Me U.S. Army eae Coast Eng, — (i Res cw dD MP 3-74 Bolinas Lagoon Inlet, California. : : J.W. Johnson Hydraulic Engineering Laborato University of California Berkeley, Calif. 94720 MISCELLANEOUS PAPER No. 3-74 MAY 1974 Approved for public release; distribution unlimited Prepared for U.S. ARMY, CORPS OF ENGINEERS _ COASTAL ENGINEERING RESEARCH CENTER Kingman Building Fort Belvoir, Va. 22060 material shall give appropriate ng Research Center. yrint or republication of credit to the U.S. Army Coastal Engineeri Limited free distribution within the United States of single copies of b on has been made by this Center. Additional copies are available from: G PDA 735 747) National Technical Information Service ATTN: Operations Division 5285 Port Royal Road Springfield, Virginia 22151 The findings in this report are not to be construed as an official Department of the Army position unless so designated by other uthorized documents. SSN — SECURITY CLASSIFICATION OF THIS PAGE (When Data Entered) READ INSTRUCTIONS REPORT DOCUMENTATION PAGE BEFORE COMPLETING FORM T. REPORT NUMBER 2. GOVT ACCESSION NO. 3. RECIPIENT'S CATALOG NUMBER MP 3-74 4. TITLE (and Subtitle) 5. TYPE OF REPORT & PERIOD COVERED Miscellaneous Paper BOLINAS LAGOON INLET, CALIFORNIA 6. PERFORMING ORG. REPORT NUMBER HEL 24-15 7. AUTHOR(S) 8. CONTRACT OR GRANT NUMBER(S) J. W. Johnson 9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT, PROJECT, TASK AREA & WORK UNIT NUMBERS Hydraulic Engineering Laboratory University of California 04-2001 Berkeley, California 94720 11. CONTROLLING OFFICE NAME AND ADDRESS 12. REPORT DATE Coastal Engineering Research Center 13. NUMBER OF PAGES Kingman Building, Fort Belvoir, Virginia 22060 46 14. MONITORING AGENCY NAME & ADDRESS(if different from Controlling Office) | 15. SECURITY CLASS. (of thle report) Unclassified 15a. DECLASSIFICATION/ DOWNGRADING SCHEDULE 16. DISTRIBUTION STATEMENT (of this Report) Approved for public release; distribution unlimited 17. DISTRIBUTION STATEMENT (of the abstract entered in Block 20, if different from Report) 18. SUPPLEMENTARY NOTES 19. KEY WORDS (Continue on reverse side if necessary and identify by block number) Tidal Inlets Waves Tidal Prism Littoral Drift Hy draulic Engineering Bolinas Bay Lagoons California 20. ABSTRACT (Continue on reverse side if necesaary and identify by block number) The hydraulic and sedimentary characteristics of tidal inlets on sandy coasts have long been of interest to engineers involved in harbor design and maintenance. O’Brien (1931), in a study of west coast inlets, proposed a relationship between the minimum inlet area below mean sea level and the tidal prism. Other investigators in recent years have proposed similar relationships. A reanalysis of data from inlets on U.S. coasts by O’Brien (1967), resulted in a later observation (O’Brien, 1971); he believed that the equilibrium relationship between inlet area and tidal prism as he originally proposed seemed to be a first approximation only and that the next effort should be for quantative understanding of deviations from the approximation. If the flow area is determined by the tidal prism, Continued DD , Fes 1473. ~— EDITION OF 1 NOV 65 IS OBSOLETE UNCLASSIFIED eee SECURITY CLASSIFICATION OF THIS PAGE (When Data Entered) UCL SS SECURITY CLASSIFICATION OF THIS PAGE(When Data Entered) then this area is in constant process of adjustment because the tide range, and the related tidal prism, varies continually. The Bolinas Bay-Bolinas Lagoon system is a natural laboratory in which a large amount of data has been compiled on hydrography, wave action, tidal hydraulics, sediment transport and sedimentation, and the ecosystem. However, the data are insufficient to adequately define the importance of the inlet area and tidal prism. The source, nature, and availability of data on the Bolinas Lagoon inlet are summarized as a guide to possible future studies at Bolinas, and at other inlets. UNCLASSIFIED SECURITY CLASSIFICATION OF THIS PAGE(When Data Entered) PREFACE CERC is publishing this report because of its interest and value to coastal engineers. This report was prepared by J. W. Johnson, Hydraulic Engineering Laboratory, College of Engineering, University of California, Berkeley. Work was completed during the author’s sabbatical-leave studies in the fall and winter quarters, 1972-73. NOTE: Comments on this publication are invited. Approved for publication in accordance with Public Law 166, 79h Congress, approved 31 July 1954, as supplemented by Public Law 172, 88¢/ Congress, approved 7 November 1963. JAMES L. TRAY Colonel, Corps of Commander and Director gineers Po ee © a. ete ee as me ae 2 : : fi jie «ta is Nyssa gh _ IER hat a : é ia al Nc RT's SOT anced Taba cop iy , Sellehoicl 9 > tiene CONTENTS FUN TRO DUCTION or ais. Ua ci aks Sede aay otto ihcs nitoo ie Nes Venaducels den Sontitkahyes If NATURE AND SOURCES OF BASIC DATA .................. Ii IV Ne Cerrerall cn aont eesaea rie sien ooo rae eich Pogicbhe MOG tere iiomeietey coca rate 5, Longshore; @urrentswism-aer kee iey tek CIR ete Raz) SOO. BIE Weenies 5 LTO IRN OCIA Gb a aerate: bk cwenpkdewis NoWanianondhs vos onineaaegeh od sir MER OLLOMSCCIIMENtS meee tte ee era ee eae mete ee ee ee Re ea Sebidalselatonshipsie tebe ecto tears as iloghceled io Cech SEC gh caine spew erecta Se) 6) A ey Gy &S Bo f9 OURVEeY Ss OlsbeachesanayDOtlOmy gn. ee ioe eerie) ERT apne ne NOSeMidallPrisme pots, Satoh Gel wie bs ots ey Rae ies AS se HMR HidalkCurrentse® oye tess AW Dee BESO SRN ee PPR ita 12. Sediment Transport in Bolinas Lagoon Inlet ................ Ade, PNEMCOSYSLCTN Hs hh. 151 SRNL ALLEN SUNS MYCE Te Bak ARE ORE. AEN INCU L EG, SUMMARY OF DATA RELEVANT TO THE INLET .............. lesWaverDatad cyt. ashe eS ue. Buti Dei ie v ADR yee Sy SRNATD eRe viWiaverPowelsy sings, Qe hae Misneited, WA save gh HRS ealLoneshoresCurrentsmemn net eter eee ee Pe ee ce en ee Teeter eae eeSedimentatronskrocesses—bolinas) Day wet nie) mei es alee pelrtle ta Ghana cteristics weeny suet Le ce ea ee cee panes soa en ey Nn P w hy TABLES Corps of Engineers Refraction Diagrams for the Central California Coast Tidal Differences—Bolinas Bay and Bolinas Lagoon ............... nicl al cat ante beesa Oy HP C6 od oles ln carnal uate il econ ai Skis V2, Ne! Sas Westen mB whe CONTENTS—Continued FIGURES Vicinitysmap.centrali@alikorniaicoasts sacra cee cueencn en Can mer an mca: Searand!swellirosesawestot GoldeniGatem-ararue rain ane ee ee Wavejretractionidracramin seu cn Woe ener aCe ee ee ee ee ee Location of bottom surveys, beach ranges, beach observation sites, and wave cagein Bolinas/Bays ©.a.8. "neuen sn token mene mene ome Deepwater wave power (sea and swell) for various months at Station No. 3, Cahfornmiascoast: (0s. aug Saleosiie ds hare ee et oN ae Wave power for Station No. 3 (California coast) compared with beach observations at Stinson Beach and Bolinas Bay ................. Five-day moving averages of wave power from observations at Stinson Beach, BolinastBayz.and the Bolinasswave casey sary nein ncn aren nena nme meme Wave period and longshore currents, Stinson Beach State Park and Bolinas, Galifornia, 1968269" voces ese lot een ne a ee ee Areas of scour and fill between 21 August 1968, and 19 December 1968 Comparison of Bolinas Bay bottom contour maps of 17 May 1968, andi 16: May NO G9h ss. aie ce Gas renee cave seen a yer een eee Seasonal variation of the position of the mean high tide line, Stinson Beach spit, TOA =VOTO: pdb vas dls cess wae hale Hera he Sooke Ral ce Day-to-day variation over a 4-month period of the horizontal distance from a reference point on shore to various beach contours, Stinson Beach spit, Galifornia e255." es ag en oe eee ect eR dal A Aerial vertical photo of Bolinas Lagoon inlet on 1 April 1945... ....... Aerial vertical photo of Bolinas Lagoon inlet on 31 August 1948 ........ Aerial vertical photo of Bolinas Lagoon inlet on 15 September 1959 ....... Aerial vertical photo of Bolinas Lagoon inlet on 10 November 1959 ....... Aerial vertical photo of Bolinas Lagoon inlet on 24 May 1961 .......... Aerial vertical photo of Bolinas Lagoon inlet on 19 June 1962 .......... Aerial vertical photo of Bolinas Lagoon inlet on 17 May 1968 .......... Aerial vertical photo of Bolinas Lagoon inlet on 9 November 1969 ....... Throat sections at Bolinas Lagoon inlet from U.S. Geological Survey tidalimeasurementsts cue) canis) a eC en ee BOLINAS LAGOON INLET, CALIFORNIA by J. W. Johnson I. INTRODUCTION The hydraulic and sedimentary characteristics of tidal inlets on sandy coasts have long been of interest to engineers involved in harbor design and maintenance. It was not until 1928, however, that E. 1. Brown (1928) expressed the hydraulic conditions at an inlet in a rational manner and discussed in general terms some of the sedimentary problems. Later M. P. O’Brien (1931) made a study of west coast inlets and proposed a relationship between the minimum inlet area below mean-sea-level and the tidal prism. Several investigators (Brunn and Gerritsen, 1960; Wiegel, 1964; Frautschy and Inman, 1954; Inman and Frautschy, 1965), in recent years, used data from inlets on many sandy coastlines and proposed relationships between inlet area and tidal prism, but all of these relationships agree relatively closely with that of O’Brien (1931). Recently O’Brien (1967) reanalyzed all available data from inlets on the west, east, and gulf coasts of the United States, and proposed a relationship which was accurate, between +10 percent in flow area and +15 percent in tidal prism. O’Brien (1971) later observed that the relationship seemed questionable since, (a) there appeared to be no effect of the size of sand forming the channel and adjacent shores, (b) the range of tide enters only as it affects the tidal prism, (c) the net and gross rate of transport of littoral drift is not effective, (d) both unimproved and improved inlets are included, (e) lagoons with two inlets conformed if the summation of the flow areas was used, (f) the inlets to both lagoons and estuaries followed the same relationship, and (g) there appears to be no effect of freshwater flow or of sediment transport. O’Brien (1971) further stated that he found it difficult to visualize how it is possible that these influences would be completely ineffective in altering the throat area. He believed that the equilibrium relationship between inlet area and tidal prism as he proposed would seem to be a first approximation only, and that the next effort should be directed towards quantative understanding of deviations from it. If the flow area is determined by the tidal prism, it would follow that this area is in a constant process of adjustment, because the tide range, and the related tidal prism, varies continually. To adequately define the importance of the variables involved in the hydraulic and sedimentary characteristics of inlets on sandy shorelines, data are necessary on such items as (a) simultaneous tides in the ocean and in the lagoon, (b) bottom changes of the inlet throughout the year, (c) friction losses, and (d) bottom sediment size distribution and sand waves. Such data are difficult, expensive, and often hazardous to obtain. Bolinas Lagoon inlet is a natural laboratory in which a large amount of data has been collected over the yeats—perhaps more than for any other lagoon in existence. Even then, the data are insufficient to define adequately the importance of the variables involved in the relationships discussed above. However, the source, nature, and availability of data on the Bolinas Lagoon inlet are summarized here as a guide to possible future desirable studies at Bolinas and at other inlets. Il. NATURE AND SOURCES OF BASIC DATA 1. General. Bolinas Lagoon, 1,100 acres in area and located in Marin County about 15 miles northwest of San Francisco, is separated from the ocean (Bolinas Bay) by a long sand spit. (See Figures 1 and 4.) In 1956, the Bolinas Harbor District was formed to investigate the possibility of establishing a harbor of refuge in Bolinas Lagoon. In 1966, Norman T. Gilroy and Associates were engaged to coordinate, implement, and report on a multidisciplinary program of study and research into the natural environmental systems of the lagoon and its watershed, designed as the first step for planning the long-term conservation and use of the region and the lagoon. The natural environment of Bolinas Lagoon was analyzed in three fundamental segments—the watershed, the system of natural dynamics of Bolinas Lagoon and Bolinas Bay, and the ecosystem. The scope of these various studies has been published by Gilroy (1970a, 1970b). For the watershed studies, the U.S. Geological Survey (USGS), in cooperation with the Bolinas Harbor District, began an investigation of the hydraulic and sedimentation characteristics of the lagoon to provide information on: the freshwater inflow into the lagoon, the quantity of fluvial sediment transported into the lagoon, the quantity of sediment transported into and out of the lagoon through the tidal inlet, the direction of littoral transport near the inlet, the circulation of water within the lagoon, the bottom topography, and the sediment movement within the lagoon. Some of the data from these studies have been published by Ritter (1969). Not all of these data, however, relate to the inlet itself, but where the data are pertinent to this report a summary is presented at the appropriate place below. Of particular importance to the sedimentation problem in Bolinas Lagoon is the following comment by Ritter (1969): “Lagoons are temporary features along a coast. A generalized history of a lagoon may begin with a river mouth drowned by a rising sea level. Littoral drift creates a spit or barrier bar across the mouth so that its access to the ocean is restricted to a narrow inlet. The lagoon begins to fill with sediment and becomes a tidal flat with channels carrying much of the tidal water. The filling continues until the lagoon becomes a salt marsh as vegetation grows on the rising tidal flats. Eventually, the lagoon becomes a flat plain that may be eroded by waves lapping against its seaward edge. The life of a lagoon depends on the rate at which sediment is entrapped in the lagoon. Bolinas Lagoon, the seaward end of a rift valley created by the San Andreas Fault, is now probably in the stage of a tidal flat that is becoming a salt marsh.” Bodego San Pablo Bay Duxbury Point Bolinos Bay Francisco a SAVE SvAnION Woe 37.6°N, 123,5°w Par Sannecso Montara PI. Pillar Point (0) 10 miles Ieee ee Half Moon Boy Miramontes Pt Figure 1. Vicinity map, central California coast. (Johnson, 1965.) This item about Bolinas Lagoon becoming a salt marsh is ecologically important. As Ritter (1969) points out, Bolinas Lagoon is now a recreation area used for clamming, fishing, boating, nature studies, bird watching, and other saltwater-oriented uses. However, and probably overlooked by those most active in striving to maintain the lagoon in its present natural state, the inlet may close completely long before sedimentation has reduced the lagoon to a salt marsh, the environment will shift in a few years from a saltwater lagoon to a brackish or possibly freshwater lagoon. Examples of closed lagoons in this general area are Abbotts and Rodeo Lagoons. To appraise the sedimentation processes at the Bolinas Lagoon inlet requires information such as: repeat bottom and beach face surveys at frequent time intervals, aerial photographs, wave data, littoral-current data, tide and tidal current data, and the physical properties of bottom and beach sediments. A summary of the nature, extent and availability of these various data follows: 1. Hydrographic surveys by the U.S. Coast and Geodetic Survey (USC&GS) were made in Bolinas Bay as follows: Chart No. Date Scale H-438 1854 1:10,000 H-456 1855 1:20,000 H-721 1858—60 1:100,000 H-4975 1919 1:20,000 2. Hydrographic surveys along the northern part of Bolinas Bay near the mouth of Bolinas Lagoon were made by R. M. Towill Corp. for the Bolinas Harbor District at a scale of 1 inch = 200 feet on the following dates (Gilroy, 1970a, App. No. 3): 17 May, 21 Aug., 19 Dec. 1968; 15 Apr., and 16 May 1969. 3. Beach profiles along three ranges on the Stinson spit were surveyed on several occasions by Trask (1959), and Trask and Snow (1961) of the University of California. (See Figure 4.) 4. Beach profiles along five ranges on the Stinson spit were surveyed by the Corps of Engineers (1965) in March and August 1961. The same well-referenced ranges were resurveyed in March and April 1969 by the California State Lands Division (1970). 5. A range across the Stinson spit was established by the State Lands Division near the Corps of Engineers’ Range BB-3 early in 1969, and was measured daily for about 6 months by Stinson State Park personnel at 16 points along the range. (Thompson, 1970.) 6. In the vicinity of the range (5) above, the State Lands Division established the position of mean high tide line for a distance of about 500 feet along the beach face on 11 occasions from October 1948 through December 1969. These data are available from State Lands Division (1970) in Sacramento. 7. Bottom topography within Bolinas Lagoon was obtained from soundings made in July and August 1939 by the San Francisco District, Corps of Engineers, (1939 and 1956). 