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Home My WebLink AboutMINUTES - 05091995 - 2.4 TO: BOARD OF SUPERVISORS Contra Costa ( FROM: HARVEY E. BRAGDON County DIRECTOR OF COMMUNITY, DEVELOPMENT DATE: April 19, 1995 SUBJECT: ACCEPTANCE AND APPROVAL OF THE SAN RAMON CREEK GREENBELT AND PARKWAY STUDY SPECIFIC REQUEST(S) OR RECOMMENDATIONS) & BACKGROUND AND JUSTIFICATION RECOMMENDATIONS 1 . Acknowledge the efforts of County Service Area R-7A in working with the City of San Ramon and the Town of Danville to develop the San Ramon Creek Greenbelt and Parkway Study and in funding the County' s portion of this effort. 2 . Approve the use of Volume 2, Trails Plan and Volume 3, r Restoration Guidelines and Treatment as a basis for decision making for land development applications which occur adjacent to the creek or along trails proposed in -this document. 3 . Request the Community Development Department to review the County General Plan Trails Map to determine if it needs to be amended to be consistent with Volume 2 trails plan. 4 . Request the Flood Control District (Public Works) staff to report back to the Board of Supervisors from time to time on efforts to improve the habitat along San Ramon Creek in concert with the concepts found in Volume 3 . f 5. Encourage R-7A to further advise the Board of Supervisors and County staff on opportunities or programs they might wish to sponsor in furtherance of the study. 6. Request the Public Works crews doing maintena e along San Ramon Creek to utilize techniques which enha ce a ' e vegetation and discourage exotic species . CONTINUED ON ATTACHMENT: R% YES SIGNATURE RECOMMENDATION OF COUNTY ADMINISTRATOR RE TI011y BOARD COMMITTEE APPROVE OTHER SIGNATURE(S) : ACTION OF BOARD ON Mav 9, 1995 APPROVED AS RECOMMENDED g OTHER VOTE OF SUPERVISORS I HEREBY. CERTIFY THAT THIS IS A X UNANIMOUS (ABSENT NoRe TRUE AND CORRECT COPY OF AN AYES: NOES: ACTION TAKEN AND ENTERED.. ON THE ABSENT: ABSTAIN: MINUTES OF THE BOARD OF SUPERVISORS ON THE DATE SHOWN. Contact: Jim Cutler (510/646-2034) ATTESTED May 9. 1995 cc: Community Development Department (CDD) PHIL BATCHELOR, CLERK OF County Administrator' s Office BOARD OF SUPERVISORS Town of Danville D CM;XEPUTY OR City of San Ramon Public Works (Flood Control) B County Council County Service Area R-7A JC:db a:srstudy.bo Y)+ San Ramon Creek Greenbelt and Parkway Study April 19, 1995 Page Two 7 . Request the Public Works Department to also report back to the Board on the process and timing for doing adequate flood control studies to allow revegetation efforts to commence. FISCAL IMPACT There are minor costs associated with staff reports on this program. Implementation of the trail and revegetation proposals will need to be analyzed based on specific future proposals . This costs of flood control efforts will need to be determined based on future reports to the Board. BACKGROUND/JUSTIFICATION For administrataive convenience the Walnut Creek/San Ramon Creek basin was divided into three analysis areas . In 1992, County Service Area R7-A joined together with the Town of Danville and the City of San Ramon to pursue a San Ramon Creek Greeenbelt and Parkway Study. This creek drains north through the San Ramon Valley as a major tributary of Walnut Creek. In 1993, the City of Walnut Creek adopted a Creeks Restoration and Trails Master Plan which provided guidance along Walnut Creek through that city. Further north, the County, the cities of Concord, Pleasant Hill, Walnut Creek, the East Bay Regional Park District and the Central Contra Costa Sanitary District were working on the Walnut Creek Revegetation Study. That study was approved by the Board of Supervisors in 1993 . This planning effort along San Ramon Creek is the last link of this 20 mile long stream to have a detailed revegetation plan considered for it . The prime consultant firm of Keller, Mitchell, Caronna was hired to provide technical guidance on this study under the day-to-day direction of the City of San Ramon. A Task Force of San Ramon, Danville, East Bay Regional Park District, County R7-A and County staff was established to oversee the study efforts and to hear public testimony on the issues . A three volume study resulted from this effort . The goal of the study was to establish a concept of preservation and use for the creek system that will allow it to become an integral part of the image of the three communities . Fundamental to this conceptual approach is the realization that the creek system is an important historical and living component of the San Ramon Valley. The study sought to result in an open space system that will become a memorable and identifiable part of the urban fabric. A trail is an important component to the creek study; it provides a linkage to the county-wide and regional trail system that connects downtown schools and parks to open spaces . The report is intended to serve as a policy document that will be approved by all three communities . When a development is being considered along any part of the greenbelt, part of the conditions placed upon the development will be to preserve and enhance the natural environment of the creek and to provide for public trails as shown within the plan. In this regard Volume 2 and 3 will serve to help guide County staff and the Planning Agency on providing conditions of approval for private land developments and a policy context for public projects along San Ramon Creek. Volume 1 was an existing conditions report which described the San Ramon Creek and its environs from Walnut Creek' s southern boundary south through the City of 'San Ramon. This report is for background purposes only. There are two reports before the Board today which have policy ramifications . Volume 2 is a Trails Plan. It provides details on the trail system already shown in concept in the County General Plan. I San Ramon Creek Greenbelt and Parkway Study April 19, 1995 Page Three Volume 3, Restoration Guidelines and Treatment, provides a framework restoring and enhancing the creek. It focuses on the need to return to creek native vegetation. The report acknowledges that the plan concepts can only be fully implemented after adequate flood control studies are completed. The Flood Control District is a major partner in causing positive change along San Ramon Creek. They need to work with the Corp of Engineers to determine the process for upgrading the creek through specific projects and maintenance practices . They will need to report back to the Board from time to time on the efforts at implementation. County Service . R-7A needs to continue it' s efforts in follow-up to the study and to work with County staff on implementation. They should also report on process of doing adequate flood control studies to allow revegetation efforts to commence. The County General Plan already shows a trail along San Ramon Creek, however, the Community Development Department needs to review the General Plan trail maps to see if modification to the General plan is needed or if it is presently adequate to assist in trail implementation. These study reports were considered by the San Ramon Planning Commission and by the Town of Danville' s Planning Agency in 1994 . County Service R-7A Advisory Committee approved it on March 28, 1995 and it is now forwarded to the Board for final action. Y F77 t a S cr r a ti� w a �. - t "ham,�✓. �: .T'�;5 � a'r:� r., to� y...' { � 16`yX3't �, �C k �><u,, C, ,R R. Y 3 � �.,., �.