.00 0.19 - CONTINUITY SUMMARY (AC-ET) - INFLOW=0.272,1E+03,EXCESS=0.0000E+00 OUTFLOW=0.2724E+03 BASIN STORAGE=0.4965E+00 PERCENT ERROR= -0.3 - - STRM2 MANE 15.00 754.12 435.00 0.17 15.00 754.12 435.00 0.17 CONTINUITY SUMMARY (AC-FT) - INFLOW=0.2824E+03 EXCESS=O.0000E+00 OUTFLOW=0.2837E+03 BASIN STORAGE=0.1825E+01 PERCENT ERROR -1.1 - .- - - -5- - - 5- - - - no - No, No. ON - - PAGE 1 NEC-i INPUT LINE ID .1.2.3.4.5.6.7.8.9.10 1 ID 2 ID 3 ID 4 ID - 5 ID 6 ID .- ' S WOODWARD-CLYDE CONSULTANTS ' * 7 ID- 8 ID 9- ID 10 ID 11 ID S 12 ID CARLSBAD FIRESTORM 13 ID POS-BURN 25 YEAR 6-HOUR STORM 14 ID FILE NAME: POS-BUR1 NOVEMBER 26, 1996 15 ID .....1 .......2 .......3 .......4 .......5 .......6 .......7 .......'8 .......9 ......10 16 ID 17 IT 15 ' 100 18 IN 8 5 19 10 * 0 20 KK --LSM. 21 PB 2.80 22 - PC .009 .016 .025 .034 - .045 .054 .065 .077 .090 .104 23 PC .120 .137 .157 .180 " .210 .255 .322 - .410 .506 ' .588 24 PC - .629 .656 .679 .700 .720 .739 .756 .772 .790 .800 25 Pc .816 .831 .845 .860 .872 .885 - .895 .905 .914 .924 26 ' - PC .935 .945 .954 .963 '.972 .981 .991 - 1.000 - 27 ' ' BA 27.3 28 LS 0 82 29 UD * 1.86 5 5 5 30 KK - DAM 31 RS 1 ELEVS 493 . 32 SA 5 59 - 59 59 33 SE 413 488 493 503' 34 ' SS '* 493 325 3.3 - 1.5 35 - KK 'STRMi - 36 - RD 18000 0.0228 0.04 TRAP ' -50 3 37 KK AZC 38 PB 2.80 5 5 39 BA 4.1 - 40 - LS 0 73 5 1 0 : 0• I' 1 I 1 000 0 01 0••• H 01• 0 0• 0• 0• I I I 0• 0 0• 10 1 0 - - 'I 00 :- I. S 0 - S I. :- '1 1•- 0 - -. - ,- .- - . '- -. - - - - - - •.,. a a - HEC-1 INPUT PAGE 2 LINE ID ........ 1 ........ 2 ........3 .......4 .......5 .......6 .......7 .......8 .......9 ......10 42 KK BOX 43 KM. COMBINE RUNOFF FROM STRM1 AND AZC 44 . HC - * 2 . . -45 KK STRM2 . . . . 46 • RD . * 8500 0.Ô035 0.04 TRAP 600 10 . 47 KK ECR . 48 PB 2.80 49 BA 6.8 50 LS 0- 77 . 51 UD * 1.26 52 - KK COMB1 - - - - 53 KM - COMBINE RUNOFF FROM ECR AND STRM2 54 HC * 2 55 KK - ENC 56 -PB 2.10 57 BA 7.4 58 LS 0 85 - - - 59 UD 1.18 60 KK- COMB2 S 61 - KM COLLECTION POINT--COMBINE HYDROGRAPHS FROM COMB1 AND ENC S 62 NC 2 5 5 5 5 63 ZZ - - - - -- - - - - - -- ,-- - - - RUNOFF SUMMARY FLOW IN CUBIC FEET PER SECOND TIME IN HOURS, AREA IN SQUARE MILES PEAK TIME OF AVERAGE FLOW FOR MAXIMUM PERIOD BASIN MAXIMUM TIME OF OPERATION STATION FLOW PEAK AREA STAGE MAX STAGE 6-HOUR 24-HOUR 72-HOUR HYDROGRAPH AT LSM 4966. 4.75 3327. 898. 871. .27.30 ROUTED TO S DAM 4876. 5.25 . 3270. 898. 871. 27.30 495.74 5.25 ROUTED TO STRN1 4860. 5.50 3267. 898. 871. 27.30 HYDROGRAPH AT AZC 568. 3.75 321. 81. 79. 4.10 2 COMBINED AT . BOX 5264. 5.25 3511. 980. 950. 31.40 ROUTED TO . STRN2 5251. 5.75 3503. 981. 951. 31.40 HYDROGRAPH AT . . ECR 1088. 4.00 663. 171. 166. 6.80 2 COMBINED AT . . . . COMB1 6038, 5.75 3991. 1152. 1117. 38.20 HYDROGRAPH AT . . . ENC 1185. 4.00 674. 173. 168. 7.40 2 COMBINED AT .. COMB2 6787. 5.50 4534. 1325. 1285. 45.60 - - - - - - - - - '- - - - - - on No - SUMMARY OF KINEMATIC WAVE - MUSKINGUM-CUNGE ROUTING, (FLOW IS DIRECT RUNOFF WITHOUT BASE FLOW) INTERPOLATED TO - COMPUTATION INTERVAL ISTAQ ELEMENT DT PEAK TIME TO VOLUME D'1 PEAK TIME TO VOLUME PEAK PEAK (WIN) (CES) (WIN) (IN) (MIN) (CES) (WIN) (TN) STRM1 MANE 11.25 4880 98 326.25 1.22 15.00 4859.90 330.00 1.22 CONTINUITY SUMMARY (AC-FT) - INFLOW=0.1781E+04 EXCESS=0.0000Ei-00 OUTFLOW=0.1782+04 BASIN STORAGE=0'.5959E+00 PERCENT ERROR= -0:1 STRM2 MANE' 11.25 5254.70 348.75 1.16 15.00 5251.23 345.00 1.16 CONTINUITY SUMMARY (AC-FT( - INFLOW=0 1943E+04 EXCESS=0 0000E+0O OUTE'LOW=O 1945E+04 BASIN STORAGE=0 1795E+01 PERCENT ERROR= -0.2 - - - - - - - - - - - - - - - - - - PAGE 1 HEC-1 INPUT LINE ID. 1.2.3.4.5.6.7 .8.9.10 1 ID 2 ID 3 ID *********************** 4 ID * * 5 ID WOODWARD-CLYDE CONSULTANTS * 6 ID * * 7 - ID 8 ' ID 9 ID 10 ''ID 11 ID CARLSBAD FIRESTORM 12 ' ID POS-BURN 50 YEAR 6-HOUR STORM 13 -ID FILE WANE: POS-BUR1 NOVEMBER 26, 1996 14 ID .....1 ................3 .......4 .......5 .......6 .......7 .......8 .......9 ......10 15 ID 16 IT 15 100 17 - IN 8 18 10 0 19 .. KK LSM .•. 20 PB 3.21 . 21 . PC .009 .016 .025 .034 .045 .054 .065' .077 .090' .104 22 PC .120 .137 .157 .180 .210 .255 .322 .410 .506 .588 23 ' PC . .629 .656 .679 .700 .720 .739 .756 .772 .790 .800 24 PC .816 .831 .845 .860 .872 .885 .895 .905 .914 .924 25 PC .935 .945 .954 .963 .972 .981 • .991 • 1.000 26 , BA' 27.3 • 27, LS 0 82 28 UD * 1.86 29 KK' DAN ' 30 RS 1 ELEV 493' 31 SA 5 59 59 59 32 SE 413 488 493 503 33 SS * 493 325 3.3 1.5 34 KK STRM1 • 35 RD 18000 0.0228 0.04 TRAP 50 . 3 • 36 KK AZC -, 37 - - PB 3.21 38 BA .4 .1 39 LS 0 73 40 UD 0.89 — — — — — — — — — — — — —on,— — got — — HEC-1 INPUT PAGE 2 LINE ID ........ 1 .......2 .......3 .4 .......5.......6 .......7 .......8 .....9 .....10 41 KK BOX . 42 KM COMBINE RUNOFF FROM STRM1 AND AZC . 43 * MC 44 KK STRM2 4,5 RD * . .8500 :0.0035 0.04 . . TRAP 600 .......... . 10 . ., . .. . . 46 KK ECR 47 PB 3.21 . . . . . 48 BA 6.8 . . 49 LS 0 77 . .. . . 50 LiD 1.26 . 51 KK COMB1 . . . . . 52 KM COMBINE RUNOFF FROM ECR AND STRN2 . . . . . . . 53 HC 2 . . . ...,. .. . . . 54 :. KK ENC . . . . ... . . 55 PB 2.41 • . . . . 0 0 0 0 0 . .56 . BA 7.4 5 . LS .0 85 • 0 0 58 • LiD 1.18 . •0 • 0 .. •. 0 •• 0 0 0 • • 59 KK COMB2 • 0 • 0 0 0 • 0 • 0 60 KM . COLLECTION POINT--COMBINE HYDROGRAPHS FROM COMB1 AND ENC 0 61 HC. 2 . 62 ZZ 0 0 - - - - - - - - - - - - - - - - - - - RUNOFF SUMMARY S FLOW IN CUBIC FEET PER SECOND TIME IN HOURS, AREA IN SQUARE MILES PEAK TIME OF AVERAGE FLOW FOR MAXIMUM PERIOD BASIN MAXIMUM TIME OF OPERATION STATION FLOW PEAK AREA STAGE MAX STAGE 6-HOUR 24-HOUR 72-HOUR HYDROGRAPH AT LSM 6359. 4.75 4204. 1135. 1101. 27.30 ROUTED TO ..... . . - DAM 6262. 500 4145. 1135. 1100. 27.30 496.24 5.00 ROUTED TO STRM1 6243. 5.25 4135. 1135. 1100. 27.30 HYDROGRAPH AT AZC 794. 3.50 431. 109. 106. 4.10 2 COMBINED AT . BOX 6766. 5.25 4475. 1244. 1206. 31.40 ROUTED TO - STRM2 6725. 5.50 4451. 1244. 1207. 31.40 HYDROGRAPH AT • .. ECR 1461.. 4.00 865. 223. 216. 6.80 5 ?*COMBINED AT . • COMB1 7784. 5.50 . 5121. 1467. 1423. 38.20 5 HYDROGRAPH AT . ENC 1544. 3.75 859. 220. 214. 7.40 2 COMBINED AT • . 5 S COMB2 8762. 5.50 5840. 1688. 1636. 45.60 5 5 5 - - - - - - - - - - - - - I- - - - - - - SUMMARY OF KINEMATIC WAVE - MUSKINGUM-CUNGE ROUTING (FLOW IS DIRECT RUNOFF WITHOUT BASE FLOW) INTERPOLATED TO COMPUTATION INTERVAL ISTAQ ELEMENT DT PEAK TIME TO VOLUME DT PEAK TIME TO VOLUME PEAK PEAK (MIN) (CFS) (WIN) (IN) (WIN) (CFS) (WIN) (IN) STRM1 MANE 10.50 6242.68 315.00 1.55 15 00 6242.68 31S.00 1 55 CONTINUITY SUMMARY (AC-FT) - INELOW=C 2251E+04 EXCESS=0 0000E+00 OUTE'LOW=O 2252E+04 BASIN STORAGE=O 6174E+0O PERCENT ERROR= -:0.1 STRM2 MANE 12.00 6751.58 336.00 1.47 15.00 6724.61 330.00 1.A7 CONTINUITY SUMMARY (AC-FT) - INFLOW=0 2468E+04 EXCESS=O 0000E+00 OUTE'LOW=O 2470E1-04 BASIN STORAGE=0 1842E+01 PERCENT ERROR= -0.2 . - - - - - - - - - - - - - - - - - - - PAGE 1 HEC-1 INPUT ID....... 1 ....... 