8. Bottom topography within Bolinas Lagoon was obtained from aerial photography by R. M. Towill, Corp. for the Bolinas Harbor District, (Gilroy, 1970a), and by the USGS in 1967 from profiles of the bottom along 25 ranges. (Ritter, 1969.) 9. Soundings in the Bolinas Lagoon entrance channel were made in October 1956 by the San Francisco District, Corps of Engineers (1956). 10. Three cross sections at the throat of the Bolinas Lagoon inlet were obtained when the USGS measured the quantity of sediment moving in and out of the inlet, 22 June, 24-25 October 1967, and 16-17 May 1968. (Ritter, 1969.) 2. Wave Data. The most important factors in coastal sediment processes in the nearshore area are wave action and tidal currents. Wave data representative of the general area of Bolinas Bay have been compiled from visual observations, the hindcasting technique, and a recording wave meter. The nature and period of record of these various data follow: a. San Francisco Light Ship. These data were obtained by visual observation every 6 hours (0430, 1030, 1630, and 2230 PST) and transmitted to the U.S. Weather Bureau in San Francisco where the wave height, period, and direction were entered in code on the weather charts issued for each of these 6-hour periods. The weather charts for the 3-year period from 1 September 1949 through 31 August 1952 were procured, and the wave data summarized by wave roses. (Johnson, 1953.) These roses show the percent of time that various wave heights and periods occurred during the various months of the year averaged from the 3 years of record. Such data are relatively crude compared with the other data listed below. b. Hindcast for Deepwater Station (37.5°N, 123.0°W). Wave roses were prepared for a deepwater station by hindcasting from weather maps for the 3-year period 1936—1938. (Scripps Institution of Oceanography, 1947.) The 3-year period was considered to give a good representation of the average wave conditions, but did not necessarily include the most extreme conditions which could occur. Data on southern swell also were not included. The roses show the percent of time that waves of various heights occur during three periods throughout the year—summer, winter, and a transition period. c. Hindcast for Deepwater Station (37.6°N, 123.5°W). Deepwater wave statistics for 10 stations along the California, Oregon, and Washington coasts were compiled by hindcasting techniques using meteorological records and charts for the years 1956, 1957, and 1958. (National Marine Consultants, 1960a, 1961.) The statistics include wave height, wave direction, and wave period of both sea and swell, and are presented as monthly and annual averages in both tabular form and roses. Asin item b above, data on southern swell are not included. Station 3 for the California coast (National Marine Consultants, 1960a) located at Lat. 37.6°N and Long. 123.5°W provides wave data which are representative of conditions offshore from Bolinas Bay. d. Iindcast of Severe Storms. Wave statistics were compiled by hindeasting techniques for the 10 most severe storms for three selected stations off the Northern California coast during the period 1951-1960. (National Marine Consultants, 1960b.) Station 3 (37.6°N, 123.5°W) is representative of severe wave conditions offshore in deep water from the Golden Gate. For each storm the significant heights and periods and direction of waves are tabulated for four times each day for the duration of the storm. e. Bolinas Bay Wave Recorder. A pressure-tvpe wave recorder was installed in 18 feet of water in Bolinas Bay by the Bolinas Harbor District in February 1969. Except for a few days, when the recorder was inoperative due to power or other failures, continuous records were obtained from 20 February to 23 August 1969. Significant heights and dominant periods at the wave gage were compiled and plotted against time. (Gilroy, 1970a, App. No. 3.) No data were available on wave direction. J. Stinson Beach State Park and Bolinas, California. Surf observations at Stinson Beach by State Park personnel and at Bolinas by personnel of the Bolinas Harbor District were instituted in May 1968 following procedures prescribed by the Coastal Engineering Research Center (CERC). (Darling, 1968; Berg, 1968.) Visual observations (twice daily) were made and recorded on wave period, height, and direction; breaker type; wind speed and direction; littoral current speed and direction; berm height; and beach slope. A report on the observations at Bolinas and Stinson Beach State Park for the period Februarv—December 1968 has been published by CERC. (Szuwalski, 1970.) Computer readouts for the entire period of record are available upon request from CERC. 3. Wave Refraction. Wave data from the San Francisco Light Ship and the three hindcast summaries (items a, b, c, and d in the above section) refer to deepwater conditions. When waves move from deep water into shallow water, changes in the wave heights usually occur as a result of refraction and diffraction. The characteristics of the bottom topography, the wave period, and the direction in dee; water determine the pattern of the wave crests, and consequently the wave heights, in shallow water. Refraction diagrams prepared by the San Francisco District, Corps of Engineers (Table 1) show how the waves from deep water transform while approaching the central California coastline. Table 1. Corps of Engineers Refraction Diagrams for the Central California Coast Location Wave Wave Direction (sec) Point Reyes to Santa Cruz es ee 1:210,000 Golden Gate north to Fort Ross 1:210,000 1:210,000 not given 1:210,000 1:210,000 not given not given 1:210,000 not given 10 The refraction diagrams listed in Table 1 are on so small a scale that the orthogonals terminate at about the 10-fathom contour; hence, no information is given on the refraction of the waves as they move into the shallow water of Bolinas Bay. To provide such information, a few refraction diagrams at a large scale have been prepared for waves of the average period of 12 seconds approaching from the critical directions of west-northwest, west, and south-southwest. (Gilroy, 1970a, App. No. 3.) 4. Wave Power. In certain coastal sedimentation processes, such as the possible closure of tidal inlets, the wave power at the shoreline appears to be important. Wave data compiled by the hindcast technique for 10 deepwater stations along the California, Oregon, and Washington coasts (National Marine Consultants, 1960a, 1961) have been used in the preparation of a summary of annual wave power for these 10 Pacific Coast stations. (Johnson, Moore, and Orrett, 1971.) This summary also contains wave power data by months for Station 3 off the California coast at Lat. 37.6°N and Long. 123.5°W. The wave power, P, in deep water is given as follows: peel Tone where yH? L oO = II Energy per unit width of crest = H, = Deepwater wave height = Deepwater wave length = Wave period StS} ote | Unit weight of water or the power in ft-lbs per sec per unit width of crest is 2 Pa dH eu The total power for a month would equal the product of the average power per second for that month times the number of seconds in the month. Since the compilation of statistical data (National Marine Consultants, 1960a) gives the percentage of time that waves of various heights and period occur, the total power for each month has been computed for both sea and swell, and is discussed in Section III. 5. Longshore Currents. When waves break at an angle to the shore, a longshore current is induced, and is effective in moving water and sediment along the shore. Observations of the ll strength and direction of longshore currents at the Stinson Beach State Park and at Bolinas were started in May 1968, and continued for about 2 years at Stinson Beach and 1 year at Bolinas. The observations for 1968 have been published by CERC. (Szuwalski, 1970.) Printouts of the complete records are available upon request. 6. Littoral Transport. Littoral transport is defined as the movement of material in the littoral zone by the wave-generated littoral currents. In 1965, an 80-mile reach of the central California coast, extending from the mouth of the Russian River in the north to Half Moon Bay in the south (Fig. 1), was studied for the characteristics of sediment movement in the nearshore zone. From the results of many beach and offshore sediment samples and other information, several techniques were utilized in appraising the nature of sediment movement along this coastline. The following were studied: (a) the physical nature of the coastline from a consideration of the prevailing wave energy, (b) the distribution of light and heavy minerals and their sources, (c) the use as tracers of certain naturally radioactive minerals, and (d) the sedimentation experience at harbors where both natural and stabilized entrances exist. It was concluded from these studies that the transport of nearshore sediments in this region (which includes Bolinas Bay) is relatively small. (Johnson, 1965.) The only actual measurements of sediment movement in Bolinas Bay were a limited number of observations on littoral drift made by the USGS using fluorescent-dyed sand at three beach sites in the Bay. (Ritter, 1969.) Other data providing information on the general movement of sediment in the entire Bolinas Bay resulted from the use of heavy minerals as tracers. (Wilde, et al., 1969; Wilde and Yancey, 1970.) 