�' r� .4 S c-°� `a..r- s`` hAcy�• � -n' o- 7-4 IWO Owl r r 71 .mfr tv`s r `•rF'; � �s.; � �` �ua t Y u d� `S,.'r y� j r „ti;'-s t;. TT' 1 � 1 1�l �1. SAN RAMON CREEK GREENBELT AND PARKWAY STUDY VOLUME I EXISTING CONDITIONS Design Team: KELLER MITCHELL CARONNA Prime Consultant and Landscape Architecture SYCAMORE ASSOCIATES Ecological Restoration PHILIP WILLIAMS & ASSOCIATES, LTD. Hydrology THE HABITAT RESTORATION GROUP Wildlife and Fisheries Biology June 1994 ACKNOWLEDGEMENTS - The development of a comprehensive master plan for restoration of the San Ramon �F creek and creation of the greenbelt study through the communities of San Ramon, Danville and Alamo could not have been completed without the participation of citizens, staff and agency cooperation. Special appreciation is shown for Jeff Eorio, the Parks and Community Services Director for San Ramon, as the designated project manager for the three communities. He has made the formidable task of orchestrating consultants and administration possible. We want to thank our contacts and their superiors in each of these organizations for their willingness to commit their resources to this study. Support for this project was initiated out of a previous study downstream in Walnut Creek. Pam Rom, a creek activist, has a passion to look at the bigger picture and the tenacity to hold onto the goal of an uninterrupted healthy greenbelt and creek for future generations, from the headwaters of the San Ramon Creek and culminating in the outfall to the Suisun Bay. We thank her for being visionary. San Ramon Creek Greenbelt and Parkway Study Task Force Members Pam Romo, Citizen, Walnut Creek ij. Jim Cutler, Contra Costa County Community Development Department �� Milt Kubicek, Contra Costa County Public Works Department Paul Niemuth, Citizen, Danville Beth Stone, East Bay Regional Park District Wanda Longnecker, Citizen, Alamo Karen McPherson, Alamo Parks and Recreation District R7-A Marsha Somers, Parks and Recreation Department, Town of Danville Jeff Eorio, Parks and Community Services Department, City of San Ramon Contra Costa County Board of Supervisors Tom Torlakson, Chair Gayle Bishop Mark Desauliner Jeff Smith Tom Powers, Chair Alamo Parks and Recreation District R-7A Citizen's Advisory Committee Karen McPherson, Chair Claudia Waldron Nancy Kaplan Frank LaScala John Osher Mary Praznik, Alternate Andrew Young, Staff East Bay Regional Park District Board of Directors Jocelyn Combs, President Ted Radke Douglas Siden Susan Smartt John O'Donnell Oliver Holmes Jean Siri Pat O'Brien, General Manager Town of Danville Town Council Don Ritchey, Mayor Mike Doyle Millie Greenberg _. Mike Shimansky Dick Waldo Town of Danville Parks and Recreation Commission Brian Blue, Chair Lynn Yaney Loucy DeAtley John Foley Regina Groman Sandy Myers John Asmus Marsha Somers, Director City of San Ramon City Council " Hermann Welm, Mayor Gregory L. Carr ` Mary Lou Oliver Patricia Boom Curtis Kinney of Ramon R City o Parks and Community Services Commission Ken Mintz, Chair Sue Newman JoLynn Mull Nick Ragusano 1 Paula Reily Carol Rowley H. Abram Wilson Matt Kummell Jeff Eorio, Director 1 TABLE OF CONTENTS Page I. Executive Summary 1 Creek History and Background IL Introduction 3 III. History of the Site 8 IV. Surrounding Land Uses 10 V. Hydrology 14 Regional Overview Historical Context Hydrology Hydraulics and Flood Hazard Existing Channel Conditions Hydraulic Constraints and Opportunities VI. Biotic Resources 23 Objectives Methods Exisiting Conditions Vegetation Resources Fisheries and Aquatic Resources Biotic Resources by Stream Sections VII. Opportunities and Constraints 41 Restoration Opportunities - Vegetation Restoration Opportunities - Wildlife Restoration Opportunities - Fisheries Restoration Constraints - Vegetation Restoration Constraints - Wildlife Restoration Constraints - Fisheries VIII. Appendix 50 LIST OF FIGURES Index to Aerial Photo Maps 13 LU1-8, Existing Land Use C1-8. Existing Bank Conditions V1-8. Existing Biotic Resources t \•F � .�t '� � k k�..r sm� t3` 4;i�'Ck. �"5 ♦x:. ..f ,a.`ti Tv —Al �,�r�tt k►f ,, r,. t V.. f e .t t ') � Y ,d. -ev' -+ � i"y o '� -{v;�,Ys• t p. ''..r+ '_ � - st-R'r ��, ,s � ". .� `� r '„�•'" ,y �� r �r x off,s.'� � .�.j t :«. �� a - r 'cs�i��-li t t ;�L � � C t� � ': ME�� fy`.;x n! ! �.` - 3 P� rS- •—'.•, r N"a CR�. x.� f"t x - "Ji'• _ � r•� 'R' .+•:i. _ �f ��i f �U �1h�3'::S� r �t y.�(r� # _ 5. * 1 sl�;-� �,�•sott2!S.*Tk'��- � 1.J ,"F'`r� r r 7- 11 _ ,� 'ti_"c� .•.y* -,,t<� fir,•. `� ^`r y.36 <<2 ''9- ..'t•"' ;-\yrRT 'I..+S,yY x��` �. "`" - ,'/x,P;�".r1(S,`"'ti, 'S.. i•, - J" Crt'"_-t4F .t '�{ t� s_t � ot '.f �,,•• , JvH t --g. rSds: fit K:n s'.�' 't`"' ,i� *' i �� s� �'+'�.(,p�-sa rfiS�+ ' .atyS � �, te .,,�-..rY K• � �S 4'� a� - yi "r-`cts� - �_,,., Lam'' '3 � -'C'�'.r�' tr'�2t�rt•+3 .Jl� ''"+` 7'J� JF ( "l, Y .,t• L d.\'�. r y; � � - ��r �� '�S- " ' ,* b i�.t y?�•vC ,:-r' ,�:-.y.,.