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Home My WebLink About; Non-Structural Beach Erosion Protection App A; Non-Structural Beach Erosion Protection App A; 1983-06-14NON-STRUCTURAL BEACH EROSION PROTECTION APPENDIX A June 14, 1983 A project of the Department of Public Works and Tidelands Agency City Council Dr. Thomas J. Clark, Mayor Ernie Kell, Vice Mayor Marc A. Wilder Wai 1 ace Edgerton Jan Hall James H. Wi1 son Euni ce N. Sato Edd Tuttle Warren Harwood ENGINEERING DEPT. LIBRARY City of Carlsbad 2075 Us Palmas Drive Carlsbad, CA 92009-4859 City Manager John E. Dever TABLE OF CONTENTS Page INTRODUCTION 1 PROJECT PARTICIPATION 2 SYNTHETIC SEAWEED PLACEMENT 4 SYNTHETIC SEAWEED PLACEMENT DAILY LOG 6 OBSERVATIONS DURING PLACEMENT PERIOD 9 MONITORING PROGRAM OVERVIEW 11 SURVEY OBSERVATIONS 14 ENVIRONMENTAL OBSERVATIONS 26 PROJECT PHOTOS 27 FIGURES 1. Army Corps of Engineers Littoral Environmental Observation Form - 12 2. Monitoring Program Survey Configuration -------------15 3. Beach Survey Range Line 37AA — -._ 15 4. Beach Survey Range Line 38AA ------ — 17 5. Beach Survey Range Line 39AA 18 6. Beach Survey Range Line 40AA 19 7. Beach Survey Range Line 41AA ------------------20 8. Beach Survey Range Line 42AA -21 9. Beach Survey Range Line 43AA -------- — 22 10. Beach Survey Range Line 44AA 23 11. Survey Results, Tabular Comparison Data -------------24 12. 5/18/83 Photo A 28 13. 4/25/83 Photo B-C 29 14. 4/27/83 Photo D-E 30 15. 4/27/83 Photo F-G 31 INTRODUCTION This Appendix A is published as the first of a series to provide information gained from monitoring installation of "Seascape" on the shoreline of East Beach in the City of Long Beach, California. A comprehensive description of the history of erosion problems at East Beach, investigations and measures taken to combat the erosion, factors which led to the decision to make a significant experimental installation of artificial kelp, and the environment of this section of shoreline in Long Beach is contained in the report dated February 28, 1983. The report was submitted to and approved by the City Council on May 3, 1983. The Public Works report on "Non-structural Beach Erosion Protection" described a schedule for publication of a series of appendices to present results of the "Seascape" instal- lation. This Appendix A is the first of the series and covers not only results from the planned monitoring program but information on placement and observations made prior to formal commencement of monitoring. It is presented earlier than originally scheduled (October 1983) because of surprising and rapid changes in the shoreline situation which can only be presumed to have resulted from the "Seascape" installation. PROJECT PARTICIPANTS Many individuals and organizations have contributed to the installation of this large-scale "Seascape" experiment. They deserve recognition since the contribution of each of them in their own unique manner has made the effort substantive and a worthwhile addition to the body of in- formation applicable to beach shoreline protection issues. Most of those individuals are listed below. Alamitos Bay Beach Preservation Association Ted Hokanson Preston Smith Don Utter Butler-Johnson Corporation Mick Kelly Cape Hatteras National Seashore, North Carolina Kent Turner City of Long Beach City Council Member - Jan Hall, District No. 3 City Manager - John E. Dever Planning Department Robert Benard Robert Paternoster - Director Public Works Department James T. Pott - Director Barbara Rechlin Engi neeri ng Bureau Art Andrew Bil1 Berdani s Wm. Doyle Bowers, Manager - Engineering Rich Boyce Richard Cook Leon Duhamel James Evans Mark Farestveit Gilbert Goodwi n Fred Gravell Floyd Greene Ernie Hott Lloyd Jenkins «,, Bruce Johnson Lon Maddox «* Edmund Miller David Mitchellm . Janet Mul1i ns * James Murray Ralf Nilsen „ Ken Phillips Dave Obert """ Steve Riley Jim Stei n * Helene Tate <MI Public Service Bureau t*» Don Claunch *" John Beer ^ Harry Erickson ** Gary Lowe M Dick Tedford Richard Zack, Manager - Public Service <•! Tidelands Agency Grant Abrahamson Mark Boone * Bill Forrester Don Grant * Ualt Halverson, Richard Miller, Manager - Marine Bureau Allan Miki „ Gil Moxley Jim Rae '** Bi rch Parker Carolyn Sutter, General Manager "* Wi 11 i am Ward a*County of Humbolt Guy F. Kulstad, Director of Public Works* Isle of Palms Beach and Racquet Club, South Carolina•«• m DavidStevens «, U. S. Army Corps of Engineers, Los Angeles Districct " Robert M. Clancy * Wilmette Park District, Illinois — Raymond A. Van De Walle, Director SYNTHETIC SEAWEED PLACEMENT Contours of the beach and the submerged foreslope were derived from field data before beach fill began, after initial dredging and following final dredge fill placement on April 21, 1983. Elevation information is provided after both dredging episodes due to significant lapse of time and the storm which occurred prior to final placement of beach fill. Placement began on April 25, Monday, in the vicinity of 69th Place and moved toward the west following the rough elevation -6.0 (MLLW) contour established by survey bottom soundings. "Seascape" (synthetic seaweed) units were filled at the Marine Maintenance Yard by Marine Bureau personnel. Fill sand was trucked to the yard. A frame was rigged to be supported on the side of the truck. The top of a plastic pile protection cap was cut off, inverted, and placed in the frame. "Seascape" units were hand held beneath the tip of the cone while the anchor tube was filled approximately one-half full. Upon completion of filling, the open end of the anchor tube was twisted, doubled over, and secured with an electrical cable tie. It was then placed on a pallet ready for loading onto the dredge crew work boat. Units weighed about 60 pounds each. The work boat delivered units to the dredge anchored offshore of East Beach where units were restacked on each side of the dredge and on one end. City dredge "R.E.K." was used for initial placement since its winch and anchor system permitted more precise locational con- trol to follow the curving alignment of the elevation -6.0 (MLLW) contour previously marked by buoys. Units were dumped off each side of the 25 ft. wide dredge. As the dredge moved to its next position, more units were dumped off of the end. The exercise permitted concurrent placement of the three rows recommended by Beach Builders of California at approximately the recommended 10 ft. spacing. Divers adjusted the units on the bottom. It was found that, since placement took place in relatively calm water (activity was confined essentially to the morning hours because of surf conditions and the draft of the dredge), there were no significant roll- ing or twisting of the units requiring adjustment. Placement continued through Thursday, April 28th, at rates varying from 150 units the first day to 300 units the fourth day. By Friday morning, April 29th, placement had been com- pleted westerly to roughly midway between 62nd Place and 63rd Place. Tide and surf conditions then interrupted placement until Tuesday May 3, when placement resumed. Placement of standard "Seascape" units between 63rd and 58th Place was completed on Friday, May 6. Additional experimental units of "super kelp" fabricated from 3-ft. unslit solid poly- ethylene sheets with ball flotation commenced on May 7 and the 100 units were fully installed that day. This "super-kelp" was placed on the oceanside of the i^gular rows at the mouth of a submerged valley between 65th Place and 63rd Place. SYNTHETIC SEAWEED PLACEMENT DAILY LOG April 25, 1983, Monday Weather - Clear Surf - Calm CREW AND EQUIPMENT Marine Department - 8 men, Lifeguard boat, barge P.S. Sewer Maintenance, Dredge operator, 3 men, tender, 2 dump trucks , dozer Engineering Survey Section - 4 men, survey boat WORK PERFORMED Seaweed placed from midway between 69th and 70th Place to 69th Place, about 200 feet. Placement stopped at noon, each day, because of afternoon winds. April 26. 