7. Bottom Sediments. The mechanical and mineralogical characteristics of beach and offshore sediments in Bolinas Bay have been under investigation for several years by the University of California on a project sponsored by CERC. (Moore, 1965; Isselhardt, et al., 1968 and 1969; Wilde, et al., 1969.) 8. Tidal Relationships. The reference tide station for central California is the National Ocean Survey (NOS) (formerly USC&GS) gage located at The Presidio, San Francisco. Lower low water datum at this station is based on miscellaneous observations prior to 1907, and adopted as standard in March, 1907. Elevations of other tide planes referred to this datum are based on the 19 years of records, 1941-59. The USC&GS operated a tide gage for a short period at Bolinas (probably immediately inside the Lagoon entrance) and apparently used these data in calculating the difference in the time and height of tides at Bolinas Bay and Bolinas Lagoon with respect to The Presidio, San Francisco. The 1972 NOS Tide Tables for the west coast of North and South America give the tidal differences shown in Table 2. Additional statistical data on tidal planes at San Francisco, Bolinas Bay, and Bolinas Lagoon are presented in Table 3. 9. Surveys of Beaches and Bottom. As previously mentioned, several beach and bottom surveys were conducted over the last few years by various agencies to determine the hydrography in both Bolinas Bay and Bolinas Lagoon, and to evaluate seasonal changes of the shoreline in this area. Details of these surveys follow: 12 Table 2. Tidal Differences—Bolinas Bay and Bolinas Lagoon Differences Time (hrs—min) Height (ft) Mean (ft) | Diurnal (ft) High Water |Low Water | High Water |Low Water ragonarg Bolinas Bay —0.17 Bolinas Lagoon +0231 San Francisco (Golden Gate) — Daily predictions * A plus (+) sign indicates that the tide at the subordinate station is later than at the reference station, San Francisco, and the difference should be added, a minus (—) sign, that it is earlier and should be subtracted. + Ratio of height at subordinate station to the height at San Francisco. Table 3. Tidal Data Tidal Plane San Francisco |Bolinas Bay | Bolinas Lagoon (feet) Highest Tide, 24 Dec. 1940 d — Higher High Water ; 2 4.4 High Water Springs : : 4.1 Mean High Water : sl 3.8 High Water Neaps : ; 3.9 Mean Tide Level : : Desa) Sea Level Datum (1929)* 1.9 Low Water Neaps Ls : all Mean Low Water all ol! 0.8 Low Water Springs 5 ‘ 0.5 Mean Lower Low Water ‘ { 0.0 Lower Low Water Lowest Tide, 26 Dec. 1932 and 17 Dec. 1933 Tidal Range *The U.S. Geological Survey mean sea level is identical with the 1929 U.S. Coast and Geodetic Survey sea-level datum. 13 a. Corps of Engineers. Bottom surveys in,Bolinas Lagoon were made between 26 July, and 8 August 1939 and in October 1956. Five ranges along the bay side of Stinson Beach spit were surveyed in March and August, 1971. Depths and elevations in all of these surveys were referred to local MLLW. At the time of these surveys, MLLW was listed by the USC&GS as being 2.07 feet below the 1929 sea-level datum (SLD). On 6 May 1965, the USC&GS revised these values such that now MLLW in Bolinas Lagoon is listed as being 1.9 feet below the 1929 SLD. The five Corps of Engineer ranges were resurveyed (on the beach face only) by the State Lands Division, 3-4 March, and 3 April 1969. The Corps’ bench marks, previously established in their 1961 surveys, were used for the vertical control; mean lower low water was assumed as 2.07 feet below the 1929 USC&GS sea-level datum. b. Bolinas Harbor District. In 1968 and 1969, the Harbor District contracted with R. M. Towill Corp. of San Francisco to conduct the five bottom surveys offshore in Bolinas Bay as previously mentioned. Surveys of Bolinas Lagoon were also made by R. M. Towill Corp. from aerial photographs taken at low tide on 16 May 1968. All of the Oe surveys give soundings below the 1929 USC&GS sea-level datum. c. U.S. Geological Survey. In August and September 1967 profiles of the bottom of Bolinas Lagoon were surveyed along 26 referenced ranges to document the location and configuration of channels. Elevations and depths were referred to the 1929 USC&GS sea-level datum. d. State Lands Division. From 1948 to 1968, the State Lands Division determined the alinement of mean high tide for a distance of about 500 feet along the beach face on Stinson Beach Spit. Mean high tide was assumed to be 3.8 feet above the mean lower low water for Bolinas Lagoon (Table 3) or 1.9 feet above the 1929 sea-level datum. 10. Tidal Prism. O’Brien (1967) established a unique relationship between the minimum flow cross section of a tidal inlet and tidal prism (the volume of water that flows into and out of the lagoon during a tidal cycle). From the R. M. Towill bottom surveys of Bolinas Lagoon, the USGS (J. R. Ritter, 9 July 1971, private communication), prepared a contour map of the lagoon and calculated the volume of water in the lagoon at several tide stages as follows: Tide Stage Volume (MSL Datum) (feet) (million cu ft) From a plot of these data the tidal prism between MLW (+0.8 MLLW) and MHW (+3.8 MLLW) was determined to be 109 million cubic feet. 14 11. Tidal Currents. Data on currents resulting from tidal action within Bolinas Bay are relatively sparse. Known data follow: 1. Measurement of water and sediment flow through a section of the entrance to Bolinas Lagoon was made over a tidal day by the USGS on three occasions, 22 June, 24-25 October 1967, and 16-17 May 1968. (Ritter, 1969.) 2. A limited number of current measurements by the use of current drogues, dye, and bottle caps were made in Bolinas Bay and vicinity in connection with a sewerage study for Marin County. (Brown and Caldwell, 1967.) 12. Sediment Transport in Bolinas Lagoon Inlet. Suspended-sediment discharge in or near the inlet was measured during the tidal current measurements mentioned above. (Ritter, 1969 and 1972.) 13. The Ecosystem. Although not of primary importance in relation to the inlet to Bolinas Lagoon, an extensive series of studies of the ecosystem of the lagoon was completed by a team led by Joel Gustafson of Resources and Ecology Projects, Inc. Reports on this phase of the total investigation of Bolinas Lagoon are included in the report by Gilroy (1970a, App. No. 6). Ill. SUMMARY OF DATA RELEVANT TO THE INLET The investigations pertaining to various natural processes occurring in the Bolinas Bay- Bolinas Lagoon-system were briefly described in Section I. Data for those aspects of the system which specifically influence the dynamics of the Bolinas Lagoon inlet are summarized as follows: 1. Wave Data. The most reliable data on wave climate and severe storm conditions for the central California coast are those compiled by National Marine Consultants (19609a, 1960b) for Station 3 at Lat. 37.6°N, Long. 123.5°W. (See Figure 1.) Figure 2 presents the average annual sea and swell data for Station 3. These data are for deep water, and to project such information to the vicinity of the Bolinas Lagoon inlet requires the use of wave refraction diagrams for a large range of wave periods and directions. An illustration of wave refraction into Bolinas Bay is shown in Figure 3 for a 12-second wave from the west. As previously mentioned in Section II, some visual observations of wave conditions were made in 1968-69 at Stinson Beach State Park and at Bolinas. Also, a wave gage was operated offshore between the two beach stations. The locations of these observation sites are shown in Figure 4. It is of interest to note that the wave direction observed at the Bolinas station by a special sighting device showed that for the entire period of observation waves approached the Bolinas Lagoon inlet within a narrow sector between 10° and 20° east of south. (Gilroy, 1970a, App. No. 3.) Summaries of data on wave power and littoral currents derived from observed and hindcast wave data are presented below. 2. Wave Power. As mentioned in Section II, computations of wave power (both sea and swell) were made for Station 3 offshore from the Golden Gate. (Johnson et al., 1971.) A plot of the monthly wave power (H?T) for all directions of both sea and swell is shown in Figure 5. The power in swell is relatively small in this region during June, July, and August. 