� �m~t 4t1�. ,T y,, f. c. .c <:3'r"' �• � ( '3X'��'r .: the 7> i r- trs r z� "r'(,t s, t k{'` � t"" - r�•�'�r ,gyp• � �>��3"rf .. .a�ya) t •'t^� -_ . ! eft. �� l EXECUTIVE SUMMARY CREEK HISTORY AND BACKGROUND San Ramon Creek is a resource unique to flood control, wildlife, biology and privacy the San Ramon Valley. Much of the creek for adjacent residents. The team is has, however, undergone biological, responsible for the findings and physical and hydrological changes that are summarizations included in the body of the j, primarily the results of human report. interference. Restoration and enhancement of the entire creek is intended to increase Concurrent with defining a program for the habitat value and re-create a continuous creek restoration, the consultant team wildlife corridor. In the process of studied and analyzed the creek's entire ten protecting the creek from further decay, mile stretch for potential additional measures are recommended that will recreational opportunities. Those enhance the riparian environment, repair opportunities would be developed in only bank stability, and provide public access publicly held lands. A number and awareness of the importance of the of pilot projects were initially considered; creek as a community resource. the list was subsequently narrowed down to four that provided some sense of THE STUDY historical context. The four proposed projects then became the subject of a The San Ramon Greenbelt and Parkway detailed design and analysis. Study was undertaken for the purpose of uncovering, evaluating and recommending This study identifies a preferred trail alternatives for San Ramon Creek wildlife location and alternative trail options. When enhancement, trail alternatives and bank land becomes available, construction can occur; however due to the broad ownership stability issues. involved, as well as the large scale of the In 1991, the San Ramon Creek Task Force project, considerable time will be required (consisting of staff and citizens from the to complete the trail system. Budgetary City of San Ramon, East Bay Regional considerations were not part of the scope Park District, Town of Danville and of this report. Contra Costa Services Area R-7a) selected A major goal of the San Ramon Greenbelt a team of consultants consisting of and Parkway Study is to link local and landscape architects, biologists, regional trails into a regional network. hydrologists, wildlife specialists, and Such a network helps reduce automobile vegetation restorationists whose charge was tusage and greatly broadens the recreational o develop a Greenbelt Master Plan for San experience. Ramon Creek. This team surveyed existing ' conditions of the creek and its environs. They analyzed issues relating to geology, 1 2 „L 1,;,�.r%h'. 4� ,r^CK ? [,-.,}r,�=� � .r � ti 7 ��ti �� e �+ct �•; •rag. �'t�. . r � +c timet•,' ^7 r"X . �\j- to '” � �; F ,M1�"�t -'• �y� i � ! � r.�- ..y,� �rt .e� _ .��*�if 1i.. ��' �•,� -d,.�, �, � ,r:;� ��:��r r�u``F ��i+.� 14 h.} :i; .+t?, {x�4-. � Yxt w a.�' M1� ` t � ��aft! I ^fi `v 1 �r 7! k,�33` .s �� ,,rx._ .•4 ,�_b� �`' '��j`„4 r },S' �h<• ;.: k . 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W Y. 7��.`��'A'.'R7�F�? ^..t.,.�' '"'a�y�� S' 2��"'�..- � I' J [ s � �at }4..� N"c'�:" r �h `y��• �'o?, `� t �'a S Y17 �$�-�� •.S�i'�'"`j.�C ,�' "� 5 1 _� r. ,; M..' �. ..-F/ s� r '. .� yyt�1�Y_Y"`�q. 1 'r"�l ? -�C �t -?7.�i! .lLe � L f YJ,.. fh�. lt`s-% �� s � .. f•y. 1y13: .F,?��' y� a.a �,YS-- ...,5 � -?r: < v�t, ,^'si'•rr.. .t � 4-., �y, ! � f '�r ti .�, ,,,Q��t ��,dr,:mY r ..5,rr� t..7 � �, s�x 'P` 'k„:. :tet '+'S.'t?�vr• .c .�c �- � � � �,4 atr � � S_•��F4 _�.c• �.°�x� Frr � „ty-�G.�v r •�F;v_,Sv... INTRODUCTION Preserving our natural waterways, and the San Francisco Bay; as a reintegrating them back into our riparian/woodland habitat for one of the communities, is a growing passion for state's most valuable-i.e., abundant and Americans. These streams, creeks, and diverse-wildlife and plant communities; as rivers link our open spaces and encourage a wildlife migration corridor that scientists an increasingly urbanized population to say is one of our best hedges against enjoy the outdoors. When we preserve or species extinction; and as a source of sheer restore our waterways, we also reestablish physical beauty. once contiguous wildlife passages, linking fragmented habitats and allowing complex But extensive residential, commercial, and communities of flora and fauna to industrial development over the last several reestablish themselves. decades has narrowed the channel of the San Ramon Creek, steepened its banks, and removed it from its central role in the cities and towns through which it runs. Without action, increasing levels of `{ adverse impacts to the Creek and its resources seem inevitable. There is a growing perception in the community of an urgent need to better manage this valuable resource. Accordingly, the San Ramon Creek Greenbelt and Parkway Study was initiated as a collaborative effort between involved local government entities: City of San i Despite this renewed enthusiasm, the state Ramon, Town of Danville, East Bay ■ of our national waterways has never been Regional Park District, and Contra Costa worse. Residential and commercial County Services Area R-7A(Alamo). On development has severely reduced the October 3, 1991, a multidisciplinary ability of our waterways to support life. consultant team was hired to prepare a Fully one-third of the nation's fresh-water study as a first step in restoring San fish species are suffering serious Ramon Creek. That team consists of population decline, and half of those are in Keller Mitchell Caronna, Landscape immediate danger of becoming extinct. In Architects; Sycamore Associates, California, only six percent of our original Vegetation Restorationists; Philip Williams riparian, or creekside, habitats remain. Associates, Hydrologists; and The Habitat Restorationist Group, Wildlife Biologists. In the San Ramon Valley, the San Ramon Creek has historically played an important A Task Force Committee was organized to role as a source of drinking water and review the planning process and ensure irrigation for the Valley's agricultural that the goals of all individuals and industry; as a filter for water running into agencies involved in the creation, use and 4 ' maintenance of the Creek were considered REGIONAL AND LOCAL and incorporated in the study. CONTEXT The San Ramon Creek Greenbelt and Although San Ramon Creek stretches from Parkway Study is a policy document and a San Ramon through Walnut Creek, the component of the General Plans from portion currently under study originates Contra Costa County, City of San Ramon from the Bollinger Canyon watershed in and Town of Danville. The purpose of the San Ramon to the Walnut Creek City study is to provide a guide to land use Limits. The southern limit is the decisions affecting San Ramon Creek; intersection of Bollinger Road and Crow specifically addressing its preservation, use Canyon Road and is confined to the north and development. In order to translate this by the City of Walnut Creek/Contra Costa study into programs and physical County Limits. This ten-mile stretch is improvements, it is essential that a logical generally parallel to Highway 680 until process be followed, progressing from the Crow Canyon Road, where it abruptly general to the specific. The study extracts the goals and policies from the General goes into aneast/west direction. The Plans and translates those into a more Creek's proximity to Highway 680 allows detailed plan which is specific to the San good Potential vehicular access via six Ramon Creek. off-ramps. There is currently very limited pedestrian access. Ultimately, this study is part of a bigger picture, to create a healthy, 30-mile long greenbelt stretching from the headwaters of San Ramon Creek, connecting to Walnut Creek, and culminating in the outfall to To Creek '4 Suisun Bay. Toward that goal, two r.:. f.