2 ....... 3 ....... 4 ....... 5 ....... 6 ....... 7 ....... 8 ....... 9 ...... 10 ID ID ID * . •• * ID * WOODWARD-CLYDE CONSULTANTS + ID ID . . ID ID ID . ID . CARLSBAD FIRESTORM ID POS-BURN 100 YEAR 6-HOUR STORM ID FILE NAME: P05-BUR1 NOVEMBER 26, 1996 ID .....1 .......2 .......3 ........4 ........5 .......6 .......7 .......8 ....... 9 ....... 10 ID IT 15 100 IN 8 10 0 KK LSM . PB 3.61 . . PC .009 .016 .025 .034 .045 .054 - .065 .077 • .090 .104 PC .120 • .137 .157 .180 .210 .255 .322 .410 .506 .. .588 PC .629 .656 .679 .700 .720 .739 .756 .772 • .790 .800 PC .816 • .831 • .845 .860 .872 .885 .895 .905 .914 .924 PC..935 • .945 .954 .963 .972 .981 .991 • 1.000 BA 27.3 LS .0 82 UD 1.86 * KK DAM * • • RS •. 1 ELEV 493 SA 5 59 59 59 SE 413 488 493 503 SS 493 • 325 3.3 1.5 KK STRM1 RD 18000 .0.0228 0.04 • TRAP 50 3 * KK AZC- • . • PB 3.61 • BA 4.1 * LS -0 73 • :- • UD 0.89 LINE 1 2 3 4 5 6 .7 8 9 . 10 * 11 12 13 14 15 16 17 18 1:9 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 3*7 38 39 'HEC-1 INPUT PAGE 2 LINE ID....... 1 .......2 .......3 .......4 ........5 .......6 .......7 .......8 .......9 ......10 43 KK STRM2 44 RD 8500 0.0035 0.04 TRAP 600 10 45 KK ECR 46 'PB 3.61: 47 BA 6.8 , . 48. LS. 0 77 . 49 UD * 1.26 . . 50 KK ' COMB1 51 KM COMBINE RUNOFF FROM ECR AND STRM2 52 HC 53 KK ENC . 54 P8 2.71 55 BA 7.4 56 LS 0 85. 57 UD * 1.18 ' 58 KK COM82 59 KM COLLECTION POINT--COMBINE HYDROGRAPI4S FROM.COMB1 AND ENC 60 HC ' ' 2 61.' ZZ - - - - - - - - - - - - - - - - - - - RUNOFF SUMMARY FLOW IN CUBIC FEET PER SECOND TIME IN HOURS, AREA IN SQUARE MILES 0 PEAK TIME OF AVERAGE FLOW FOR MAXIMUM PERIOD BASIN MAXIMUM TIME OF OPERATION STATION FLOW PEAK AREA STAGE MAX STAGE 6-HOUR 24-HOUR 72-HOUR HYDROGRAPH AT LSM 7778. 4.75 5093. 1376. 1334. 27.30 ROUTED TO DAM 7668. 5.00 5033. 1375. 1334. . 27.30 496.71 5.00 ROUTED TO 0 STRM1 7639. 5.25 5020. 1377. 1335. 27.30 HYDROGRAPH AT 2 AZC 1045. 3.50 547 138 134 4.10 2 COMBINED AT BOX 8282. 5.25. 5454. 1515. 1469. 31.40 ROUTED TO STRM2 8256. 5.50 5440. 1517. 1471. 31.40 HYDROGRAPH AT ECR 1851. 4.00 1074. 277. 268. 6.80 0 2 COMBINED AT - 0 COMB1 9543. 5.50 6288. 1793. 1739. 38.20 HYDROGRAPH AT 0 0 0 0 ENC 1916. 3.75 1045. 268. 260. 7.40 2 COMBINED AT 0 COMB2 10765. 5.25 7182. 2062. 1999. 45.60 - - -.- - -•.- - -.- - - - - _ -- - - SUMMARY OF KINEMATIC WAVE.- MUSKINGUM-CUNGE ROUTING - (FLOW IS DIRECT RUNOFF WITHOUT BASE FLOW) - • INTERPOLATED TO • COMPUTATION INTERVAL ISTAQ ELEMENT DT • PEAK TIME TO VOLUME . DT PEAK TIME TO VOLUME PEAK . • PEAK (MIN) , (CE'S) (MIN) (IN) (MIN) •(CE'S) • • (MIN) • . (IN) • • • STRM1 MANE . 11.25 7639.34 • 315.00 1.87 15.00 7639.34 .315.00 1.88 - • • - 'CONTINUITY SUMMARY (AC-ET) - INFLOW=0.2728E+04 EXCESS=0.0000E+000UTE'LOW=0.2729E+04 BASIN STORAGE=0.6280E+00 PERCENT ERROR= -0.1 STRM2 MANE 12.75 8263.56 331.50 1.80 15.00 8256.03 330.00 1.80 CONTINUITY SUMMARY (AC-FT) - INFLOW=0.3005E+04 EXCESS=0.0000E+00OUTFLOW=0.3008E+04 BASIN STORAGE=0.1896E+01 PERCENT ERROR= -0.1 NORMAL. END OF HEC-1 " - . • • •: • . . . • - . • • - . • . - - - - - - - - - - - - - - - : - - - HEC1 SIN: 1343001570 HMVersion: 6.33 Data File: y:\sandiego\pos-bur2.hcl ***********k******4******** 4*4*4*4*444*4* * * * FLOOD HYDROGRAPH PACKAGE (HEC-1) + MAY 1991 * * VERSION 4.0.1E * * * * RUN DATE 11/26/1996 TIME 21:58:21 * * *44*4*4*4*4 ** * *4*4*44*4*4*444* k* ** 4*4*4* **** ******** ******+***+************** * * * U.S. ARMY CORPS OF ENGINEERS * * HYDROLOGIC ENGINEERING CENTER * 609 SECOND STREET * * DAVIS, CALIFORNIA 95616 * * (916) 756-1104 * * x x xxxxxxx xxxxx X . x x x x x. xx x x x xxxxxxx xxxx x xxxxx x x x x x x x x x x x x xxxxxxx xxxxx xxx Full Microcomputer Implementation by Haestad Methods, Inc. 37 Brookside Road * Waterbury, Connecticut 06708 * (203) 755-1666 THIS PROGRAM REPLACES ALL PREVIOUS VERSIONS OF HEC-1 KNOWN AS HEC1- (JAN 73), HEC1GS, HEC1DB, AND HEC1KW. THE DEFINITIONS OF VARIABLES -RTIMP- AND -RTIOR- HAVE CHANGED FROM THOSE USED WITH THE 1973-STYLE INPUT STRUCTURE. THE DEFINITION OF -AMSKK- ON RN-CARD WAS CHANGED WITH REVISIONS DATED 28 SEP 81. THIS -IS THE FORTR.AN77 VERSION NEW OPTIONS: DAMBREAK OUTFLOW SUBMERGENCE , SINGLE EVENT DAMAGE CALCULATION, DSS:WRITE STAGE FREQUENCY, DSS:READ TIME SERIES AT DESIRED CALCULATION INTERVAL LOSS RATE:GREEN ANDAMPT INFILTRATION KINEMATIC WAVE: NEW FINITE DIFFERENCE ALGORITHM - - - - - - - . - - - - - - - - - - HEC-1 INPUT ' PAGE LINE . ID.. ....... 1 .......2 .......3 .......4 .......5 .......6 .......7 .......8 .......9 ......10 DIAGRAM . 1 ID .2 ID 3 ID 4 '. ID 5 ID . . . WOODWARD-CLYDE CONSULTANTS 6 ID 7 ID 8 ID 9 'ID 10 ID 11 ID . CARLSBAD FIRESTORM 12 ID . POS-BURN W/DRAWDOWN 2 YEAR 6-HOUR STORM 13 ' ID FILE NAME: POS-BUR2 NOVEMBER 26, 1996 14 ID .....I ........2 .......'3 .......4 .......5 .......6 .......7 ......8 ..............1D 15 ID 16 IT 15 100 17 IN. 8 . . . 18 10 * 0 * REMOVE DAM and ITS WATERSHED BECAUSE DRAWDOWN TRAPS THE WATER FOR A 2-YR STORM .19 KK PtZC 20 PB 1.18 21 PC .009 .016 .025 .034 .045. .054 .065 .077 .090 .104 22 PC .120 . .137 .157 .180 .210 .255 .322 .410 ' .506 .588 23 PC .629 .656 '.679 700 .720 .739 .756 .772 .790 - .800 24 PC .816 .831 .845 .860 .872 .885- - .895 .905 .914 ' .924 25 PC .935 .945 .954 .963 . .972 .981 .991 1.000 26 BA 4.1 27 - LS 0 73 . . . 28 ' - UD 0.89 - 29 - KK STRN2 30 RD 8500 0.0035 0.04 TRAP 600 10 31 KK CCR 32 . - PB 1.18 33 BA 6.8 34 LS 0 .77 35 ,UD * 1.26 . . . 36 KK COMB1 . . 37 KM COMBINE RUNOFF FROM ECR AND STRM2 38 MC 2 - - - - - - - - - - - - - - - - - - - HEC-1 INPUT PAGE 2 LINE ID ....... I .......2 .......3 ......4. .......5 ........6 .......7 .......8 .......9 ......10 • 39 KK ENC • 40 PB .89 41 • BA 7.4 • • 42 LS 0 85 43 UD 1.18 • • 44. KM COMB2 • •. • S S S S 45 KM COLLECTION POINT--COMBINE HYDROGRAPHS FROM COMB1 AND ENC . 46 HC 2, • S 47 ZZ S S - - - - - - - - - - - - - - - - - - - RUNOFF SUMMARY FLOW IN CUBIC FEETPER SECOND TIME IN HOURS, AREA IN SQUARE MILES PEAK TIME OF AVERAGE FLOW FOR MAXIMUM PERIOD BASIN MAXIMUM TIME OF OPERATION STATION FLOW PEAK AREA STAGE MAX. STAGE. 6-HOUR 24-HOUR 2-HOUR HYDROGRAPH AT AZC 38 6.25 , 21. 5 5 410 ROUTED TO STRM2 53 8.25 20 6 5 .4 .10 HYDROGRAPH AT ECR 104. 6.00 68. 17. 17: 6.80 2 COMBINED AT COMB 104. 6.00 76. 23. 22. 10.90 HYDROGRAPH AT . ENC 143. 5.00 97. 25. 24. 7.40 2 COMBINED AT COMB2 243. 5.50 171. 48. 46. 18.30 .- - - - -.- -- -- -.- -.