15 (QO96L ‘ROOST STURINSUOTD VUTIR], [PUOTRA)) “0}eH Uap[O JO JSOM “SoSOd [[OMS PUB BIS “ ainsi € NOlLViS YO4 3SOY¥ VW3S TIWANNY 39V¥3AV € NOllviS 4OJ 3SON 113MS IVANNY 39VY3AV +aG er \ 4esie zoe t +S N6LSE4 saTN6LSEt S S 3SS MSS 3ss MSS n6e2c¢ € I MSM +6iSi 16 26 € MNM ras. ied s ei + 1 MNM +R i625 € 1 319s . N (H‘29u243n390 %) WVH9O LSI Op of oe fo} MNN Os CI) MNN +6 ELS (@ ‘23u943n230 %) 3SOY N z - +GGi | 6 2G € 1 yt fl 16 BOLINAS LAGOON USC &GS } CHART NO. H-4975 DUXBURY POINT / S % % ‘ +| T=!2 SEC FROM WEST 122° 40' | Figure 3. Wave refraction diagram. Twelve-second period wave from west. (Gilroy, 1970a.) BOLINAS LAGOON BOLINAS ~ BOLINAS Mean high tide lines STATION 4 \i-. and beach profiles by State of California < 8 € 40 RT —— STINSON % \, BEACH & S x STATION RY zg ee BAY Figure 4. Location of bottom surveys, beach ranges, beach observation sites, and wave gage in Bolinas Bay. (Johnson, 1970.) 18 ¥ (HST) ft. lbs /month/ft SUM OF SEA AND SWELL Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Figure 5. Deepwater wave power (sea and swell) for various months at Station No. 3, California coast. (Johnson, et al., 1971.) 19 The power in sea, on the other hand, increases gradually from January to July, and then decreases during the remainder of the year. The sum of sea and swell also is shown in Figure 5. This latter curve shows that total wave power is least during July, August, and September. To transpose deepwater wave power shown in Figure 5 to nearshore points in Bolinas Bay requires the use of refraction and diffraction diagrams for a large range of wave periods and directions. Unfortunately such diagrams are not available. However, to obtain some measure of relative intensity of wave power in Bolinas Bay, the visual wave observations (at Bolinas and Stinson Beach State Park) and the data from the wave gage in the bay were used. Wave data for these three locations (Fig. 4) were available for the following periods: Bolinas, | May 1968 to 23 February 1969 Stinson Beach, 1 May 1968 to 30 November 1969 Bolinas Bay wave gage, 20 February 1969 to 23 August 1969 For each of these stations the wave height and period were tabulated for each day of record. The data from the Bolinas and Stinson Beach Stations were breaker heights (Szuwalski, 1970); data from the wave gage were the heights recorded offshore over the underwater pressure unit. Values of H* T were computed for each day for each location. To smooth the data and provide a visual comparison of the relative magnitude of wave power at the three localities, 5-day moving averages were computed, tabulated, and then plotted in Figure 6. The effect of wave exposure is seen by comparing the plots from Stinson Beach State Park and Bolinas. The Stinson Beach station is more exposed to the prevailing waves from the west-northwest sector than the Bolinas station which is near the Bolinas Lagoon inlet, and consequently receives protection from Duxbury Reef. (See Figure 3.) Unfortunately the Bolinas observation program was terminated before the installation of the Bolinas wave gage; therefore, a comparison of wave power at the gage can be made only with the Stinson Beach data. The wave gage is more protected from wave action by refraction effects than is Stinson Beach. A further comparison of relative magnitude of wave power is shown in Figure 7. In this figure the monthly wave power (sum of sea and swell) for the offshore station (Station 3) summarized in Figure 5 is plotted along with the monthly wave power as computed from the wave data observed at Bolinas and Stinson Beach. The figures show wave power is least at Bolinas, somewhat higher at Stinson Beach, and both are significantly less than the exposed deepwater station. 3. Longshore Currents. The strength and direction of longshore currents generated by waves breaking at an angle to the shoreline are necessary data in evaluating such shoreline processes as littoral transport and seasonal beach and bottom changes in Bolinas Bay. The only known measurements of longshore currents in Bolinas Bay were the surf observations made at Stinson Beach State Park and at Bolinas. Printout data for these stations were obtained from CERC. Plots of the observations on longshore currents (strength and 20 ¥ (HST) ft. lbs/month/ft STATION 3 WRIGHTS STINSON May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr 1968 -—_+— 1969 Figure 6. Wave power for Station No. 3 (California coast) compared with beach observations at Stinson Beach and Bolinas Bay. 21 ‘8K OABM SPUT[OY oy) pue ‘eg seuTTog ‘yoRog UOsUTS Jv SUOCTRAIOSqO WO. Jamod oARM Jo soseIoAe SULAOU Aep-OATY *L ainsi 6961 696 Saleem cco! 8961 AON 190 jdas Bny Aine aune Aow Jludy YosDW qa4 upe 29Q AON 420 tdas Bny Aine aunce Kow SeoeSiOiS SzO2SiOiS S2ZoOzsiOiS S2oesiOiS SecesiOl S oesiaiS szoesiois SeoesioiS s2ozsiois Szozcio1s S20esiOlS s20z2si0i1S SeoesiOiS S20esi0iS SzO2SiOiS_ Sz02si0i S MAA! TT vaya lnlulululaalalulatal mean TTT Tot Szozsiois Seozsiois Seoesiois 0 2609 andM SOu!|0 souljog " 49009 aA0M ' yodag uosUIIS. , : a. 8 eS 4 it : M \ \ a % H S . H H =< A AK ' ray 5 i < | iY = On z= | : u < \ { 2 eee LJ @ 134 “ 1 Sa t 7 | 0b , ra | = 1 a a" Fa I ir 1 00s _ an = i 3 i i 1H 8 [ | rel ] | 009 & rr ron direction) and wave period from these printouts are shown in Figure 8. The data for the two stations show that there are extended periods when the longshore current prevailed in one direction. For example, from February to June 1969, the longshore current at Stinson Beach was generally in a southeast direction with a reversal occurring on only about 15 days during the 5 months of record. (Johnson, 1970.) 4. Sedimentation Processes—Bolinas Bay. Sedimentation processes in Bolinas Bay cause both short- and long-term effects. The long-term effects are the slow natural changes which may be detected only by a close comparison of bottom and beach surveys which have been repeated over the years. The only sources of reliable information on bottom changes are the USC&GS hydrographic surveys which have been repeated at several intervals since 1854. A comparison of these surveys was made, and it was concluded that the Stinson Beach spit has been stable in geometric configuration since the first survey in 1854; that is, the shoreline of Bolinas Bay is in dynamic equilibrium. (Gilroy, 1970a, App. No. 3.) a. Bottom Changes. To obtain a measure of the seasonal bottom changes in the area offshore from the inlet, each of the five surveys made between 17 May 1968 and 16 May 1969 for the Bolinas Harbor District was compared with the next following survey. The depth of scour or fill was noted on an overlay. (See Figure 4 for general area covered by the bottom surveys.) These overlays were then contoured to give areas and depth of scour and fill occurring between the two dates. Thus, four comparison maps resulted, and a comparison map for 1 year from the initial survey on 17 May 1968 to the final survey on 16 May 1969. (Gilroy, 1970a, App. No. 3; Johnson, 1970.) An example of these maps is presented in Figure 9 which shows a comparison between the survey of 21 August 1968 and that of 19 December 1968. An area of scour occurred near the entrance of Bolinas Lagoon, but a general fill occurred over the remainder of the area surveyed. The largest fill occurred near the surf zone—probably such material was removed from the beach face and deposited immediately offshore by early winter storms. As a result of this general fill the position of the 30-foot depth contour in December was further offshore than in August. That sand may be shifted laterally within Bolinas Bay is shown in Figure 10 which compares positions of several depth contours as they existed on 17 May 1968 and on 16 May 1969. This figure shows that the area opposite the entrance to Bolinas Lagoon in May 1969 had been generally filled compared with May 1968; that is, over most of the area the May 1969 contours are seaward of the 1968 contours. On the other hand, at the east side of Figure 10, a region of scour has occurred; that is, the 1969 contours are generally shoreward of the 1968 jositions. This indicates that, between the 1968 and 1969 surveys, sand appears to have been shifted northward from Stinson Beach into the north end of Bolinas Bay. Wave conditions and tidal currents in the following year could possibly be such that the material would be shifted back in an east and southerly direction. In the comparison maps discussed above, the actual depths of scour and fill are subject to some sounding error, but the areas of scour and fill show no randomness and are consistent with seasonal changes generally observed elsewhere. 