1983, Tuesday Weather - Clear Surf - Calm to 1 i ght chop CREW AND EQUIPMENT Same as above WORK PERFORMED Seaweed placed to midway between 67th and 68th Place about 300 LF. Divers notice that the weighting tube portion of previously laid seaweed is covered. April 27, 1983, Wednesday Weather - Cloudy Surf - light to med. CREW AND EQUIPMENT Marine Department - same as above P.S. Sewer Maintenance, Dredge Operator, Same as above Survey - 4 man crew, beach work only WORK PERFORMED Seaweed placed to 65th Place, about 500' along beach. Total logged length of seaweed placed is 1170 feet. SYNTHETIC SEAWEED PLACEMENT (cont.) April 28, 1983, Thursday Weather - Cloudy Surf - Medium CREW AND EQUIPMENT Same as above WORK PERFORMED Began placement of seaweed along sand bar left by replenish- ment project; seaweed placed to midway between 62nd and 63rd Place, about 500 feet parallel to boardwalk. Some of the seaweed ended up in approximately 4-1/2 feet of water. April 29, 1983, Friday Weather - Rain Surf - Heavy No Work Today Between 62nd and 65th Place, only 18" of seaweed tops found exposed. Elsewhere, weighting tubes of seaweed found buried. April 30 - May 2, 1983. Saturday through Monday No work - storm conditions Weather - Rain, Cloudy Surf - Heavy May 3, 1983. Tuesday Weather - Cloudy, Windy CREW AND EQUIPMENT Mari ne Department - 8 men, Lifeguard boat, barge P.S. Sewer Maintenance, Dredge Operations - 3 men, dredge, tender, 2 dump trucks, dozer Survey Section - 4 men, boat WORK PERFORMED Dredge moved back in after weekend storm. Seaweed placed from 63rd Place to 62nd Place, about 200 feet. May 4. 1983, Wednesday Weather - Cloudy, Windy Surf - Medium CREW AND EQUIPMENT - Same as above WORK PERFORMED Placed seaweed from 62nd Place to 60th Place, about 400 feet. Seaweed from previous day found buried about 2 feet. Don Claunch Dredgemaster, theorizes that this sand may be from the sand bar ,1 SYNTHETIC SEAWEED PLACEMENT (cont.) May 4, 1983 (continued) formed during the replenishment project. That sand bar appears to be flattening from its original profile. Some 10 to 15 units were found washed ashore, presumably by the weekend storm, but all other units appear to be okay, other than occasional fronds torn off during installation. May 5. 1983, Thursday Weather - Cloudy, Windy Surf - Medium CREW AND EQUIPMENT Same as above WORK PERFORMED Placed seaweed from 60th Place to 59th Place, about 200 feet. May 6, 1983. Friday Weather - Cloudy, Windy Surf - Medium CREW AND EQUIPMENT Same as above WORK PERFORMED Completed placement of regular seaweed. Seaweed placed between 59th Place and 1/3 block short of 58th Place, about 150 feet. May 7, 1983. Saturday Weather - Clear, Sunny Surf - light CREW AND EQUIPMENT Same as above WORK PERFORMED Began and completed installation of "Super Seaweed". "Super Seaweed" placed between 65th Place and 1/2 block short of 63rd Place, about 300 feet. OBSERVATIONS DURING PLACEMENT PERIOD By 3:30 pm. Tuesday, April 26, reports were received that the anchor tubes of units placed on Monday were being covered with fine sand. The bottom conditions were described as very turbid. By Wednesday, placement had extended west to 65th Place. Sand was still building up on those put in Monday but rather slowly. There was considerable turbidity in the immediate vicinity of the kelp field. In the vicinity of 65th Place, sand is co^ser (this was primary area of emphasis for the second dredged fill- ing). Bottom buildup with this coarser sand was more rapid and divers could see sand settling around the fronds. Divers reported that they knew when they were in the vicinity of the kelp field due to the increase in turbidity around the kelp units. Due to very irregular bottom elevations, portions of the kelp "line" in the vicinity of 65th Place were placed at water depths of approaching 4-5 feet (MLLW). It was reported that sand precipitation was particularly rapid in these shallower depths. During early stages of placement, "Seascape" fronds