- - SUMMARY OF KINEMATIC WAVE - MUSKINGUM-CUNGE ROUTING (FLOW IS DIRECT RUNOFF WITHOUT BASE FLOW) INTERPOLATED TO COMPUTATION INTERVAL ISTAQ ELEMENT DT PEAK TIME TO VOLUME DT PEAK TIME TO VOLUME PEAK PEAK (MIN) (CE'S) (MIN) (IN) (MIN) (CE'S) (MIN) (IN) STRM2 MANE 11.25 52.88 495.00 0.05 15.00 52.88 495.00 0.05 CONTINUITY SUMMARY (AC-Fl) - IMFLOW=0.1024E+02 E<CESS=O.00OOE+00 OUTFLOW=0.1082E+02 BASIN STORAGE=0.1069E+00 PERCENT ERROR= -6.7 - - - - - - - - - - - - - - - - - - - NEC-i INPUT PAGE LINE ID ..... ..1 ........2 .......3 .......4 .......5 .......6 .......7 .......B .......9 ......10 1 ID : 2 ID 3 ID - 4 ID - 5 ID * * 6 ID * WOODWARD-CLYDE CONSULTANTS * 7 ID * * 8 ID 9 ID -. to ID 11 ID 12 ID CARLSBAD FIRESTORM .13 ID POS-BURN W/DRAWDOWN 25 YEAR 6-HOUR STORM 14 ID FILE NAME: POS-BUR2 NOVEMBER 26, 1996 15 ID .....1 .......2 .......3 .......4 .......5 .......6. .-.-... 7 .......8 .......9 ...... 1.0 --16 ID 17 IT 15 100 18 IN 8 19 19 * 0 . . . 20 KK LSM . 21 . PB 2.80 22 PC .009 .016 .025 .034 .045 .054 .065 .077 .090 .104 23 PC .120 .137 .157 .180 .210 .255 .322 .410 .506 .588 24 - PC .629 .656 .679 .700 .720 - .739 .756 .772 .790 .800 25 PC .816 .831 .845 .860 .872 .885 .895 .905 .914 .924 26 . PC .935 .945 .954 .963 .972 .981 .991 1.000 27 - BA 27.3 . 28 LS 0 82 29 - .UD * 1.86 30 KK DAN - 31 RS 1 ELEV 488 32 .SA - 5 59 59 59 -- 33 - SE 413 488 493 503 34 - . . SS . 493 - 325 3.3. - 1.5 -- 35 - KK STRN1--- 36 RD 18000--- 0.0228 0.04 TRAP 50 3 -- - 37 -KK -. - AZC., 38 PB 2.80 - . -- 39 BA 4.1 - 40 LS 0 73 I I I I I I I I I I I I I I II I I I I H -.- HEC-1 INPUT PAGE 2 LINE ID.1.2.3. 4.5.6.7.8.9.. 10 42 KK BOX 43 KM COMBINE RUNOFF FROM STRM1 AND AZC 44 HC 2 0 45 KK STRN2 0 46 RD 8500 0.0035 0.04 TRAP 600 10 47 KK 0 ECR 48 PB 2.80 49 BA 6.8 50 LS 0 77 0 51 UD • 1.26 • 0 52 KK COMB1 53 KM COMBINE RUNOFF FROM ECR AND STRM2 • 54 HC 2 0 55 KK ENC • 56 PB 2.10 57 BA 7.4 • 58 LS 0 85 0 59 UD 1.18 60 KK COMB2 61 KM COLLECTION POINT--COMBINE HYDROGRAPHS FROM COMB1 AND ENC • 62 NC 2 .63 ZZ RUNOFF SUMMARY FLOW IN CUBIC FEET PER SECOND TIME IN HOURS, AREA IN SQUARE MILES PEAK TIME OF AVERAGE FLOW FOR MAXIMUM PERIOD BASIN MAXIMUM TIME OF OPERATION STATION FLOW. PEAK AREA STAGE MAX STAGE 6-HOUR 24-HOUR 72-HOUR HYDROGRAPH AT LSM 4966. 4.75 - 3327. 898. 871. 27.30 ROUTED TO DAM 4760. 5.25 2837. - 749. 727. 27.30 495.69 5.25 ROUTED TO - STRN1 4767. 5.50 2838. 755. 732. 27.30 HYDROGRAPH AT AZC 568. 3.75 321. 81. 79. 4.10 2 COMBINED AT . BOX 5149. 5.50 3017. 836. 811. 31.40 ROUTED TO STRM2 - 5108. 6.00 3007. 839. 814. 31.40 HYDROGRAPH AT ECR 1088. 4.00 663. 171. 166. 6.80 - 2 COMBINED AT COMB1 5852. 6.00 3425. 1010. 979. 38.20 HYDROGRAPH AT 0 0 ENC 1185. 4.00 674. 173. 168. 7.40 2 COMBINED AT COMB2 6572. 5.75 3965. 1183. 1147. 45.60 - - - - - - - - - - - - - - - - - - SUMMARY OF KINEMATIC WAVE - MUSKINGUM-CUNGE ROUTING (FLOW IS DIRECT RUNOFF WITHOUT BASE FLOW) INTERPOLATED TO COMPUTATION INTERVAL ISTAQ ELEMENT DT PEAK TIME TO VOLUME DT PEAK TIME TO VOLUME PEAK PEAK (MIN) (CFS) (MIN) (IN) (MIN) (CFS) (MIN) (IN) STRM1 MANE 3.75 4767.48 j30.00 1.02 15.00 4767.48 330.00 1.03 CONTINUITY SUMMARY (AC-FT).- INFLOW=0.1486E+04 EXCESS=O.0000E+00 OUTFLOW=0.1487E+04 BASIN STORAGE=0.5902E+00 PERCENT ERROR= -0.1 STRM2 MANE 8.25 5137.22 354.75 '0.99 15.00 5108.46 360.00 0.99 CONTINUITY SUMMARY (AC-FT) - II'IFLOW=0.1659E+04 EXCESS=O.0000E+00 OUTFLOW=0.1661E+04 BASIN SToRAGE=0.!791E+01 PERCENT ERROR= -0.2 - - - - - - - - - - - - - - - - - - HEC-1 INPUT PAGE LINE ID ....... 1 ....... 2 ....... 3 ....... 4 ....... 5.6 .8.9.10 1 ID 2 ID 3 ID 4 ID 5 ID * NOODWARD-CLYDE CONSULTANTS .6 ID 7 ID *********4'**********4'*********•*************** 8 ID 9 ID 10 ID 11 ID CARLSBAD FIRESTORM 12 ID POS-BURN W/DRAWDOWN 50 YEAR 6-HOUR STORM 13 ID EILE'NANE: POS-BUR2 NOVEMBER 26, 1996 14 ID .....1 .......2 .......3 .......4 .......5 .......6 .......7 .......8 .......9.......10 15 ID 16. IT 15 100 17 IN 8 18 ' 10, * 0 19 -KK LSM 20 PB 3.21 21' PC .009 .016 .025 .034 '.045 .054 .065 .077 .090 .104 22 ' PC .120 .137 .157 .180 .210 .255 .322 .410 .506 .588 23 PC .629 .656 .679 .700 .720 .739 .756 .772 .790 .800 24 , PC .816 .831 .845 .860 .872 .885 . .895 .905 .914 .924 25 PC .935 .945 .954 .963 .972 .981 .991 1.000 26 , BA 27.3 27 LS 0 82 28 lID * 1.86 29 KK DAM . 30 RS 1 ELEV 488 31 SA - 5. 59 59 59 - 32 SE 413 , 488 493 '503 33 SS * 493- 325 3.3 1.5 - 34 KK STRM1 35 RD * 18000 0.0228 0.04. TRAP 50 . 3 36. . -KK, AZC. 37 PB 3.21 38 BA 4.1 39 LS 0 73 40 'lID 0.89 - HEC-1 INPUT PAGE 2 LINE ID.......1 .......2 .......3 .......4 .......5.......6 .......7 .......8 .......9 ......10 41 KK BOX 42 KM COMBINE RUNOFF FROM STRM1 AND AZC 43 MC 2 44 KK STRM2 45 'RD * 8500 0.0035 0.04 TRAP 600 10 46 KK 6CR : 0 47 PB 3.21 48 BA 6.8 49 LS 0 77 50 UD * 1.26 51 KK COMBI 52 KM COMBINE RUNOFF FROM 6CR AND STRM2 0 .53 HC * 2 54 KK ENC 0 55 PB 2.41 56 BA 7.4 0 57 LS 0 0 85 0 58 UD. 1.18 0 0 59 KK COMB2 60 KM 0 COLLECTION POINT--COMBINE HYDROGRAPHS FROM COMB1 AND ENC 61 MC 2 62 ZZ RUNOFF SUMMARY FLOW IN CUBIC FEET PER SECOND TIME IN HOURS, AREA IN SQUARE MILES PEAK TIME OF AVERAGE FLOW FOR MAXIMUM PERIOD BASIN MAXIMUM TIME OF OPERATION STATION . FLOW PEAK AREA STAGE MAX STAGE 6-HOUR 24-HOUR .72 -HOUR HYDROGRAPH AT LSM 6359. 4.75 4204. 1135. 1101. 27.30 ROUTED TO . . DAM .6177. 5.25 3729. 986. . 956. ' 27.30 496.21 5.25 ROUTED TO 'STRMl 6178. 5.25 ' 3728. 993. 963. 27.30 -. HYDROGRAPH AT AZC ' 794. 3.50 431. 109. 106. 4.10 2 COMBINED AT BOX 6701. 5.25 3984. 1102. 1069. 31.40 ROUTED TO STRM2 6674.. 5.75' 3971. 1103. , 1070. 31.40' HYDROGRAPH AT" ECR 1461. 4.00 ' 865. 223. 216. 6.80 ' 2 COMBINED AT COMB1 .7668. 5.75 4559. 1326.1 1286. 38.20 HYDROGRAPH AT ENC 1544. 3.75 859. 220. 214'. 7.40 ' 2 COMBINED AT . ' COM82 8645. 5.50 5274. 1547. 1500. 45.60 SUMMARY OF KINEMATIC WAVE - MUSKINGUM-CUNGE ROUTING (FLOW IS DIRECT RUNOFF WITHOUT BASE FLOW) INTERPOLATED TO COMPUTATION 'INTERVAL ISTAQ ELEMENT DT PEAK TIME TO VOLUME DT PEAK TIME TO VOLUME PEAK PEAK (MIN) (CE'S) (MIN) (IN) (MIN) (cE'S) (WIN) (IN) STRM1 MANE 4.50 6178.72 319.50 1.34 15.00 6178.2 315.00 1.35 CONTINUITY SUMMARY (AC-FT) - INFLOW=0.I956E+04 EXCESS=0.0000E+00 OUTFLOW=0.1958E04 BASIN STORAGE=0.6057E+00 PERCENT ERROR= -0.1 STRM2 MANE 8.2,5 6683.87 346.50 1.31 15.00 6674.22 345.00 1.31 CONTINUITY SUMMARY (AC-FT) - INFLOW=0.2185E+04 EXCESS=0.O000E+00oUTE'LOW=0.2187E-04 BASIN STORAGE=0.1796E+01 PERCENT ERROR= -0.2 -- - - - No - - - - - - - - - - - - NEC-i INPUT S PAGE LINE ID ...... .1 .......2 .......3 .......4 .......5 ........6 .......7 ........8 ........9 ......10 1.. ID 2 . ID 3 ' ID A ID * WOODWARD-CLYDE CONSULTANTS, 5 ID * 6 ID 7 'ID 8 ID 9 ID ' 10 ID CARLSBAD'FIRESTORM 11 ID POS-BURN W/DRA'JDOWN 100 YEAR 6-HOUR STORM 12 , ID FILE NAME: POS-BUR2 NOVEMBER 26, 1996 V 13 ID .....1 .......2 .......3 .......4 ........S .......6 .......7 .......8 .......9 ......10 14 ID 15 IT 15 100 V 16 IN 8 17 ' 10 * 0 V .18 KK LSM 19 PB 3.61 20 PC .009 ' .016 .025 .034 .045 .054 .065 .077 .090 .104 21 PC .120 .137 .157 .180 .210 .255 .322 .410 .506' .588 22 PC .629 .656 .679 .700 .720 .739 .756 .772 .790. .800 23 PC .816 .831 .845 .860 .872 .885 .895 .905. .914 . .924 24 , PC .935 .945 .954 .963 .972 .981 .991 1.000 S 25 BA 27.3 • • . . • V 26 . LS 0 :82' 27 ' UD * 1.86 . S 28. KK DAM V 29 RS 1 ELEV 488 30 ' SA 5 59 59 59 • 31 SE 413 488 493 503 . V 32 SS * 493 325 3.3 1.5 V 33 KK STRM1 34 RD 18000 0.0228 0.04 . TRAP 50 3 • V • V V • 35 KK AZC • V S • V V, V 36 PB 3.61 5 . S • 37 BA V 4.1 V • V, • 38- LS 6 13 V • V • 39 UD S * 0.89 V S V - - - - - - - - - - - - - - - - - - - • HEC-1 INPUT PAGE 2 LINE ID ...... ..1 .......2 .......3 .......4 .......5 .......6 .......7 .......8 ........9 ......10 43 K}( STRM2 . . 