23 ‘eIudlojley) ‘sSeulpog pue YAeq 97e1S ane 6961: AutAy3s ABVONVE 838A3930 i CREEL ELL BIG WOSUTZS 380190 6 CECLEICER (0261 ‘Uosuyol) 69-896 S}UALIND IOYssuoy pur portad are Ay 8961 asnony 2" O01N2¢ ~ SIN3YYND JYOHSONOT * AL19073A -—- MoS AN ° > 896! AUVnNVE ¥38A3930 ¥38NJAON 9380130 CEL EPCELS asnony = MS MOlLI2uIO 8 andy “001u3d Boy “ALIDOVIA 1SIMALUONS— —oISVIMINOS mirigy wONLIJBI0 Y od SHORELINE OFFSHORE BAR SURF ZONE SURF ZONE eel c AUG 21,1968 —— 6 30 FT DEPTH # ae CONTOURS ae DEC 19, 1968 — Figure 9. Areas of scour and fill between 2] August 1968 and 19 December 1968. Values are in feet. (Johnson, 1970.) SHORELINE = FILL@—t—> ScouR MAY i7, 1966 ———— MAY 16,1969 Figure 10. Comparison of Bolinas Bay bottom contour mays of 17 May 1968 and 16 May 1969. Contours in feet. (Johnson, 1970.) Other data that provide information on the general movement of sediment in the entire Bolinas Bay are presented by Wilde and Yancey (1970) who utilized heavy minerals as tracers. Other supplementary data on sediment movement in Bolinas Bay resulted from sand tracing studies along the beach face by the USGS during investigations of sedimentation and hydrology in Bolinas Lagoon. (Gilroy, 1970a, App. No. 5.) This study used the placement of fluorescent-dyed sand on the beach at both the town of Bolinas (Brighton Avenue) and the Stinson Beach State Park with periodic detection of the direction of movement away from the source by use of an ultraviolet lamp. Sand, at both localities, was placed on 23-24 July 1968, and then periodically sampled until late October 1968 when the dved material either was completely scattered and buried or the dye strength had been greatly reduced. The results of these limited and qualitative tests by the USGS showed that at Bolinas the movement of sand was always eastward toward the entrance of Bolinas Lagoon, but no material ever crossed the lagoon entrance to the Stinson spit. Although the surf observations summarized by CERC showed a general westerly longshore current in this same locality during the period of the sand tracing studies (Fig. 8), it is possible that tidal currents into Bolinas Lagoon rather than wave-generated longshore currents moved sand generally eastward along the beach. In the Stinson Beach State Park studies, the dyed sand moved in both the southeasterly and northwesterly directions; some material was detected about 1.5 miles northwesterly up the beach 2 months after initial placement. This might be expected upon examination of Figure 8 which shows that a northwesterly longshore current prevailed over most of the period, (August and September), following the start of the tracer tests. b. Beach Changes. Beaches exposed to wave action undergo profile changes throughout the year, because of seasonal changes in wave characteristics. One of the most important factors in determining the character of a beach profile is the ratio of wave height to wave length—defined as wave steepness. During extended periods of low wave steepness, low berms usually are built beyond the foreshore with very steep profiles on the beach face, and bars immediately offshore tend to disappear or become discontinuous. During periods of high wave steepness (storm or winter conditions) the beach face becomes less steep and the offshore bars become more pronounced. On the beaches along Bolinas Bay, the seasonal changes in characteristics are less well defined than the changes in the offshore area. This lack of definition is primarily in the surf zone, and is the result of the difficulties and hazards of making accurate bottom surveys in the surf zone—especially during winter storms. The hydrographic surveys used in preparing the comparison maps (Fig. 9) were made no closer to shore than about the 8-foot depth contour. The data on seasonal beach changes are therefore confined to the beach profiles made by; (a) Trask (1959), and Trask and Snow (1961), and (b) the Corps of Engineers (1965) and repeat surveys of these ranges by the California State Lands Division in 1969. The location of the Corps’ ranges is shown in Figure 4. Surveys by the State Lands Division to determine the position of the mean high tide lines over a limited length of the Stinson spit for the period 1948 to 1970 are important in evaluating beach changes in Bolinas Bay. To provide an accurate measure of the seasonal fluctuations of the width of the beach at Stinson spit, the data on the position of the mean high tide line, as determined by the State Lands Division and other sources on 27 occasions from 1948 to 1970, are of value. To obtain information on the position of the mean high tide line, the distance from a base line to the high tide line was measured and plotted as shown in Figure 1] for the appropriate day of the month. (Johnson, 1971.) There is an obvious cyclic pattern of position of the high tide line with the seasons, but no precise relationship exists because of the variation of intensity of wave attack that undoubtedly occurred from year to year. An upper and lower envelope has been drawn in Figure 11 to enclose the plotted points. This plot shows that the position of the mean high tide lines is more variable from year to year during the spring months than during late summer and fall. The distance between envelopes during the spring may amount to as much as 50 feet, and the beach at the mean high tide line is about 150 feet wider in summer than in winter. The surveys of the five Corps of Engincers ranges showed an average difference in width of about 100 feet between winter and summer conditions of the mean high tide level. (Corps of Engineers, 1965.) 27 30C; { i ay : | 20 | H | ae ; | UPPER ENVELOPE, oe yak k 250 st ten mafee pt 7--- 4a /96: 200;— ; t- zi fama a) eel SLOWER ENVELOPE| | ane voller ms Jon Feb Mor Apr May June July Aug Sept Oct Nov Dec Distance of mean high-tide line from base line (ft) Month Figure 11. Seasonal variation of the position of the mean high tide line, Stinson Beach spit, 1948—1970. (Johnson, 1971.) Data which give more detail on the day-to-day changes in a profile on the Stinson Beach spit are those of Thompson (1970) which are plotted in Figure 12. The plots resulted from a field study conducted from 4 January through 2 May 1969 on a profile near the Corps of Engineer’s Range 3. (See Figure 4.) This profile was measured daily; the waves incident upon the profile were obtained from the Bolinas Harbor District wave gage. The daily position of the mean low water line, mean tide line, and mean high water line are indicated along with other elevations with respect to the 1929 sea level datum. The wide variation in the position of those lines (with time) in the zone of wave action is strikingly evident. 5. Inlet Characteristics. At most lagoon inlets, two opposing forces control the location and size of the opening. These forces are the ebb currents and the wave forces. The ebb currents provide a flushing action of the entrance and move sand offshore; wave action moves sand shoreward to fill the entrance. Often, the strength of the wave forces exceed those of the ebb currents, and the inlet remains completely closed (except possibly in times of flood, if appreciable stream flow enters a lagoon from a watershed). At bays or lagoons where wave refraction varies the wave height along the barrier beach between the lagoon and the ocean, the tidal inlet will be located where the forces of the ebb currents and the wave forces are approximately in balance. This is the condition at Bolinas Lagoon where charts and photographs show the entrance historically to be always adjacent to the Bolinas headland where refraction effects (Fig. 3) cause the least wave height of any location along the Stinson Beach spit. 28 OFF SHORE te 300 25 z SY INS & fs 20 y yk <2 Oe a0 a 8 ” 2 ¥ zg Ss N u z\ S&S & S z “ °° g = sx us 7 xn w~ S zt y O.« s? y Oo ny & St Soh 8 N 28 N x § = Gos gy Se t7) 3" a3 © & an 7 N S 4) N S84 NY g My 5 || 8 8 = a Ned 8 $2 = N 1 A A aes pai : Fes a Ss OF SE 7S YX OH RIM HIT 1 MLR WIIMBMLABAMIH | ZI IF CTA WH RAM See MPR WINS wMLUBW/ 234 S5E7TABIWN vanuany Se ES o | u 3 a sf = Ss a Ls 1” & N ——— be = — 10 2 res Ls SSS == x = al, | ~ 2 (SM) 15 17 18 180 2122123 £4125 Ba?) 289 90 31) 2154 516 7 A9 WN iL MG Mit We 19 202) exes ev 2s Beare 2950 2 s = fo 8 mance APRIL mar u net ine S WATE DATA WATE DATA FROM PRESSURE SENSOR LOCATED 1M A MEAN DEPTH OF 18 FT DIRECTLY SEARAAD OF BEACM PROFILE RATE MEASUREMENT SYSTEM LOANED BY CORPS OF EMSIMEERS TO BOLINAS HARBOR DISTRICT 4 UPPER GRAPH SMOMS SIGMIF/CANT WAVE ME/GNT . RELATIVE JO THE STILL WATER LEVEL So ‘ LONER GRAPH SWONS THE FAVE PERIOD OBTAINED ; Ron WAVE GROUPS = = eS = : ° TIDE DATA IN TOE DATA FROM CHGS TIBE TABLES (/Pa9) FOR BOLiMAS — KS = aN SS SS N is BAY [STATION NO c7/) TIDE NEIENTS ARE PREDICTED SS WS ~ aided aEtA > ll 31 Figure 13. Aerial vertical photo of Bolinas Lagoon inlet on 1 April 1945. High tide stage is 3.9 feet MLLW. (Hydraulic Laboratory photograjin, University of California.) 