were torn loose and floated onto the beach. Inspection revealed that loss of fronds was due to handling damage. No cutting action on the Typar fabric was observable. Some whole units of "Seascape" washed ashore in the vicinity of 65th Place. Two of the units were carried ashore by the buoys to which they had been secured. Other units (about 5) were washed ashore undamaged. Examination revealed that the open end of the anchor tube was still secured and that there were no penetrations of the anchor tube. All fronds were intact. The anchor tube, however, was only about 1/3 filled. It appears that care must be taken not only to avoid overfill- ing but also to avoid underfilling. Small changes in anchor tube diameter may account for the problem. For other instal- lations, care is recommended to insure that the anchor tube is filled and loosely shaken to make sure that the tube is between 1/2 and 2/3 full in the dry condition. By the end of the week, divers reported that some of the units were buried so that only about 18" -24" of frond were showing. Beach observation on Sunday May 1st at tide elevation 3.0 (MLLW) and wind from the SSW of about 20 knots revealed a noticeable flattened beach foreslope in those sections where the "Seascape" had already been placed offshore. West of 62nd Place, the foreslope is significantly steeper with high energy runup and probable continuing loss of beach fills placed by the dredging operation. Care was taken in the completion of the "Seascape" line to rediscover the -6.0 (MLLW) contour. Seaweed placement was completed May 7. Additional observations were made as part of the Maintenance Program, the results of which are reported hereafter. 10 MONITORING PROGRAM OVERVIEW The City has pursued a comprehensive monitoring program as indicated in the main report. Improvements have been made to the program from the outline described in the main report, which improvements have been timely considering the quickness of significant results. Improvements that have been made are: 1. The first post-installation survey was performed three weeks after the beginning installation, rather than the three months as initially planned. The next survey is currently scheduled for August, 1983. 2. Underwater inspection of the seaweed was performed during and after installation. The next underwater inspection will coincide with the next survey in August, 1983. 3. The daily wave observations have been expanded as a part of the establishment of an Army Corps of Engineers "Littoral Environment Observation (LEO)" station for the East Beach area. Observations have been made daily on Standard LEO forms which cover a complete set of beach characteristics. An observation form showing character- istics observed is attached. (Figures 1, A & B). These have been and will be transmitted to the Army Corps of Engineers on a monthly basis, with copies retained by the City for local analysis. 4. While not specified in the main report, the Engineering Bureau is maintaining a complete photo log on the project. Various recent photos are included in this addendum. 11 ARMY CORPS OF ENGR. STANDARD FORM LITTORAL ENVIRONMENT OBSERVATIONS RECORD ALL DATA CAREFULLY AND LEGIBLY SITE NUMBERS 12345 MONTH 8 DAY 10 II Record time using the 24 hour system TIME 12 13 14 15 WAVE PERIOD Record the time in seconds for eleven (II) wave crests to pass a stationary point. If calm record 0. 16 17 IB BREAKER HEIGHT Record the best estimate of the average wave height to the nearest tenth of a foot. 19 20 21 D WAVE ANGLE AT BREAKER Record to the nearest degree the direction the waves are coming from using the protractor on the reverse side. 0 if calm. WAVE TYPE 0- Calm 1 - Spilling 2 - Plunging 25 3 - Surging 4- Spill/Plunge WIND SPEED Record wind speed to the nearest mph. If calm record 0. 26 27 WINDWIIVU I-N 3-E 5-S 2-NE 4-SE 6-SW 8-NW Direction the wind is coming from. 7-W 0-Calm 28 FORESHORE SLOPE Record foreshore slope to the nearest degree. WIDTH OF SURF ZONE Estimate in feet the distance from shore to breakers, if calm record 0. 