44 RD * 8500 0.0035 0.04. TRAP 600 10 - •1 45 KK ECR . . . 46 . PB. 3.61 • .. . . . 47 BA 6.8 • 48 LS 0 . . . . . 49 .UD. * .1.26 • . • . . . 50 KK COMB1 . 51 KM COMBINE RUNOFF FROM ECR AND STRM2 • . . 52 MC * 2 53 KK ENC • 54 PB • 2.71 . . . . . . 55 BA 7.4 . -. . . • 56 LS 0 85 : . • . . . . . 57 - UD * 1.18 • . .. . - • • 58 KK COMB2 • . . . . • - 59 KM COLLECTION POINT--COMBINE HYDROGRAPHS FROM COMB1 AND ENC . . . 60 . HC 2 61 ZZ . . . . . . - • . . • - - - - - - - - - - - - - - - - - - - RUNOFF SUMMARY FLOW IN CUBIC FEET PER SECOND TIME IN HOURS, AREA IN SQUARE MILES • PEAK TIME OF AVERAGE FLOW FOR MAXIMUM PERIOD BASIN MAXIMUM TIME OF OPERATION STATION FLOW PEAK , AREA STAGE MAX STAGE 6-HOUR 24-HOUR 72-HOUR HYDROGRAPH AT LSM 7778. 4.75 5093. -1376. 1334. 27.30 ROUTED TO • DAM 7624. 5.00 4629. 1227. 1189. 27.30 • 496.70 5.00 ROUTED TO • • STRMI 7625. 5.25 4617. 1230. 1193.. 27.30 HYDROGRAPH AT • AZC 1045. 3.50 • 547. 138. 134.•, 4.10 2 COMBINED AT • - BOX 8268 5.25 4952 1368 1327 3 40 ROUTED TO • . -. S STRM2 8238. 5.50 4943. .1371. 1329. 31.40 - HYDROGRAPH AT - - - • ECR 1851 4.00 1074 277 268 6.80 2 COMBINED AT - COMB1 - 9525. 5.50 • 5717. 1647. 1597. 38.20 HYDROGRAPH AT - S ENC 1916. 3.75 - 1045.. 268. 260. 7.40 2 COMBINED AT COM82 10691. 5.50 6613. 1915. 1857. 45.60 5 - - - - - - - - - - - - - - - - - - - • SUMMARY OF KINEMATIC WAVE- - MUSKINGUM-CUNGE ROUTING (FLOW IS DIRECT RUNOFF WITHOUT BASE FLOW) - INTERPOLATED TO COMPUTATION INTERVAL ISTAQ ELEMENT DT PEAK TIME TO" VOLUME DT PEAK TIME TO VOLUME • PEAK PEAK (WIN) (CE'S) (WIN) (IN) (MIN) (CES) (MIN) (IN) STRMJ MANE 4.50 7624 95 315.00 1.67 15.00 7624 95 315.00 1.68, CONTINUITY SUMMARY (AC-FT) - INFLOW=0 2433E+04 EXCESS=0 0000Ef00 OUTFLOW=0 2436E+04 BASIN STORAGE=O 6141E+0O PERCENT ERROR= -0.1 STRM2 MANE 9.00 8255.61 333.00 1.62 15.00 8238.03 330.00 1.62 • : CONTINUITY SUMMARY (AC-FT) - INFLOW=0.2717E+04 EXCESS=0.0000E#00 OUTFLOW=0.2719E404 BASIN STORAGE=0.1789E+01 PERCENT ERROR= -0.1 APPENDIMB Details and Standard Specifications STANDARD SPECIFICATION SHEET PROJECT NAME: Harmony Grove Fire, City of Carlsbad PRACTICE NAME: SF1 Prefabricated Silt Fencing DESCRIPTION: S Prefabricated silt fences are constructed of geotextile attached to wooden support st a k e s . T h e fabric itself shall be of.. woven polypropylene or polyester treated to resis t u l t r a - v i o l e t degradation. The fabric shall extend a minimum of two feet above the ground surface an d t h e s t a k e s a minimum of 36 inches in length so that at least 12 inches of stake is driven into the groun d . T h e silt fence is generally placed along the contour such that it does not channel water or d e b r i s a l o n g its length. INSTALLATION PROCEDURES: S S I. Using trencher or shovel, dig a trench along the line where the fence is to b e i n s t a l l e d ; minimize disturbance. Unroll the fence, place it upright in the trench with the bottom flap in the excavated t r e n c h . Hammer the stakes into the trench bottom with the stakes on the downstream side. Backfill the trench with soil, compacting the material onto the bottom flap of the geote x t i l e . WOodWard.CIydO S W9651135F\ECO1-D-R.DOC10-Mar-97\9651135F\SDG B-i I . _T_ 2' (MIN.) PREFABRICATED MATERIAL ATTACHED TO WOODEN POSTS BACKFILLED TRENCH WOODEN POSTS TO FABRIC AITACHED j- ULTRAVIOLET-STABILIZED / FABRIC MATERIAL ANCHORED / IN TRENCH S COMPACTED BACKFILL RUNOFF 1(!4IM) TRENCH PRACTICE SF1 PREFABRICATED SILT FENCING HARMONY GROVE FIRE, Clii OF CARLSBAD FN: S-FENCE DRAWN BY JMA CHECKED BY: PROJECT Nth 9651135F (IlAiTE: 12-17-96 FiGURE NO: SF1 I • WOODWARD-CLYDE APPENDIXB Details and Standard Specifications STANDARD SPECIFICATION SHEET PROJECT NAME: Harmony Grove Fire, City of Carlsbad PRACTICE NAME: GB2A Gravel-Filled Burlap Bag Check Dams DESCRIPTION: Gravel-filled burlap bags may be used for temporary check dams in areas of concentrated flow. The burlap bag flaps shall be folded under the bags in a direction away from the water flow. Gravel bag check dams shall be spaced such that the crest of the downstream check dam is approximately level with the toe of the upstream check darn. Each check dam shall be installed so the side and end points are higher than the centerline crest. Erosion caused by high flows around the edges shall be corrected immediately. Collected sediment shall be removed when it reaches one-half the height of the check dam. Woodward-Clyde W:\9651135F\ECO1-D-R.DOC1O-Mar-97\9651135F\SDG B-2 AAXIMUM 18-20" HEIGHT WATER FLOW - FRONT VIEW: SIDE VIEW: NARROW SWALES 2 BAGS HIGH FRONT VIEW: SIDE VIEW: IJADDAW 4ZWAI r4Z NARROW SWALES FOLD FLAPS AWAY FROM WATER FLOW ALTERNATE BAGS WATER FLOW ( Cr) i- PLACE DOWNSTREAM BALES SUCH I THAT POINT "B" IS APPROXIMATELY I LEVEL WITH THE LOWEST GROUND / ELEVATION OF THE UPSTREAM BALE PRACTICE GB2A GRAVEL-FILLED BURLAP BAG CHECK DAMS HARMONY GROVE FIRE, CITY OF CARLSBAD FN: C-BCD DRAWN BY. JMA I CHECKED BY: PROJECT NO: 9651135F DATE: 12-17-96 1 FiGURE NO: G132A I WOOD WARD-CLYDE APPENDIXB Details and Standard Specifications STANDARD SPECIFICATION SHEET : PROJECT NAME: Harmony Grove Fire, City of Carlsbad PRACTICE NAME: GB2B Gravel-filled Burlap Bags for Inlet Filter DESCRIPTION: Burlap bags may be filled with gravel to filter runoff water before it enters storm drain inlets. The bags shall be filled with 1 inch clean gravel and placed in alternating rows around the perimeter of each drain, overlapped and folded as described in Practice GB2A. The system shall be inspected during and after storm events and repaired if necessary. Sediment shall be removed when it covers the first course of bags. W9651135F\ECO1-D-R. DWI O-Mar-979651135FSOG B-3 GRAVEL BAG FILTER (APPROXIMATELY 1 INCH DIAMETER ROCK PLACED IN BURLAP BAGS. \ A\ I \ 4 •• :. - . I \ - • I IO.WU iN LkJLN hAl IN IQ =1 ... ... 4 . 