32 Figure 14. Aerial vertical photo of Bolinas Lagoon inlet on 31 August 1948; probably taken at high tide. (Hydraulic Laboratory photograph, University of California.) 33 Figure 15. Acrial vertical photo of Bolinas Lagoon inlet on 25 September 1959. Flood tide stage is 3.8 feet MLLW. (Courtesy of N. T. Gilroy.) Figure 16. Acrial vertical photo of Bolinas Lagoon inlet on 10 November 1959. Low tide stage is 1.2 feet MLLW. (Courtesy of N. T. Gilroy.) 39 Figure 17. Aerial vertical photo of Bolinas Lagoon inlet on 24 May 1961; probably taken at low tide. (Photograph, California Department of Fish and Game.) 36 Figure 18. Aerial vertical photo of Bolinas Lagoon inlet on 19 June 1962; probably taken near low tide. (Courtesy of N. T. Gilroy.) 37 Figure 19. Aerial vertical photo of Bolinas Lagoon inlet on 27 May 1968; probably taken at high tide. (Photograph, R. M. Towill, Corporation.) 38 2 Figure 20. Aerial vertical photo of Bolinas Lagoon inlet on 9 November 1969. Ebb tide stage is 4.4 feet MLLW. (Courtesy of Marin County Planning Department.) 39 C1261 ‘200TY “Y “f) ‘syueuLoImseour [eply AoAIng [eoLsoJoay “S"/) WOIy Jo[UT UOOSET] seUTOg ye sUOT}OeS Jeo, “TZ ans 499} © JINVLSIO OO0¢ OS2 00¢ OS| 001! OL GIP 2961 ‘22 3JNNL —~ 7 13A31 VaS NVAW Ye 4SVYS yaa HOIH NaN NOILVA313 4aa4 40 contribute to its filling. A large part of the stream-born sediments finer than sand entering the lagoon also probably remains in the lagoon. The USGS studies show that the lagoon’s circulatory pattern is nearly inoperative as a self-flushing, self-maintaining, dynamic system. (Gilroy, 1970b.) Although the Marin County Parks and Recreation Department (1971) recognizes that there are areas in Bolinas Lagoon of pollution, poor circulation, and increased sedimentation, no recommendation has been made to correct a situation which can only lead to an increase in the sedimentation rate in the lagoon and consequent deterioration of the system. To correct this undesirable condition, it would appear to be ideal to apply the principal proposed by O’Brien (1971) to improve the interior channels as follows: “Dredging shoals between LW and HW in the shallow upper reaches of a lagoon or estuary will not only aid in the maintenance of navigation channels, but wul also improve the water exchange and flushing of the lagoon or estuary.” Fine sediments resulting from cliff erosion on the outer coast enter the lagoon on the flood tide. Some of these sediments are carried well into the lagoon, and contribute to its silting. As emphasized by Ritter (1969) and Gilroy (1970b), nature, with some assistance from man’s operation on the watershed, will transform Bolinas Lagoon by sedimentation into a muddy meadow. As mentioned in the General Comments in Section II, a tidal lagoon inlet may be closed completely by the forces of wave action long before the tidal prism is reduced to zero by sedimentation processes in the lagoon. J. R. Ritter, (19 Sept. 1972, private communication), estimates that Bolinas Lagoon will become filled to highest high water in about 500 years, if the present rate of filling (16 acre-feet per year) continues. This rate is based on the rate of deposition over the 29-year period between the bottom surveys by the Corps of Engineers, 1939 and the Bolinas Harbor District, 1968. C. Wahrhaftig (Conservation Foundation, 1971) estimates that the lagoon will be converted to dry land in 500 to 2,000 years if the past average rate of sedimentation were to continue. Actually, the lagoon entrance will probably close completely long before the lagoon is filled with sediment to the highest high water level. The time to closure, however, cannot be estimated because the closure criterion (the ratio of wave power to tidal power) for natural lagoons has not been established. Of interest, however, are the following lagoons along the northern California coast which appear to be always closed. Lagoon Surface Area (ft?) Lake Earl 10 X 107 Freshwater Lagoon 1 X 107 Stone Lagoon 2.6 X 107 Big Lagoon 6.8 X 107 Abbotts Lagoon 0.9 X 107 4] All of these lagoons are fully exposed to’the severe prevailing W to NW waves; whereas, Bolinas Lagoon (with a high-water surface of 4.6 X 107 ft?) is well protected by refraction effects from such wave exposure. Since the surface area of the lagoon is a measure of the potential tidal prism, it appears that Bolinas Lagoon inlet would be completely closed if it were subjected to the same wave exposure as the above listed lagoons. IV. CONCLUSIONS AND RECOMMENDATIONS The Bolinas Bay- Bolinas Lagoon-system is a natural laboratory—unique because perhaps more basic data cover almost every aspect of hydrography, wave action, tidal hydraulics, sediment transport, and the ecosystem than for any other lagoon. There are problems, however, in which further studies are highly desirable to provide knowledge on the natural dynamics of a lagoon system which has been undisturbed by man except for some logging operations in the 1870’s. From a consideration of the limited flushing action by tidal currents and the rate of sedimentation in Bolinas Lagoon it appears that the inlet will close completely long before the lagoon fills by sedimentation from the watershed, thus converting the lagoon from a saltwater to a freshwater environment. Those additional studies which are desirable and which would in no way influence the present environment of the Bay-Lagoon system or be unsightly in their operation, but which would be applicable to a better understanding of the natural processes occuring in tidal lagoons in general, follow: 1. Install tide gages in the ocean and in the lagoon to obtain data on such tidal hydraulic phenomena as ratio of tidal range in the ocean and lagoon, tidal lag, superelevation, channel friction, and wave setup. 2. Periodically survey the bottom of the inlet channel to document seasonal changes of the inlet resulting from variations in tide and wave action during the year. 3. Operate a wave gage offshore from the lagoon inlet to obtain a record of wave height and period. Supplement the wave gage observations with daily estimates of wave direction. 4. In view of the ecologically depleted condition of parts of the lagoon (pollution, poor circulation, and high sedimentation rates), it appears desirable to investigate further the simple means of correcting this undesirable situation by increasing the tidal prism in the upper reaches of the lagoon. An increase in tidal prism and reduction in sedimentation rates will also delay the time when complete closure of the inlet will occur and convert the lagoon from a salt- to a fresh-water body of water. 42 LITERATURE CITED BECK, J.R., “Use of Time-Lapse Photography Equipment for Hydraulic Studies,” Open-File Report, U.S. Geological Survey, Menlo Park, Calif., Sept. 1971. BERG, D. W., “Systematic Collection of Beach Data,” Proceedings of the 11th Coastal Engineering Conference, ASCE, Vol. 1, Sept. 1968, pp. 273—297. BROWN, E.I., “‘Inlets on Sandy Coasts,” Proceedings of the American Society of Civil Engineers, Vol. 54, 1928, pp. 505—553. BROWN, and CALDWELL, “An Interim Report on the Bolinas Watershed, Marin County Sewerage Study,” San Francisco, Calif., Mar. 1967. BRUNN, P., and GERRITSEN, F., Stability of Coastal Inlets, North-Holland Publishing Co., Amsterdam, 1960. CALIFORNIA STATE LANDS DIVISION, “Beach and High Tide Line Surveys on Stinson Beach Spit,” Unpublished report, State Lands Division of the State Lands Commission, Sacramento, Calif., 1970. CONSERVATION FOUNDATION, “‘Bolinas Lagoon,” (Appendix E, by Clyde Wahrhaftig), Washington, D.C., Feb. 1971. DARLING, J. M., “Surf Observations Along the United States Coasts,” Journal of the Waterways and Harbors Division, ASCE, Vol. 94, No. 1, Feb. 1968, pp.11-12. FRAUTSCHY, J. D., and INMAN, D. L., ‘Review of the Effects of the Mission Bay Jetties Upon San Migration,” Unpublished report, Institute of Marine Resources, Scripps Institute of Oceanography, La Jolla, Calif., 1954. GILROY, N.T., ‘“Bolinas Lagoon: Its System of Environmental Dynamics and Recommendations for Its Future Preservation and Utilization,” prepared for the Advisory Commission on Navigation and Ocean Development, State of California, the Board of Harbor Commissioners of the Bolinas Harbor District, and the County of Marin, 1970a. GILROY, N.T., “Environmental Planning of a Bay and Coastal Lagoon System,” Proceedings of the 12th Coastal Engineering Conference, ASCE, Vol. I, Sept. 1970b, pp. 1761—1766. 