31 32 33 34 LONGSHORE CURRENT CURRENT SPEED Measure in feet the distance the dye patch is observed to move during a one (I' minute period; If no longshore movement record 0. 43 44 43 DYE Estimate distance in feet from shoreline to point of dye injection. CURRENT DIRECTION 0 No longshore movement + I Dye moves toward right - I Dye moves toward left 36 37 38 46 47 RIP CURRENTS If rip currents are present, indicate spacing (feet). If spacing is irregular estimate average spacing. If no rips record 0. 49 50 51 52 BEACH CUSPS If cusps are present, indicate spacing (feet). If spacing is irregular estimate average spacing. If no cusps record 0. 54 55 56 PLEASE PRINT: SITE NAME OBSERVER Please Check The Form For Completeness REMARKS: CERC 113-72 8 Mar 72 Make any additional remarks, computations or sketches on fhe reverse side of this form. 12 FIGURE 1A ti *iiii)i»ijiik ti t * ti G» 3 rm.m 11 si OCEAN 60 20 50 30 40 140 30 SHORELINE • SHORELINE OBSERVER NOTE: If a pier is used for on observation platform: place 0- ISO line on the rail parallel to the centerline of the pier, site along the crest of the breaking waves and record the angle observed. 150 160 180 SURVEY OBSERVATIONS The following figures show the results of collected survey data. Figure 2 shows the established survey range line configuration with contours plotted from the latest survey. Figures 3 to 10, computer drawn sections, show the various beach profiles determined by the following surveys: 1. Survey 11/3/82, showing initial beach before commencement of dredge contract. 2. Survey 2/28/83, sho.wing beach during interruption of dredgi ng. 3. Survey 4/21/83, showing beach configuration following final dredge operation and immediately prior to seaweed piacement. 4. Survey 5/20/83, showing latest monitoring program survey results. Figure 11 (A and B) shows comparison data which are established as a simplified, objective means of determining the status of the seaweed installation. 14 if t * • i it ii ij it i * § *ti t en O. inin 0. Z D O OCEAN BLVD \9in <0in n: Ovfl D Z CM vS Q. I- vfl vfl Q. IT h- a.a. Qz (\J N SCA.SVCC EMIMA.T16.D LOCATIO SURVtV RANGE LINIt JETTY • FIRST POST-INSTALLATION SURVEY, 5-2O-« EAST BEACM ARTIFICIAL SEAWEED INSTALLATION MOMITOR1NG PROGRAM SURVEY CONFIGURATION FIGURE 2 li ii i i • i ti i j t > i i ti ti * < t i i i 15 IT 5 0 -5 -10 -15 -20 \ HIGHEST OBSERVED TIDt LEGEN D -5/20/83 Latest survey results LOWER LOW Range Line 37AA Horiz. Scale: 100 ft/in Vert Scale: 10 ft/in FIGURE 3 ti At ti i j I i ti It ti if ii ia i ii i * i 15 ^^ 10 5 0 -5 -10 -15 -20 CSII § 4- co WGWE.ST OBSERVED TIDE LE.GEN1D -5/20/83 Latest survey results LONX/E.R LOW WAJE Range Line 38AA Horiz. Scale: 100 ft/to Vert Scale: 10 ft/in FIGURE 4 tl ti tJ ti i i i i i ti it it II i * t * * *4 I WIGUEST OBSE.RVE.D TIDE LEGEND 1V4/82 Beach before dredging. 2/25/83 Beach at dredge interruption. 4/21/83 Beach after dredging/before seaweed installation 5/20/83 Latest survey results LOWE.R LOW WkTER SEAWEED (? LOCATION)-- Range Line 39AA Horiz. Scale: 100 ft/in Vert. Scale: 10 ft/in o + CM FIGURE 5 A I i i i I t i t i ii i j i j ii II i J ii li ta At 15 10 5 0 -5 -10 -15 -20 installation LEGEND 11/4/82 Beach before dredging. 2/25/83 Beach at dredge interruption. 4/21/83 Beach after dredging/before seaweed 5/20/83 Latest survey results 5 £ A WE tD(? LOCATION) Range Line 40AA Horiz. Scale: 100 ft/in Vert Scale: 10 ft/in CNJ I CO o + u> FIGURE 6 ti i I ft i «ti ti i i ii t * I ti ti roo 15 10 5 0 -5 -10 -15 -20 installation LEGEND 1V4/82 Beach before dredging. 2/25/83 Beach at dredge interruption. 4/21/83 Beach after dredging/before seaweed 5/20/83 Latest survey results Range Line 41AA Horiz. Scale: 100 ft/in Vert Scale: 10 ft/in FIGURE 7 it fi ti ti If t * ** * ro 15 10 5 0 -5 -10 -15 -20 CXI CM CO C0 FIGURE 8 li ti i * ii li fci J l i ii ii ii « * * to LE.GEMD 1V4/82 Beach before dredging. 