4 I .4. : 1• I - . _______________________ . a AREA INLET .WITHGRATE A - OVERFLOW . N mm FILTERED WATER . .. SECTION AA GRAVEL FILTER CAN BE USED ON . . PAVEMENT OR BARE GROUND PRACTICE GB213 . . I GRAVEL-FILLED BURLAP BAGS FOR INLET FILTER HARMONY GROVE, FIRE, CITY OF CARLSBAD - FN: ROC....F1L DRAWN BY: JMA CHECKED BY: PROJECT NO: 9651135F DATE 12-17-96 FIGURE NO: GB2B WOODWARD-CLYDE APPENDIXB Details and Standard Specifications STANDARD SPECIFICATION SHEET PROJECT NAME: Harmony Grove Fire, City of Carlsbad S PRACTICE NAME: GB2C Gravel-filled Burlap Bag for Curb Inlet Filter DESCRIPTION: Burlap bags can be filled with gravel to filter runoff water before it enters curb drain inlets. The bags shall be filled with 1-inch diameter clean gravel and placed in a semicircular configuration around each drain. They shall be. overlapped and folded as described in Practice GB2A. As with all sediment control structures, the system shall be inspected periodically, as well as during and after storm events, and sediment shall be removed when it covers the bottom layer of bags. : S Gravel-filled burlap bags may also be used as velocity reduction and sediment retention structures along the curbs of roads, where a line of alternating bags, 2 feet high and 8 to 10 feet long are placed up gradient and away from the curb at an angle not to exceed 30 degrees. WOOdW$d.CIYdO W:9651 135F\ECO1-D-R.DOC10-Mar.97\9651135F\SDG B-4 -U I-' SECTION A-A' GRAVEL FILTER CAN BE USED ON PAVEMENT OR BARE GROUND PRACTICE G132C GRAVEL-FILLED BURLAP BAGS FOR CURB INLET FILTER HARMONY GROVE FIRE, CITY OF CARLSBAD FN: C-CIF DRAWN BY: JMA I CHECKED BY: PROJECT N0 9651135F DATE: 12-17-96 1 FIGURE NO: G132C WOODWARD-CLYDE I APPENDIXB Details and Standard Specifications STANDARD SPECIFICATION SHEET PROJECT NAME: Harmony Grove Fire, City of Carlsbad I PRACTICE NAME: CC3 Cellular Confinement System at Arizona Crossing DESCRIPTION: I Cellular confinement is a lightweight flexible, polyethylene confinement system consisting of three-dimensional cells in a honeycomb-like structures. After installation with on-site fill materials the confinement material acts as a semi-rigid slab, distributing loads laterally, reducing I sub-grade contact pressures, and reducing conventional storm design base thickness by 50 percent. When combined with on-site fill materials, the confinement system creates an economical expedient structural base. A standard section of the confinement material has I nominal expanded dimensions of 2-inch, 3-inch, 4-inch, 6-inch, and 8-inch cell depths, with a width of 8 feet. The cells are uniform in shape and size. I Stake placement is recommended for the purpose of keeping the cells straight and round as the infill materials is added. The stakes may be rebar, wood, metal, or similar. The subgrade should be prepared to accommodate anticipated traffic loads. Soft or wet 1 subgrades should be improved by means of a suitable geotextile. Run a string line or chalk line center or side border for the width and length of the cellular ' confinement material to be installed. Set stakes approximately 8 inches apart over both the length and width. The material should be interlocked with the edge cells overlapping by 4 inches and the end I cells touching; if necessary, staples, hog rings, or clamps should be used. 4. A front end loader bucket is the preferred equipment for filling the grid. The infill I should be shaken or sprinkled until the cells are at least partially filled and then the loader can dump its bucket and spread the infill by floating the bucket over the cells. The cells should be overfilled by approximately 2 inches to allow the loader to drive over the cells without I damaging the cell walls. A ramp of infill material should be built over the top of the grid and compacted. After compaction, a minimum surcharge of 1 inch should be left over the grid. I I I I I WOO rd.CIydo W:\9651135FECO1-D-R.DOC%10.Mar-97%9651 1 35F\SDG B-S I * I " CLEAN GRAVEL cm OCk,70C=,V- PROFILE CELLULAR 1" CLEAN GRAVEL CONFINEMENT SPILLWAY DETENTION BASIN PLM VIEW PRACTICE CC3 CELLULAR CONFINEMENT SYSTEM AT ARIZONA CROSSING HARMONY GROVE FIRE, CITY OF CARLSBAD FN: GEOGRID DRAWN BY: CB J CHECKED BY: J PROJECT NO: 9651135F DATE: 12-17-96 RGIJRE NO: CC3 I WOODWARD-CLYDE Critical Water Limit Water Revetment Thickness Stone Size Velocity Velocity inches cm. Type Diameter (fps) (fps) Gabion Mattress 6 15 3" to 6" 9 14 9 23 to 6" 12 17 Gabions 12 30 to 8" 15 19 18 45 4'108" 21 26 I I I I I I APPENDIXB Details and Standard Specifications STANDARD SPECIFICATION SHEET PROJECT NAME: Harmony Grove Fire, City of Carlsbad PRACTICE NAME: GM4 9-inch Gabion Mattress DESCRIPTION: Gabions are fabricated from welded corrosion-resistant steel wire mesh formed into large boxes, usually rectangular in shape but variable in size, designed to create flexible structures. Gabions are erected at the project site, quickly joined together, and filled with stones, often obtained on site. Highly permeable gabion structures act as self draining units which bleed off ground waters, relieve hydrostatic heads, and dissipate energy from flood, current, and wave action. When utilizing gabions for a structure that will be driven over, an asphalt-concrete topper should be applied over the top to prevent damage to the wire mesh. The following is general guidance for gabion channel revetments: I F it I WøodwardCtydo W:\g651135F\ECO1-D-RDOC1O-Mar.97\9651135F\SDG B6 I ADUAI T_1"AIJCDT SPILLWAY ABION MATTRESS ASPHALT CONCRETE DETENTION BASIN PLAN VIEW PRACTICE GM4 9-INCH GABION MATTRESS AT ARIZONA CROSSING HARMONY GROVE FIRE, CITY OF CARLSBAD FN: GABON DRAWN BY: CB CHECKED BY: PROJECT NO: 9651135F DATE: 12-17-96 1 FIGURE N0 GM4 WOODWARD-CLYDE I APPENDIIIB V Details and Standard Specifications I V STANDARD SPECIFICATION SHEET PROJECT NAME: Harmony Grove Fire, City of Carlsbad V I PRACTICE NAME: FC5 Flexible Concrete Revetment DESCRIPTION: I. Flexible concrete revetment consists of machine compressed cellular concrete blocks of a unique interlocking shape which are made up into mats for easy handling. The blocks are constructed of 4,000 psi concrete that is sulfate-resistant to ensure durability. The revetment permits up to 1 20 percent open area to provide for free drainage of water and the growth of vegetation. The revetment is free of projections so pedestrians, animals, and vehicles have safe and convenient :I access. The revetment is also flexible to form to any underlying surface. V BLOCK SPECIFICATIONS 1 (Typical Values) V Concrete Block Class Specific Weight lbs/cu ft Compressive Strength lbs/sq in Maximum Absorption Nominal Dimensions, in - Gross Area/ Block sq ft Block Weight" Open Area % A B C lbs lbs/sq ft S-Class Open Cell 30S 130-150 4,000 l2 lbs/cu ft 13.0 11.6 4.75 0.98 31-36 32-37 20 50SI 130-150 4,000 12 lbs/cu ft 13.0 11.6 6.0 0.98 45-52 45-53 20 S-Class Closed Cell 455 130-150 4,000 12 lbs/cu ft 13.0 11.6 4.75 0.98 39-45 40-45 10 555 130-150 4,000 12 lbs/cu ft 13.0 11.6 6.0 0.98 53-61 54-62 10 Open Cell 40 130-150 4,000 12 lbs/cu ft 17.4 15.5 4.75 1.77 62-71 35-40 20 50 130-150 V 4,000 12 lbs/cu ft 17.4 15.5 6.0 1.77 81-94 46-53 20 60 130-150 4,000 12 lbs/cu ft 17.4 15.5 75 1.77 99-113 56-64 20 70 130-150 4,000 12lbs/cuft 17.4 15.5 9.0* 1.77 120-138 68-78 20 Closed Cell 45 130-150 4,000 12lbs/cuft 17.4 15.5 4.75 1.77 78-89 43-50 10 55 130-150 4,000 12lbs/cuft 17.4 15.5 6.0 1.77 94-108 53-61 10 75 130-150 4,000 12lbs/cuft 17.4 15.5 7.5 1.77 120-138 68-78 10 85 130-150 4,000 12lbs/cuft 17.4 15.5 9.0* 1.77 145-167 82-95 10 LI ~ I d WOOdWardCIyde 0 W:\9651135F\ECO1-D-R.DOC\1 0-Mar-97',9651135FSDG B-7 I I-] PROFILE FLEXIBLE CONCRETE REVETMENT -- u ___ ..