43 INMAN, D. L., and FRAUTSCHY, J. D., ‘Littoral Processes and thie Development of Shorelines,” Coastal Engineering, Santa Barbara Specialty Conference, ASCE, Oct. 1965, pp. 911-536. ISSELHARDT, C., OSUCH,L., and WILDE,P., “Recent Sediments of Bolinas Bay, California, Part A, Introduction and Grain Size Analysis,” Report No. HEL 2-19, University of California, Hydraulic Engineering Laboratory, Berkeley, Calif., Nov. 1968. ISSELHARDT, C., etal., ‘Recent Sediments of Bolinas Bay, California, Part B, Mineralogical Data,” Report No. HEL 2-22, University of California, Hydraulic Engineering Laboratory, Berkeley, Calif., Apr. 1969. JOHNSON, J. W., “Summary of Wave Data for San Francisco Bay and Vicinity,” University of California, Institute of Engineering Research, Berkeley, Calif., Report Series 3, Issue No. 349, Feb. 1953. JOHNSON, J. W., “Seasonal Bottom Changes, Bolinas Bay, California,” Proceedings of the 12th Coastal Engineering Conference, ASCE, Vol. Il, Sept. 1970, pp. 1383-1396. JOHNSON, J. W., ‘“‘Nearshore Sediment Movement—Central California Coast,’ Coastal Engineering, Santa Barbara Specialty Conference, ASCE, Oct. 1965, pp. 537-559. JOHNSON, J. W., “‘The Significance of Seasonal Beach Changes in Tidal Boundaries,” Shore and Beach, Vol. 39, No. 1, Apr. 1971, pp- 26-31. JOHNSON, J. W., MOORE, J. T., and ORRETT, E. B., “Summary of Annual Wave Power for Ten Deepwater Stations Along the California, Oregon, and Washington Coasts,” Report No. HEL 24-9, University of California, Hydraulic Engineering Laboratory, Berkeley, Calif., Oct. 1971. MARIN COUNTY PARKS AND RECREATION DEPARTMENT, “Preliminary Bolinas Lagoon Plan,” June 1971. MOORE, D.B., “Recent Coastal Sediments, Double Point to Point San Pedro, California,” Report No. HEL 2-14, University of California, Hydraulic Engineering Laboratory, Berkeley, Calif., June 1965. NATIONAL MARINE CONSULTANTS, “Wave Statistics for Seven Deepwater Stations Along the California Coast,” Santa Barbara, Calif., prepared for the U.S. Army, Corps of Engineers Districts, Los Angeles and San Francisco, Dec. 1960a. 44, NATIONAL MARINE CONSULTANTS, ‘Wave Statistics for Ten Most Severe Storms Affecting Three Selected Stations of Northern California During the Period 1951—1960,” Santa Barbara, Calif., prepared for the U.S. Army, Corps of Engineers, San Francisco District, Dec. 1960b. NATIONAL MARINE CONSULTANTS, “Wave Statistics for Three Deepwater Stations Along the Oregon-Washington Coasts,” Santa Barbara, Calif., prepared for the U.S. Army, Corps of Engineer Districts, Seattle and Portland, May 1961. O’BRIEN, M. P., “Estuary Tidal Prisms Related to Entrance Area,” Civil Engineering, Vol. 1, No. 8, May 1931, pp. 738-739. O’BRIEN, M. P., “Equilibrium Flow Areas of Tidal Inlets on Sandy Coasts,” Proceedings of the 10th Coastal Engineering Conference, ASCE, Vol. II, Sept. 1967, pp. 676—686. (See Journal, Waterways and Harbors Division, ASCE, Vol.95, No. WWI, Feb. 1969, pp. 43—52. O'BRIEN, M.P., “Notes on Tidal Inlets on Sandy Shores,” Report No. HEL 24-5, University of California, Hydraulic Engineering Laboratory, Berkeley, Calif., May 1971. RITTER, J. R., ‘‘Preliminary Studies of Sedimentation and Hydrology in Bolinas Lagoon, Marin County, California, May 1967—June 1968,” Open-File Report, U.S. Geological Survey, Washington, D.C., Apr. 1969. RITTER, J. R., “Sediment Transport in a Tidal Inlet,” Proceedings of the 13th Coastal Engineering Conference, ASCE, Vol. Il, July 1972, pp. 823-842. SZUWALSKI, A., “Littoral Environment Observation Progarm in California, Preliminary Report,’ MP 2-70, U.S. Army, Corps of Engineers, Coastal Engineering Research Center, Washington, D.C., Feb.—Dec. 1968. SCRIPPS INSTITUTION OF OCEANOGRAPHY, “A Statistical Study of Wave Conditions at Five Open Sea Localities Along the California Coast,” Wave Report No. 68, University of California, La Jolla, Calif., July 1947. CALIFORNIA STATE LANDS DIVISION, “Beach and High Tide Line Surveys on Stinson Beach Spit,” Unpublished report, State Lands Division of the State Lands Commission, Sacramento, Calif., 1970. 4.5 THOMPSON, W. C., “The People of the State of California versus William Kent Estate Co., Superior Court of California in and for the County of Marin, No. 32824, Plaintiff’s Exhibit 95, June 1970.” TRASK, P. D., “Beaches Near San Francisco, California, 1956-57,” TM-110, U.S. Army, Corps of Engineers, Beach Erosion Board, Washington, D.C., Apr. 1959. TRASK, P. D., and SNOW, D. T., “Beaches Near San Francisco, 1957-1958,” University of California, Hydraulic Engineering Laboratory, Berkeley, Calif., Report Series 14, Issue 23, Oct. 1961, 90 pp. U.S. ARMY, CORPS OF ENGINEERS, “Bolinas Lagoon Surveys,” Unpublished report, San Francisco District, Corps of Engineers, San Francisco, Calif., 1939-1956. U.S. ARMY, CORPS OF ENGINEERS, “Cooperative Beach Erosion Study of Coast of Northern California, Point Delgado to Point Ano Nuevo,” San Francisco District, Corps of Engineers, San Francisco, Calif., June 1965. U.S. DEPARTMENT OF COMMERCE, NATIONAL OCEAN SURVEY, “West Coast of North and South America,” Tide Table, National Ocean Survey, National Oceanic and Atmospheric Administration, Rockville, Md., 1972. WIEGEL, R. L., Oceanographic Engineering, Prentice-Hall, Inc., Englewood Cliffs, N. J., 380 pp. WILDE, P., and YANCEY, T., “Sediment Distribution and Its Relations to Circulation Patterns in Bolinas Bay, California,” Proceedings of the 12th Coastal Engineering Conference, ASCE, Vol. Il, Sept. 1970, pp. 1397-1416. WILDE, P., ISSELHARDT,C., and OSUCH,L., “Recent Sediments of Bolinas Bay, California, Part C, Interpretation and Summary of Results,” Report No. HEL 2-23, University of California, Hydraulic Engineering Laboratory, Berkeley, Calif., Sept. 1969. 46 dupgcn* €29 dug cn* (II 9 I SetteS) *eTIFL “I = “*FTTeD SuooseyT seutjog *¢ ‘usfid TepTL °*Z ‘“FTTeQ ‘ucose] seurtog - s}eTUF [epTL “| *S}eTUT Tayo We pue ‘seutjTog 3® seTpnjs einjny 03 eptns e se peztTiewuns aie joeTuUT uoosey seut{[og uo ejep eyq Jo AQTTTGeTTeAe pue Seinjeu ‘oa01nos euL *peTtdwod useq sey ejep jo Junowe o31eT e YyOTYM ut ALOJeIOGeT yTeinjeu e st weqsks ucose]-Aeg seur[og oy, *eoueUajJUTeM pue usTsep Zoqiey UT PeATOAUT SAseUTSUe 03 JSelejUT Jee13 Jo vTe sjseood Apues uo S}eTUT TePpT} FO soTAsTreqzOeIeyD ATeJUSWTpes pue IT[NeIpAy oul *on-€7 ‘d :Aydea80tTqQTg “(SL-77-1adH *“At07e10qGe7 SuTiseutTsuq OT[TNeapAy *ARTSTSATUQ *eTUIOJTTeD fh/-¢ *ou teded snosu -PTTA0STW *1e}UeD YoIeesey BuTIseuTsuq [eqseog *s*n) “sn{TTT *d oy “7/6, *‘leqUeD YyOIPesey ZuTIssUT3Uyq Teqseop “*s*n S*eA SATOATEg “34 “eTUTOFTTeD ‘JeTUyT uoosey] seuttog *M ‘Lf ‘uosuyor dm, gcn* (II ¥ I Seftes) *eTITL “1 “FF TeD ‘uoosey seurptog *¢ ‘usfid TepTL °Z “FFTeD ‘ucosey] seutpTog - SI@TUT TePTL *L *sSJeTUT 19yIO0 We pue ‘seuftTog 3e SeTpnqys einjnj 0} eptn3 e se peztiemuns o1e JoeTUT uoo3ey] seut{Tog uo ejep syq Jo ARTTTqQeTTeAe pue ‘einjeu ‘so1inos eUL *peTtdwos useq sey ejep Fo Junowe a31eT e& YOTYM UT ATOReIOGET yTeanjeu e sft wajzshs uocose7]-Aeg seut[og oy] *aoueUa}UTeEW pue ustsep AOqiey UT PSATOAUT SLeveUTZUe 07 4SaeTezUT JeeI3 Jo oie sjseod Apues uo SJeTUT TepTt} JO soTASTrej,OeAeYD AAejUeUTpses pue IF [NeIpAy sy *on-€y “d :AydesrsotTqTg “(SL-7-1aH “AtojeI0qeT Sup~ieseuTZuq IT[NerpAy *AQTSTeATUN “eTUIOFTTCD §y/-¢ “ou teded snoou -PTTA0STW *19}UeD YOAPeSey BuylseuTsugq TeqseoD *Ss*n) “SNTTT ‘d gy *y/6L ‘19]UeD YOIeVSeYyY ZuTIvsUT3Ug Tey3seoD *s'n S*eA SATOATEgG *34q “eTUIOJTTeED SJeTUy uocosey] seut[og "mM °c Suosuyor dw} gcn° €79 dmygcn* (II 3 I Setteg) “eTITL *I “FFTeD ‘uocoze7 seutjtog “¢ ‘ustid [epty, *Z “Jr Te ‘uocosey seuttog = sjeTUT TePTL *f *sJaTUT reyj0 We pue ‘seuT—Tog je seTpnjs ernjnjz 09 eptn3 e se peztzewums ore eTUT uoozey SeuTTOg uo ejep oy Jo AITTTqeTTeae pue ‘aanjzeu ‘aoinos eyuL *PpeTTdwod useq sey ejep Jo Junowe a3zeT e YOTYM ut ATOReIOGET qTeainjeu e st we3sks uoosey-Aeg seuTTOg eyy, *eoUeUeJUTeU pue ustTsep Joqiey UT PeATOAUT STaeUTZUe 03 JSeTeqJUT JeaI8 Jo ere sqseoo Apues uo SJeTUT TePT} Fo soTAsTreqoeTeyD ATejUeUTpes pue OT[NeazpAy UL *Qh-cy °d :hydera80tTqTg “(SL-7Z-TaH *At03eI0qGe7 SuTiseuTzuq OT[NerpAy *ARTSTeATUQ *eTUIOFTTeD fy/-¢ *ou zeded snoou -PTTO0STH °19}UeD YyoIeesey SuTAseuT3ug [Te seoD *s*n) “SNTIT °d gr *y/6L *1e}UeD YOIeeSey BuTLeeUuTsUy Teaseop °s*n S°eA SAFOATOG °Jq “eTUTOFTTeED ‘SJeTuyT ucosey seuttog °M °¢ Suosuyor dm gcn* (II 8 I Seftes) *eTIFL *L “FETED fucose] seutjog °¢ ‘usTid [TeptL *Z ‘“JTeD ‘uoose] seut{og - sjeTUT TePTL °*1 *sqoTUT 19yj0 We pue ‘seutT—Tog 3e Satpnqjs einjnjy 03 eptTn3’ e se peztaewums ore JoeTUT uoozey seutT—Tog uo ejep ey3 Fo AATTTGeTTeae pue ‘aanqjeu. 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