�_. ....: ......... similar, concurrent studies are being `' ... conducted for the area downstream from Lafayette the south edge of Walnut Creek to Suisun . .. Bay. LAlarn Danville ( �, f ! a ^Sane .s R on Open Space/ Parks ' �• "` .. REGIONAL SETTING MAP �o San Ramon Creek scale 1: 20 000 5 The local network includes several streets Hydrological management goals: that cross the Creek. While the Creek crossings provide potential opportunities a. Use the existing hydrologic information for public access, they also divide the to analyze and make recommendations to corridor for wildlife into many disjointed restore bed stability, channel banks, and stretches. There are several distinct areas reduce flood hazard. of the creek, each having individual features which contribute to their separate Recreational/educational goals: identities. Although the Creek is centrally located in the downtown areas of Alamo a. Design a trail system along the Creek and Danville, most businesses have turned corridor that takes into account existing or their backs to the corridor. In San Ramon, proposed trail systems and avoids the Creek is more naturalized, and several disturbing highly valued habitat areas. of the office buildings have embraced the Creek and created some accompanying b. Explore any educational opportunities employee amenities. along the Creek. One future access improvement to be built, c. Develop accessibility potentials to the which will affect access across Highway Creek, especially in downtown Alamo. 680, is a new vehicular overcrossing at Fostoria Avenue. This improvement d. Provide some areas suitable for pilot reflects the dynamic nature of increased projects such as wildlife/fish habitats, development taking place in San Ramon. bioengineering, creek stabilization, and beautification. GOALS AND OBJECTIVES The San. Ramon Creek Greenbelt and DESIGN PROCESS Parkway Study was prepared to target a specific set of biological, hydrological and The initial phase of the process is the recreation goals mandated by the Task inventory and analysis of existing Force and stated in the original request for conditions, particularly with respect to proposals. vegetation restoration, wildlife habitat enhancement and coordination of existing Biological management goals: and potential areas suitable for a future creekside trail system. The analysis of a. Restore a continuous riparian vegetation existing conditions will identify major corridor (with the exception of the freeway opportunities and constraints that the creek interruptions) from the headwaters in San restoration and trails plan must respond to. Ramon to the Walnut Creek City Limits in Following the inventory and analysis phase order to restore bird and terrestrial wildlife of work, alternative trail plans and habitat habitats. restoration guidelines will be developed, b. Identify and enhance important habitat integrating the requirements of the various areas for wildlife. specialties into common expressions. A c. Remove exotic (i.e., non-native) plant preferred plan with alternative options will material. emerge with a general implementation 6 strategy that will be subject to detailed The Consultant Team, with the assistance hydrologic analysis to be done at a later of Danville and San Ramon staff, held two date. Then the plan will be refined into the public workshops, one presentation to the final San Ramon Creek Greenbelt and Tri-Valley Parks and Recreation Parkway Study. The report also distills Commission and one presentation in front information into issues that will guide of the joint City Councils. Prior to each recommendations for the study area or workshop, ads in the local papers require further investigation. This study, publicized these meetings. At these public maps and text inclusive, is diagrammatic meetings, attendance rosters were and schematic. That is, the study explains circulated to aid in building a mailing list concepts, rather than representing actual of interested persons and thereby broaden things'in detail. It outlines and provides a participation. framework for ideas so they can be considered by others. Ongoing public support will be crucial to the successful implementation of the San Ramon Creek Greenbelt and Parkway PUBLIC PARTICIPATION Study; in working with other jurisdictions to make appropriate connections; in The public was a vital member of the volunteering for creek clean-up days or Planning Team throughout the planning construction; and in pursuing opportunities process, with participation in a series of for funding the restoration and greenbelt public workshops and representation project. through the Task Force. The Task Force was comprised of two = � : creek citizens interested in creekb+; preservation, one staff member from each LL- of the following agencies: Town of54M Danville, City of San Ramon, Contra Costa County, and East Bay Regional Parks District. It is important to note that the Task Force represented diverse ' interests and attitudes in the community. . ;F ` The Consultant Team met with the Task Planning Team at Work Force once a month throughout the planning process to discuss background information, identify important issues and evaluate alternatives. The Task Force has ' been crucial in confirming each of the communities' goals and policies and in recommending additions to the Master Plan. This input from the Task Force will continue to be important in reviewing and later implementing the plan. K' 1 ^Y s��4 t"'rr3t � r,'i<.`,� •�� $ "y' � ; i. Jr L�y: '.9, �•a r3r�r �,y`'c (� ��?.rrr v.�t�'�.. - �, ' R g.1 tri �y,(T'"". � < ya ,r ;•'�.