• II s IIr El .- DETENTION BASIN .. PLAN VIEW .. PRACTICE FC5 FLEXIBLE CONCRETE REVETMENT AT ARIZONA CROSSING HARMONY GROVE FIRE, CITY OF CARLSBAD FN: RFLEX DRAWN BY: CB I CHECKED BY: J PROJECT NO: 9651135F • DATE: 12-17-96 FIGURE NO: FC5 I • . •• • ••• . • WOOD WARD-CLYDE. . APPENDIXB Details and Standard Specifications STANDARD SPECIFICATION SHEET PROJECT NAME: Harmony Grove Fire, City of Carlsbad PRACTICE NAME: KR-6 Concrete Traffic Barriers (K-Rail) DESCRIPTION: Concrete traffic barriers or "K-rail" are 2-foot high rectangular shaped concrete blocks that can be attached together to form a wall or barrier. These barriers can be placed perpendicular to on- coming flow to impede the niovement of sediment downstream. At the Arizona crossing the traffic barriers should be placed on either side of the road and the compacted fill should be placed in between the two barriers. Rip rap or gravel-filled bags should be placed upstream of the toe of the barriers and also at their abutting ends to seal and prevent movement of sediment beneath or through the barrier walls. Woodward.Clyde W:\9651135FECO1-D-R.DOC1O-Marg7\9651135F\SOG B-8 CONCRETE K-RAIL UPSTREAM FRONT VIEW DETENTION BASIN PROFILE )N mdruls w..T - PRACTICE KR CONCRETE TRAFFIC BARRIER (K-RAIL) AT ARIZONA CROSSING HARMONY GROVE FIRE, CITY OF CARLSBAD FN: BARRIER DRAWN BY: CB CHECKED BY: PROJECT N0 9651 135F DATE: 12-17-96 FIGURE NO: KR6 WOOD WARD-CLYDE I APPENDIXB Details and Standard Specifications STANDARD SPECIFICATION SHEET PROJECT NAME: Harmony Grove Fire, City of Carlsbad I PRACTICE NAME: TL7 Temporary Levees DESCRIPTION: I Temporary levees are polyethylene or woven geotextile tubes that are pumped full of water. Two Winner tubes contained by one master tube provide counter friction and result in a stable non- rolling wall of contained water which adjusts automatically to bottom terrain. The tubes come in I .inflated heights anywhere from 1 to 8 feet and weigh anywhere from 105 to 11,000 lbs. per linear foot when filled. No residual fill materials are necessary to deploy the structures and they are easily removed when necessary. . 1 . . . .1 . I. S . ., S5 •S i . WOOd N rd-Clyde S W:\9651135FECO1-D-R.DOC1O-Mar-97't9651135F\SDG B-9 1 OUTER TUBE R TUBE/ INNER TUBE TUBE La lx 0 WATER OUTER TUBE ,STRUCTURESe, GOLF 8 INNER COURSE TUBES iv 'S. CORE MATERIAL FOR INSTALLATION AND TRANSPORTATION PLAN VIEW 19felloofm 14ed e!ght Empty Empty 1 ft 24 In 1.0 lb 105 lb 12.5 2 ft 46 In 1.5 lb 420 lb 50 3 ft 68 In 2.6 lb 1,130 lb 135 PROFILE 4 ft 120 In 4.0 lb 2,400 lb 290 6 ft 186 In 9.0 lb 5,800 lb 700 - 8 ft 282 In 17.9 lb 11,000 lb 1,270 PRACTICE TL7 TEMPORARY LEVEES (WATER STRUCTURES) HARMONY GROVE FIRt, CITY OF CARLSBAD FN: WATER DRAWN BY: CB CHECKED BY; J PROJECT NO: 9651135F j DATE: 12-17-96f FIGURE NO: Th7 W000WARD-CLYDE I . APPENDIXB Details and Standard Specifications STANDARD SPECIFICATION SHEET PROJECT NAME: Harmony Grove Fire, County of San Diego I PRACTICE NAME: DM8 Dry Straw Mulch with Tackifier or Nets DESCRIPTION: I Weed-free, bright straw can be used as part of a three step surface erosion control practice, which proceeds as follows: Step 1:. Apply recommended seed mixture with hydraulic seeder, mixing in tank a I wood fiber mulch (with tackifier) at a rate of 1 to 2 bags of mulch per acre depending on soil conditions. I Step 2: Apply with straw blower, approximately 2 tons per acre of loose straw. Step 3.: Apply a tack mixture to hold straw in place at a rate (per acre) of either I 100 lbs. M binder; 150 lbs. Tak Pak or 55-gallons acrylic copolymer Where native plant materials already in the soil are expected to regenerate, the first step of DM8 practice may be eliminated. The DM8 practice is recommended to be applied to steep slopes I along roadsides accessible to mulching equipment. . Straw mulching with nets is primarily a homeowner practice, ,where using tackifier is I economically impractical on small, individual lots. For the application of straw mulching on areas not covered by the DM5 practice, straw shall be "flaked out" or shaken out by hand over the soil surface. In lieu of a tackifier application to hold the straw in place. A netting shall be I rolled out over the straw and held in place using 6-in. x 1-in. x 6-in, wire staples. Nettings which can be used are: I a. Natural fiber jute (biodegradable) b. Polyjute (photodegradable) C. Plastic netting (V2-in. x '/2-in, mesh) I I I Woodward-Clyde @ W9651135F\ECO1-D-R.DOC11-Mar-97\9651135F\SDG B-10 I I APPENDIXB Details and Standard Specifications STANDARD SPECIFICATION SHEET PROJECT NAME: Harmony Grove Fire, County of San Diego I PRACTICE NAME: SB9 Straw Bales DESCRIPTION: I Bales should be composed of weed-free, wheat or rice straw. Straw bales can be used as dikes to stabilize channel flow lines or as a perimeter filter barrier. Straw bales shall be installed in a trench, staked and backfilled if they are to be effective in reducing flow velocity and filtering I sediment from runoff. When used as a perimeter filter, sediment shall be removed when material Js within six inches of the tope of any bale. I INSTALLATION PROCEDURE: . Step 1: Dig trench across flow line the width of the straw bale. ' Step 2: Place bales on edge in trench, tightly abutted against each other with no gaps between end of bales. Step 3: Stake in place using two 1-in. x 1-in. x 36-in. (or 1-in. x 2-in. x 36-in.) stakes Step 4: Backfill and compact excavated soil along upslope edge of bale. .. . I I I I I I I WOOdWard.CIytSO W:9651 135F\ECO1-D-R.DOC\1 O-Mar-97\9651135F\SDG B-Il I .,... ., . BALES MUST BE TIGHTLY ABUTTING WITH NO GAPS 1"X2" STAKE OR 1"X1" STAKE 1-WEDGE LOOSE STRAW I BETWEEN BALES 4" MIN. - TWINE/WIRE 2. PLACE AND STAKE STRAW BALES 1. EXCAVATE THE TRENCH BACKFILL MATERIAL FROM TRENCH 3. BACKFILL AND COMPACT EXCAVATED SOIL 1"X2" WOOD STAKE STAKED AND ENTRENCHED (OR 1"X1 50 LB. (APPROXIMATE) STRAW BALE TWINE/WIRE COMPACTED SOIL TO PREVENT PIPING SEDIMENT LADEN RUNOFF CROSS-SECTION OF A PROPERLY INSTALLED STRAW