2/25/83 Beach at dredge interruption. 4/P1/83 Beach after dredging/before seaweed S/PQ/83 Latest survey results 5EKWE.ED(? HORIZ. LOCATION).. Range Line 43AA Horiz. Scale: 100 ft/in Vert Scale: 10 ft/in CO FIGURE 9 ti 11 ti ti li ti * * • » » »iiia t * * row 15 10 5 0 -5 -10 -15 -20 ^r OBSERVED TIDE LEGEKJD -4/21/83 Beach after dredging/before seaweed instaUation -5/PO/83 Latest survey results LOWER LOW W Range Une 44AA Horiz. Scale: 100 ft/in Vert. Scale: 10 ft/in KTER CMI CO FIGURE 10 SURVEY RESULTS Tabular Comparison Data A. Location of -6 ft. (MLLW) contour - original bottom elevation at artificial seaweed location. UJcc3o Range Line No. 37AA 38AA 39AA 40AA 41AA 42AA 43AA 44AA Distance from Survey Base Line, feet 4/21/833 .2 .2 363 513 401 367_2 650 5/20/834 377 344 360 410 470 400 419 600 (8/83)1 _ _ _ -_ _ - 1 Scheduled3 Prei nstal lation Data unavailable Monitoring Program Surey B. Comparison beach volumes - see accompanying drawing for section limits. Range Line Lmits Volume, Cubic Yards 4/21/83 5/20/83 (8/83)1 39AA to 44AA 262,685 280,324 37AA to 44AA -2 425,000 24 ti t • * «ii li if il • i ii li i i •• 10at 10- oo COMPARISON DATA TYPICAL SECTION TABULATED VOLUME MIKJGE. POIKT oo oo HIGHEST OBSERVED TIDE. MEAN LOWER LOW WATER LOCATION OF-6.0' ELEVATION TABULATED DISTANCE FIGURE 11B ENVIRONMENTAL OBSERVATIONS Environmental observations were of two kinds: monthly diving inspections and daily site observations. The diving inspections, were made regularly throughout the installation period and afterward. Significant findings have been transmitted verbally to the Bureau of Engineering, with permanent records kept in the form of standard diving logs. The findings of the diving inspections have been described previously in this appendix, with no other changes to the installation observed as of the date of this appendix. Daily site observations were begun April 11, and have been recorded on Army Corps of Engineers "Littoral Environment Observation (LEO)" forms. The LEO program is a cooperative program administered by the Corps of Engineers, where volunteer agencies record local data as shown on the form, including such types of information as wave height and period and estimated longshore current. The information is trans- mitted to the Corps of Engineers, which will make annual computer analyses and reports. The City of Long Beach has retained copies of all submitted information for immediate localanalysis. For the period covered by this report, April to June, typical site conditions have been observed at 2:30 p.m. each day with reasonable consistency to establish a time of day for com- parison purposes. Typical waves have been less than 1-1/2 feet with periods of around 10 seconds between waves. The typical wind has been 10 mph out of southwest. The prevailing longshore current ran west to east, one day at a reported speed of 120 feet per minute but generally calm. A small storm (severe enough to halt seaweed installation) struck the area April 28 to May 3. Wave heights reached a maximum height of 2-1/2 feet, but wind speed and direction remained fairly consistent with non-storm conditions. 26 PROJECT PHOTOGRAPHS 27 J,^ • ' •» FIGURE 12 PHOTO A May 18.1983 Post-installation beach overview. Photo taken at altitude 1000 ft. with tide at -0.4 ft.. MLLW. 28 eo PHOTO B April 25, 1983: Artificial Seaweed Unit UJcc D O LL PHOTO C April 25, 1983: Sand filling apparatus,, The funnel is a pile cap, inverted, with the tip sawed offv 29 UJ (£ PHOTO D April 27, 1983: Seaweed units placed on barge for transport to installation site,, ^»^^,^ . .^ ^^....Ljam..^^^^ PHOTO E April 27, 1983:The City Dredge "RUEUKU" in place at the installation site, ready for seaweed placement. The dredge boom is down to improve the anchorage of the dredgeu 30 i 10 LUo: Dg U- PHOTO F April 27, 1983: Artificial Seaweed released into the water. PHOTO G April 27, 1983:Artificial Seaweed released into the water Note the orange buoys used by divers for final Seaweed positioning. 31