�`�•ttr+ r n:a�F .•F{.lr, t� r nA o y y f'� -.0.T•a�4 .Z' _� r( �' � 'K)��f 1 xTz �fi. .` l� i. ,•R^ss##,yy,••"'_`..-- nc r3 kr.'�.-t �y < � ? .,r '. t `a. ;N�s �:l fyt�„ r .:�1 f L r3 r..' n �? � 'S'. .x +•'-Ir• 11 d' `y ,� r rte } .✓' M: t r^" ems•- }•'` {l. -k. $ 2� a, r4SA. Y �� ' ♦^�.. � -� + r 11C�s Tc a { �� yr+."�`- ns�' .4 r _., f:. s �aK �. pro a.''°� S r': < ;,. r4•�rs'+�rr_r.. rs _ z+.��,�.'.u. f t y,,. Y "'_ r `�.�g �` '41 rG� .A� �YCC.i r.-Zf.,y;:... »>. �"<•F .�.rz<�•is -a'Y`+ � .. L '`�}^� ,w y . s -,� fyr , 3t_X..5i -'�� ,�" .�.✓ t y.rtL' ?�Y) t� r._{ai.-..5� l �=� / L^� �" � <. ¢. - ��'.-t• - '�'er"�-f�'#3�, �vhf it t �di p��{',,�� g •n tt �r�....��dH {i"'°�•�„�.,,. ��t ��-!`,d c ?'tj.cc''."i-.''-�:r� "mbyrrr M — i �^tr Y �'g''Y�t 'J`�A f <•L 'y"'a% :n'•. u. ! '1,rSq+ c''Y f�sf [ YT ` rte• - :. ,r< ems. r.:i.• :aS HISTORY OF SAN RAMON CREEK STUDY AREA There are three recognized periods of early 20th century with the construction of human history represented in the San Danville Boulevard, Hartz Avenue, and Ramon Valley. These periods are: San Ramon Valley Boulevard. American Indian, Hispanic and American. American Indians inhabited the San Ramon In the late 1880's, August Hemme of Valley as early as 4,400 years ago. Those Alamo spearheaded a movement to earliest Indians were ancestors to the convince Southern Pacific to build a Saklan, the small tribe, numbering fewer railroad that would transport the Valley's ' than 1,000 individuals, who occupied the fresh produce, then in great demand in San Valley at the time of first contact by the Francisco. The railroad was completed in Spanish. Evidence of their culture can be 1892. When it ran its last freight run in found in the remains of villages, burial 1976, there was much controversy about sites, and artifacts. While site locations are the abandoned right-of-way. Some wanted ' not made public in order to avoid to make it into a commuter light rail transit vandalism, there is ample evidence of this line, while others wanted to convert it to a culture, including archaeological studies. recreational multi-use trail. In 1990, the first seven miles of the Iron Horse The Hispanic era of California's history right-of-way were paved for a recreational includes the period of exploration of trail extending from Alamo to Danville. Northern California by explorers such as Don Pedro Pages. In 1772, Don Pedro The broad open banks of the San Ramon Pages was sent by the King of Spain to Creek began to show the effects of growth map California, and he camped in the in the 1950's when improved water service Alamo area. Soon after, Alamo became by East Bay Municipal Utility District and the first European settlement in the San service from the Contra Costa County Ramon Valley. Sanitary District contributed to expansion of residential development. The American era begins with agriculture. Farming became the predominant industry Highway 680 was completed from Walnut in the fertile soils of the San Ramon Creek to Dublin in 1965, allowing further Valley, with the San Ramon Creek as the expansion of the valley, attracting main source of irrigation. Adjacent to this corporations, commercial and residential meandering creek are remnants of early development. 1900's farm buildings, fences and orchards. In the familiar grid-like pattern, were the orchards that grew "some of the finest pears and walnuts in California, " according to reports from a century ago. The Creek's west bank was the primary horse and wagon route from Walnut Creek to San Ramon, until it was replaced in the 9 Q ..Fds 1 E� .J•' }�tiL.1 c. F. y T Y'�1;'4�by f��{�,� r. iki 7r2 ti'r@- •;lr{^ a tS � '� f �l•M v �� 'l�i'>ij J'sK'.,f .Y xf'�,�ak.�`�M,�� ti.r4._ -+� � � - y}c �. r„yi •mak �rte k8�•: '� �_ � c41.�y? .� ±d .r� w'b :"2� s �'£?r �•� t' v�. '�r "t.$ �'�,' t'i_ � t ' s �'"� v 3 t`•. r r_ s4 '� � 's.. 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S� x f2 'r57��, t �rYiss � Tmtz "+. •m•cX-�,t--3'r�': tNxp- ." ; r: rt c 4� �7� � .t. ✓ x��; a �k r,�2K' .��' •� < ��,'Nt�,�Y,=r*'F^'�-� ..,�,r �t - * 14,� 4•e i. -,;.k,,.. �yS .� M {.. �iPte,,,2.p5 -X 1..� Y 1 :s• � Y�/-''> -t' (S - �1 e��" y } '�. �� }-I''•'.z'. 1: -,'��„ `R ��,�-7�,++,, x{x,•�Y't°``"1''jrFM•� G � ,r +l[i^�-3,':M' •r C'S t •a i! �.. rrdR1'�iZ.��?@�, "� ,a,yt�'`k�.y� �t .�•�' ��J•ft ti r+�J � �i't v?•y??�. t s l� dh:�. J� i i SURROUNDING LAND USES Objectives of Bollinger Canyon and Crow Canyon Road. The Creek Study Area is dominated This section of the study will describe the by residential development in Alamo and ' present land uses of the Creek and describe Danville, with some commercial in the the physical and visual accessiblity of the downtown core areas. Through San Creek. Ramon, the Creek flows through commercial and office uses and a minor Methods amount of residential. Present land uses were surveyed by foot, The San Ramon Valley Iron Horse Trail is vehicle, photo interpretation and a 13 mile segment of the 31 mile-long information available from Contra Costa abandoned Southern Pacific Railorad right- County Assessor's maps and the General of-way, which extends from Martinez Plans from Danville and San Ramon. south to Pleasanton, linking Alameda and Contra Costa Counties. This recreational ' The physical and visual presence of the trail is maintained by the East Bay Creek was assessed from the major public Regional Park District. Generally the trail areas, including freeway entrances, as well is parallel to Highway 680 and averages as from adjacent neighborhoods and parks, about 1,000 feet from San Ramon Creek. walking down to the Creek, and viewing ' the Creek from above via the ridgetops of *I, . Las Trampas. In addition, known plans for developments within-or adjacent to the creek corridor were reviewed and assessed27, ^may with regard to Creek access and visual I impacts. The land uses in the study area are a mix AK yC' d� of low-density residential, high-density residential, commercial/retail, offices, San Ramon Valley Iron Horse Trail public/semi-public space, and open space as documented on Maps LU I thru LU 8. An east/west trail currently under development by East Bay Regional Park The ownership of the creek is similar to District will ultimately connect Las a patchwork quilt varying from outright Trampas Regional Wilderness to Mt. public agency ownershop to easements to Diablo State Park. Currently, this hiking reservations to private ownership. and equestrian trail begins at the east side ' of San Ramon Creek at La Gonda Way in Setting Danville. It weaves its way over the ridge The San Ramon Creek Study Limits start above Highway 680, crosses Stone Valley ' downstream in Alamo at the Walnut Road in Alamo, and enters Mt. Diablo Creek/Contra Costa County Limits, and State Park at Macedo Ranch Gate. Portions continue upstream as far as the intersection of this trail provide disabled access. 