BALE PRACTICE S1319 GENERAL INSTALLATION OF STRAW BALES CITY OF CARLSBAD FN: SIR-BALE [DRAWN BY: CB CHECKED BY: PROJECT NO: 9651135F DATE: 1-28--97 FiGURE NO: S89 WOOD WARD-CLYDE APPENDIIB Details and Standard Specifications STANDARD SPECIFICATION SHEET PROJECT NAME: Harmony Grove Fire, County of San Diego PRACTICE NAME: BM1O Bonded Fiber Matrix DESCRIPTION: A bonded fiber matrix (BFM) is a hydraulically applied erosion control blanket composed of wood fibers held together by a high strength adhesive. Upon cross-linking, the adhesive holds the wood fiber together in a three dimensional matrix which prevents erosion from raindrop splash and overland sheet flow. One of the unique feature of the BFM is that once cross-linked, rewetting of the matrix does not affect the bond strength, and field and laboratory evaluations have shown the matrix to be just as effective in controlling erosion as standard, roll-type erosion control blankets. The BFM is delivered in standard 50-pound bags and is added to hydraulic seeder tank much in the same manner as conventional hydraulic mulch. However, application is somewhat different as the applicator is required to "build a blanket" rather than just spray mulch and seed. In this regard, care must be given to thickness of application and elimination of "shadow effect" during application. The BFM can be used with or without seed. It is straw yellow in color when applied, gradually weathering to an earthen-tone brown over time. A BFM is recommended for use on slopes around high-priority areas, and in general where steep slope conditions and safety concerns preclude the installation of erosion control blankets. WOOdWardCtYdO - W\9651135FECO1-D-R.DOC10-Mar-97\9651135FSDG B-12 APPENDUIB Details and Standard Specifications STANDARD SPECIFICATION SHEET I PROJECT NAME: Harmony Grove Fire, County of San Diego I PRACTICE NAME: EB1 1 Erosion Control Blankets DESCRIPTION: Erosion control blankets (ECBs) are rolled materials which contain plant fibers (straw, coconut I fiber, or wood fiber) held between plastic netting. When used following seeding the ECBs are rolled out in the direction of water flow and held in place using 6-in. x 1 -in. x 6-in, wire staples. I Blankets shall be installed as per manufacturer's guidelines. - ECBs are recommended on those areas where a high velocity water channel requires protection or on steep slopes above existing homes, and then only if access to the site and slope conditions do not pose safety concerns. Another application of the blankets, particularly those made out of 100% coconut fiber, is as I longitudinal filter strips, installed along the contour of a slope in various widths to reduce sheet flow velocities and settle out soil fines and trap ash entering from overland flow. I WOOdWaVd.CIydO W:9651135F\ECO1-D-R.DOC1O-Mar-97\9651135FSDG B43 NOT TO SCALE MATS/BLANKETS SHOULD BE INSTALLED VERTICALLY 4 - DOWNSLOPE. P SOIL OVER MAT BLANKET -- -4Yii -:- a:O• ;J /4 / 4 12 (3o t I, / MIN 4" / (1OOmm) ' / gill OVERLAP / 4 ISOMETRIC VIEW TYPICAL SLOPE SOIL STABLIZATION NOTES: SLOPE SURFACE SHALL BE FREE OF ROCKS, CLODS, STICKS AND CRASS. MATS! BLANKETS SHALL HAVE GOOD SOIL CONTACT. LAY BLANKETS LOOSELY AND STAKE OR STAPLE TO MAINTAIN DIRECT CONTACT WITH THE SOIL. DO NOT STRETCH. PRACTICE EB11 EROSION CONTROL BLANKETS CITY OF CARLSBAD FM: Bt.NKSLP I DRAWN BY: CB I CHECKED BY: I PROJECT NO: 9651135F DATE: 1-28-97 FIGURE NO: EBI 1 WOOD WARD-CLYDE 4 7 (150mm) 12 (300mm). U STAPLES APPENDUIB Details and Standard Specifications STANDARD SPECIFICATION SHEET PROJECT NAME: Harmony Grove Fire, County of San Diego PRACTICE NAME: HS12 Hydraulic Soil Sealing DESCRIPTION: HS 12 is an erosion control practice that can be applied with or without seed. The practice is applied by hydraulic seeding methods and binds the soil surface, ash, seed and mulch together through the use of an acrylic copolymer. The mixture is applied on critical slopes, around foundations, and on off-road sites with limited access to straw-blowing (DM5) equipment. Typically, the HS 12 is a one-step process which includes the following components on a per acre basis: 500 pounds of wood fiber mulch; 1,000 pounds of recycled paper mulch; - Appropriate seed mixture (or no seed mixture); and 55 to 100 gallons of acrylic copolymer, depending on soil conditions. Upon curing, usually Within 24 hours, the mixture forms a crust on the surface which protects the soil and ash from erosion but also allows water to infiltrate. Over time, the crust biodegrades as plants develop. Woodward-Clyde W:9651 135F\ECO1-D-R.DOC1O-Mar-97\9651135F\SDG B-14 APPENDIXB . Details and Standard Specifications' STANDARD SPECIFICATION SHEET PROJECT NAME: Harmony Grove Fire, County of San Diego I PRACTICE NAME: SRi 3 Storm Drain Repair/Modification DESCRIPTION: I Wildfires in vegetated watersheds (both developed and undeveloped) affect hydrology, soil properties, slope stability, and sediment and debris production. The removal of vegetation and heat of the fire can result in hydrophobic soil layers, increased runoff, and increased potential for I . mud and debris flow. Some storm drain systems were damaged during fires and may experience further damage during subsequent storms. The damages include plastic storm drain pipes that were consumed during the fire, clogged inlets, collapsed culverts, overtopped basins and roads, outlet scour and undermining from increased flow. I These damages need to be repaired on a site-specific basis, and modifications to the storm drain system may be necessary to accommodate increased flows and sediment/debris loads. I .. .'. I , I S.S 1 5 5 5' •0 I S S I WOOdWaIdCIydO S W: 651135F\ECO1-D-R.DOC1O-Mar-97'965l 135F\SDG B-15 I S S S APPENDIIB . Details and Standard Specifications STANDARD SPECIFICATION SHEET I PROJECT NAME: Harmony Grove Fire, County of San Diego I PRACTICE NAME: CM14 Channel Repair/Modification DESCRIPTION: I .Wildfires in vegetated watersheds (both developed and undeveloped) affect hydrology, soil properties, slope stability, and sediment and debris production. The removal of vegetation and heat of the fire can result in hydrophobic soil layers, increased runoff, and increased potential for I mud and debris flows. Some existing channels have experienced damage in fires and subsequent storms. These damages are associated with clogging, scour, and overtopping. The damages to existingchannels need to be repaired on a site-specific basis, and modifications to the channels may be necessary to accommodate increased flows and sediment/debris loads. I .. I 0• • . . . I . 1 . .. . . I • •..