11 The neighborhoods surrounding the Study Danville Area are served by eight schools: two are Diablo Road provides the main entry into private elementary (St. Isidore and San Danville from Highway 680. The Study Ramon Christian); four are public Area downtown contains an unusual elementary (Alamo, Baldwin, Greenbrook pattern of streets that have developed over ' and Twin Creeks), one is a public junior time. The railroad played a significant high school (Charlotte Wood), and one is role in determining land use patterns, and a public high school (San Ramon Valley). diagonal streets crisscross the area close to The Creek also flows through Hap Magee the original railroad facilities. Downtown Park, Osage Park and Crow Canyon Danville has more of a distinctive "Main Gardens. Street" appearance, with two-story wooden buildings and narrow sidewalks. The housing tracts upstream were laid out in Alamo the decades following World War H with Most of Alamo is characterized by narrow streets in loop, lane and court low-density single family homes, with a configurations designed for safety and few vacant lots, some small-scale orchards, sense of identity. and some ranchettes laid out in a grid pattern with a number of cul de sacs. Most San Ramon of this housing was built during the 1950's Recent retail and office growth has and '60's; as a result, the vegetation is occurred in San Ramon and within the quite mature and lends a private, woodsy Study Area, it is primarily office use. appearance. There are two major shopping centers at the intersection of Crow Canyon and The commercial character of Alamo Highway 680. Some office buildings along consists of one and two story buildings and San Ramon Valley Blvd, Old Crow is pedestrian-oriented. 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'" !;•'-or�' Z�,a i �'� C v�-..� 'y,;.nv�,. � �y y s t;� ��<� c r s a- . <3,. .. +` to _ �`"_ .Y?""..� r d ?'s.-'ur' r"`c. � },'• ,- � � '.?+r 1.��. ',`Ys.. arts };; ,,c i...� L'-.It.t '1t' ',•.�qr_',a HYDROLOGY ' Regional Overview San Ramon Creek is one of the major ` _ drainages in Contra Costa County (Figure 1). The drainage area of San Ramon Creek Basin upstream of Rudgear Road near the Walnut Creek city limit is approximately 47.8 square miles. The major hydrologic issues in the proposed restoration of San Ramon Creek ' are channel bank and bed stability, and flood hazard. A variety of bank stabilization techniques have been used on San Ramon Creek. These include engineered and non-engineered structures, and typical of improvements of the 1950's ' and 60's, their sensitivity to the environment is limited. These structures h a vary in their ability to stabilize the channel. In the 1960's, a series of flood control drop structures was constructed in the Creek. These were designed to dissipate hydraulic energy during high flows, and reduce channel incision. The _, drop structures were placed at intervals ` ''' along the Creek to minimize the natural fi stream gradient and concentrate most of the elevation loss at the drop structures ;,• ` themselves. , Where possible, the enhancement plan will increase flood conveyance capability in the Creek. However, it should be noted that w hydraulic data, including computer analysis of channel capacity (HEC-2) was available ' for San Ramon, but not for the Town of ...F Danville or Alamo. While this limitation in existing data will constrain the level of �y detail in the hydraulic aspects of the enhancement plan, it will not affect the conceptual design approaches. Structures on San Ramon Creek 1 15 1 Hydrology ' The hydrologic conditions of San Ramon The peak 100-year discharge at the Creek were most recently summarized by Highway 680 crossing near Crow Canyon the Contra Costa Flood Control and Water Road for the existing condition is 3,500 Conservation District (CCFC WCD) in the cfs, and the projected discharge for Hydrology Report of San Ramon conditions in the year 2020 is estimated as Watershed Contra Costa County, 3,850 cfs (Brown & Root, 1987). California, 1977. Contra Costa County can be characterized Hydraulics and Flood Hazard as a region of meteorological homogeneity. The region has mild, wet winters and hot, Several studies that discuss flood potential ' dry summers. About 95% of the total in the San Ramon Creek are reported in seasonal precipitation of 22"-25" occurs this section. However, neither a during the wet season that begins in comprehensive flood study nor a hydraulic ' October and ends in April. San Ramon analysis of the San Ramon Creek has been Creek flows all year, with dry season low conducted specifically for this project. flows typically occurring between June and Flooding and bank erosion problems occur ' October. in San Ramon Creek downstream of Livorna Rd. Creek banks on the west side Hydrologic analysis provided by the of the channel are nearly vertical and are Contra. Costa Flood Control and Water about 15-20 feet in height. The channel Conservation District for various flood capacity in this reach is only about 7,000 recurrence intervals is shown in Table 1 cfs, which corresponds to the 10 to (Draft EIR, 1986). 15-year flood level. The predicted 100-year flood would have a Table 1. peak discharge of 12,500 cfs and would Flood Frequency Analysis for San cause excessive flooding, as indicated on ' Ramon Creek at Livorna Road the FEMA maps for the area. In the reach of San Ramon Creek downstream of Livorna Road, the floodplain slopes away Recurrence Peak Discharge from the creek toward Danville Boulevard. ' Interval in the Year 2010 Where Danville Boulevard is lower than (years) (cfs) the top of the flood plain, flood water ' could pass over Danville Boulevard and be trapped between the street and the 2 2,400 Southern Pacific Railroad embankment. 10 7,100 This area is lower than Danville 50 10,900 Boulevard, and slopes toward Rudgear 100 12,500 Road. The flood waters would travel in this area until the railroad embankment forces the water toward the existing channel in the vicinity of Rudgear Road. 16 Levee maintenance and protection The existing channel conditions of San measures are subject to a complex web of Ramon Creek Project Area are illustrated permit review and approval by various in Maps Cl thru C8. Federal, State and local agencies. Each of these agencies has a specific charge in Historical Context ' reviewing creek channel and levee maintenance projects. In addition to the San Ramon Creek has had several floods local agencies, the list of agencies having in the recent past which caused overbank jurisdiction include the U.S. Army Corps flow or significant bank erosion. Recent of Engineers, State Department of Fish and damaging floods occurred in January of Game, U.S. Department of Fish and 1982, October of 1962, and December of Wildlife and U.S. Soil Conservation 1955. During the 1982 flood, Service. These agencies will review and approximately 6 inches of rain fell within a provide permits following development of 30-hour period. Overbank flooding the final design plans for the San Ramon occurred downstream of Livorna Road. Creek Greenbelt and Parkway Study. peak runoff was estimated at 7,200 cubic A permit for Section 404 of the Clean feet per second(csf) and bank erosion occurred in this reach of the channel. A Water Act would be .required for flood frequency analysis provided by the ' implementation of the enhancement alternatives. A National Pollutant Contra Costa Flood Control and Water Conservtion District for various recurrence Discharge Elimination System (NPDES) intervals indicate that the peak runoff from permit would also be required for the r enhancement plans which requires that all the January 1982 storm was an event that can be expected to recur approximately public agencies m Contra Costa County once every ten years. take measures to reduce/eliminate water pollution. ` The following sections describe the «t= r existing hydrologic conditions in San Ramon Creek. This information was derived from field observations by foot, vehicle, and aerial photo interpretation. Documentation from Contra Costa Flood Control and Water Conservation District was also reviewed. During the October 1962 flood, over 10 inches of rain fell during a 24 hour period. The scope of the work for this project did Because of relatively low antecedent not include conducting hydrologic or moisture conditions in the watershed, no hydraulic studies, and the report relies on overbank flow occurred this time. available existing data and discussions with However, bank erosion did occur. During the Contra Costa Flood Control and Water the December 1955 storm, about 40 inches Conservation District. A hydraulic study of rain fell during an 8 day period. should be required in the detailed final Personal accounts of this flood suggest that design phase to update the available over 20 feet of erosion took place at one hydraulic data. location near Chaney Road. r 17 t A Draft EIR for the San Ramon Creek channel modification and excavation has Flood Control Project in Alamo between been initiated on the east side of San ' Livorna and Chaney Roads was completed Ramon Creek adjacent to Highway 680, in 1986 by Contra Costa County. and is related to future flood control However, funding for the project is still activities proposed for this reach of the being sought. Some grading activities channel. Existing structures are located related to the project have been initiated near the top of bank at the west side of adjacent to San Ramon Creek in the San Ramon Creek. ' Project Area. Livorna Road to Stone Valley Road, ' Flood hazard is not as critical in the (Map C2) upstream portion of San Ramon Creek as it Between Livorna Road and Stone Valley is in the downstream portion. Where the Road, San Ramon Creek is modified as a channel is deeply incised in the upstream trapezoidal, earth-lined channel with grass; reaches, overbank flow does not occur rip-rap or gunite is present adjacent to during flood flows. culverts, bridges, and two drop structures. The east bank of San Ramon Creek Walnut Creek City Limit to Chaney follows Highway 680. The top of the west Road, (Map CI) bank is bound by structures. One large The furthest downstream section of San culvert over six feet in diameter carries Ramon Creek within the Study Area starts tributary flow from the east side of at the Walnut Creek City limit and follows Highway 680. Between Livorna Road and along the east side of Danville Boulevard. the drop strucure (DS2), the channel is a The channel is a modified trapezoidal modified earth-lined trapezoidal channel. channel with the banks and bed stabilized Channel banks appear unstable in the with grouted rip-rap. There is sackrete in modified reach, with some slumping. some locations. This reach of channel Rip-rap is present in some of the unstable experienced overbank flooding during the reaches. Between drop structure (DS2) and ' 1982 flood. drop structure (DS3), the channel is natural for a short reach with steep eroding banks Upstream of the modified channel, a and some vegetation. bedrock outcrop creates a waterfall that is a prominent channel feature. Bank Upstream of drop structure :(DS3) to Stone modifications continue upstream with Valley Road, the channel has sections of sections of asphalt and grouted riprap steep eroding banks and some vegetation, between bedrock outcroppings. some modified reaches with rip-rap, and ' low terraces in the channel on the inside of Chaney Road to Livorna Road, meanders. Structures stand near the top of (Map Cl) bank in this reach. Between Chaney and Livorna Roads, the channel banks are mainly natural with Stone Valley Road to El Portal, (Maps numerous inconsistent applications of bank C2 & C3) protection techniques. Bank conditions Upstream from Stone Valley Road to range from rip-rap, gunite, and sackrete to Sandra Court, the channel continues with stable or unstable vegetation. 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Y# 'r '�" 6' t Par: ' � .; i .t r... . 41 1 �c $� V ' , six - z as z - #a, xW ice, _ xf ,b & F tZ R: � �$ �I"— � , .41 '� f' w' f f .i R� Z ` k.4, .y& y}s f ��k h . . :,' , - .". , I k * R y ,z % .. M l-'-w—f ff 'sad�� Naw. _ :Y✓ .. a ��, ! f A`f q r.. 1. s g$ X3,1..ry .�''a EF` :uw�S .5.".' R�3 $ 6>i.• "ate'; 3 t , ? 