• I •. ... I I I . . . . . . ii • S .5 WOOdWId.CtydO @ S W9651135F\ECO1-D-R.DOC1O-Mar-97\9651135F\SDG B-16 . I APPENDIXC Site Visits to Localized Areas of Potential Problems After the field work was completed for development of this Plan, two subsequent site visits were I made by our erosion and sediment control specialist with Dick Cook of the City on November 27th and December 16th. The purpose of the site visits was to make a field visit to specific localized areas within the burn area that were of possible concern to the City. I These areas include the following: Gullying behind the residences at 2902 and 2904 Managua Place at two locations A burned slope above an unburned slope in the Alicante Hills area, above Bolero A steep fill slope in the Alicante Hills area west of Bolero along an SDG&E easement that is I exhibiting slumps and significant tension cracks indicating potential slope failure A west-facing slope behind residences along Box Canyon, just above the Arizona crossing I 5. A number of relatively small tributary drainages where the open space in the canyons below the residences was burned, but the homes were generally not burned. I Based on our field assessment and experience, we recommend the following for these areas: 1. The two gullies behind the residences at 2902 and 2904 Managua Place were in existence before the fire due to concentrated runoff being directed onto an extremely steep, erodible I slope. The gullying may be more visible now that the fire has removed the previously-dense vegetation from the slope. The gullying does show signs of widening and deepening since the fire due to increased runoff from the adjacent slopes. I While not posing an immediate threat to public health and safety, we recommend that the City consider installing some gravel bag check dams in both gullies at frequent enough I spacing to slow the velocity of the concentrated flow and trap some sediment behind the check dams. This would be particularly effective on the upper half of the slope before it becomes steeper on the lower slope. We recommend that the abutments of the check dams be I high enough to avoid outflanking, which could result in worse gullying, and that the structures be sturdy enough to avoid overturning failure caused by high flows. We also recommend that care be taken by the workers on the slopes to stay in the proximity of the I existing gullies as much as possible so as to avoid disturbing the rest of the slope and aggravating the slope erosion. I 2. The burned slope area above the unburned slope in the Alicante Hills above Bolero does not appear to present a significant problem. The upper slope is denuded of vegetation and will exhibit higher runoff and sediment loads until it revegetates. The runoff appears to be I primarily sheet flow, and the slope does not exhibit signs of gullying due to concentrated flow. The lower slope is well-vegetated and irrigated, and will act as a filter for the increased runoff and sediment loads. Below the vegetated slope is a street, not residences, so the I impacts of increased sediment-laden runoff would be to the street only, and would most likely require increased street cleanup. I 3. The steep fill slope in the Alicante Hills area along the SDG&E easement that is showing signs of potential failure is a pre-existing condition that was there before the fire. The fire may aggravate the instability to some extent due to increased runoff from unvegetated areas I WOOdWaFd.Clyde & W:9651135F\ECO1-D-R.DOC10-Mar-97\9651135F\SDG CA Li I APPEtIDlIC Site Visits to Localized Areas of Potential Problems that has more opportunity to enter the exposed tension cracks and further reduce the slope's strength. Fortunately, the slope is directly above a street, Bolero, rather than residences. A failure of this slope could result in a considerable volume of soil on the street, limiting ingress/egress for those homes near the end of the cul-de-sac. We recommend that the City notify the homeowners association of the potential problem. The west-facing slope behind residences along Box Canyon just above the Arizona crossing is burned, but not showing imminent hazard to the homes because they are above the slope. This slope will exhibit increased runoff and surficial erosion for the next several years. Due to the rocky nature of the slope and the presence of larger rocks that have been deposited on the slope, there may be some potential for rocks to become dislodged due to increased erosion around the base of the rocks. There are no structures at the base of the slope that would be jeopardized by this occurrence. The dislodged rocks would most likely land in or near the creek bottom. There is a gully below the northernmost home at the top of this slope. The gully pre-existed the fire and is due to concentrated flow being discharged onto the slope, probably from irrigation runoff. This gully may show signs of deepening and widening due to increased runoff from adjacent burned slopes; however, the upper part of the gully near the landscaped property should not worsen because the source 'of runoff from the residential area itself has not increased. The relatively small tributary drainages where the open space in the canyons below the residences was burned, but the homes were generally not burned, exhibit some similar characteristics. The canyons are typically steep, the soils are typically thin and rocky, and there are no structures in the bottoms of the drainages that could be impacted. All of these types of areas will exhibit increased runoff due to the loss of vegetation, and increased sediment loads into the creeks for the next few years. I The placement of temporary check dams in these drainages would serve primarily to trap some sediment and reduce flow velocities. They would not have a significant impact on attenuating peak flows, however. We recommend that the City consider the installation of I check dams in these areas on a case-by-case basis, depending on the relative severity of the problem. I All of the slopes in these drainages are showing signs of natural, revegetation at a rapid rate. The sequence of low intensity storms followed by sunny weather that Carlsbad has experienced since the fire has been ideal for the seeds to germinate and grow. I We also recommend that the City evaluate its storm drain plans to identify utility crossings of the creeks in the burn area. Due to the increased flows and increased scour potential in the I creeks, these utilities may be vulnerable to exposure and damage if they are not adequately buried or otherwise protected. If any such utilities appear to be at risk, we recommend that the City consider the installation of a grade control device at or below the utility crossing to I stabilize the creek invert. I WOOdWard.CIydO 0 W:9651135F\ECO1-D-R, DOC\1O-Mar-979651135F\SDG C-2 I