11 HNII HJ1tlW i . reach. The channel has been modified Highway 680 (at Charlotte Wood with the drop structure (DS4) just upstream School) to Sycamore Valley Road, of Sandra Court. Further upstream of the (Map C5) drop structure (DS4), the channel banks Between the Highway 680 crossing and the are steep and unstable to the next drop drop structure (DS 10), the banks of San structure (DS5) near Hap Magee Park. Ramon Creek are mostly modified as a Broken concrete debris exists in the trapezoidal earth lined channel with some channel and a pipeline crosses the Creek at areas of natural slopes and vegetation and an elevation corresponding to the top of some rip-rap. Just upstream of Highway the bank near the drop structure (DS5). At 680, a deeply incised and actively eroding Hap Magee Park, there are numerous low drainage channel enters San Ramon Creek. terraces present on the inside of meanders. Immediately downstream of the drop structure (DS 10), the channel has been Upstream of the park to El Portal, near the modified with concrete walls and access Danville/Alamo city limit, the channel is ramps. deeply incised, with steep banks. Some of the banks are vegetated, while some are From the drop structure (DS 10) to the stabilized with modifications such as Sycamore Valley bridge upstream, the rip-rap and grouted rip-rap. trapezoidal channel is lined with grouted rip-rap. Grass-covered, fine grained El Portal to Diablo, sediment deposits exist in the channel (Maps C3 & C4) stream at this reach. These sediment Upstream of El Portal to the drop structure deposits would be likely to flush out (DS7), a fine grained sediment deposit has during a high-magnitude flow. accumulated adjacent to the low terrace. Immediately downstream of the Sycamore Just upstream of the-drop structure (DS'), Valley Bridge, a tributary drainage enters channel stabilization techniques include San Ramon Creek. grouted rip-rap. Channel banks are vegetated and relatively unstable with some Sycamore Valley Road to El Capitan bank erosion and undercutting further Drive, (Maps C5 & C6) upstream to the next drop structure (DS8). The channel banks are steep and have been Bank modifications include gunite, rip-rap, stabilized using rip-rap and grouted rip-rap and hydromulch on the recently graded for approximately 100 feet upstream of bank. Upstream of the drop structure Sycamore Valley Road Bridge. Upstream (DS8) to Diablo Road, the banks are steep, of the rip-rap section, the channel banks unstable, and vegetated. are well vegetated and relatively stable to Osage Park. ' Diablo Road to Highway 680 (at Charlotte Wood School), At Osage Park, there is.a significant drop (Maps C4 & C5) in the channel elevation from the drop ' Upstream of Diablo Road, the channel has structure (DS 11). Upstream of the drop been modified with the drop structure structure (DS 11) to El Capitan Drive, the (DS9). The channel upstream from drop banks are well vegetated and relatively ' structure (DS9) Highway 680 adjacent to stable as the Creek meanders around the the Charlotte Wood School is earth-lined north side of Osage Park. with some bank undercutting. 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'� fin'. ri <f R• qs y x Y � g, : '4.rm +>. x -,a m r X Qk g�" w� € zYe�ua•„ �t! ,�`z�-� � � w° �` � � � ,�'•L„ ��ts.� .�'� � ��E °;�a ism�� f `�.",.," ,°z., { x�.w6,r y>' � �s.:�.� '� "�k`�� a� ��, # ,�'' x: .1 Own mi PA WI!Ed _ � � a x3* a3r•"r«.f z•:'O a,."' �. mr _ �° � f�`.� r mow, P a w aQ+ w ass Mv mum a a,� ig L"` s�>:®' ;�}d `,ax' e '€ All 510 ,>w • yr �, r' ,,. L k ��. L" yx` a,.�.#om z'k ,xie = 3'y7 . .Sz •?. 5r �..r •: a.F.yta ;s a.... ... 3fZ1HaLVW Sim im M M a n � y I WYm„ 9Ag �� > ma � Pte' �II� 1 kW y'"� •,� ..e, �y�i�•4mw��ry 1 � �� ( r t rP f Yw" a Doi A 17 { MY— a" i h OBJ a� lol Existing Conditions of San Ramon Creek 20 EI Capitan Drive to Highway 680 A major constraint to enhancement in the P g Y J (Maps C6 & C7) downstream portion of San Ramon Creek The channel opens up to relatively is flooding. Existing structures adjacent to low-gradient grassy banks upstream of El the Creek prevent any widening of the Capitan Drive and the confluence with channel to increase flood conveyance. Cow Creek to a few hundred feet Any enhancement alternative proposed will downstream of Greenbrook Avenue. From be designed so that existing conveyance is Greenbrook Avenue to Camino Ramon, the not reduced. channel banks are well vegetated and It would be expensive to replace existing relatively stable. concrete, gunite, rip-rap, and sackrete Upstream of Camino Ramon to the drop bank stabilization structures with structure (DS 12), the natural channel is alternatives. Existing bank protection is incised and banks are steep and eroding. most likely in the creek because a bank From the drop structure (DS 12) to stability problem existed. Removing the Highway 680 San Ramon Creek flows existing bank protection will not remove g y the existing bank stability problem and the through a modified earth lined channel study does not suggest that existing bank with some gunite along the banks. protection be removed without an effective alternative. Alternatives recommended will Highway 680 (at Crow Canyon Road) provide bank protection as well as habitat to Bollinger Canyon, value. (Maps C7 & C8) The upstream end of the Study Area from the Highway 680 crossing near Crow Opportunities to improve bank stability will be combined with efforts for resource Canyon Road to Bollinger Canyon, San Ramon Creek is deeply incised with a bank enhancement and public access. In height of approximately 50 feet in some locations where the Creek has a constrained right-of-way, there is an locations. Some banks are nearly vertical and are eroding due to undercutting at the opportunity to replace or modify existing base of the banks. Low terraces exist in bank protection. some of the wider sections in this portion of the channel. There are a number of Vegetation may be incorporated into the commercial buildings that are close to the design for bank stabilization in locations top of the bank in most of this reach. where the Creek right-of-way is not constrained, and where the width could be Hydrologic Constraints and increased to accommodate the increase in roughness associated with the vegetation. Opportunities Streamside vegetation would provide shade ' to lower temperatures and keep the channel Hydrologic constraints and opportunities bottom clear of brush vegetation. Exotic that affect the enhancement of San Ramon vegetation may be replaced with native Creek are related to flood hazard, erosion, vegetation if roughness is not increased. and sedimentation and include the Hydraulic modeling would be required in following issues: order to ensure that flood hazard is not increased by the conceptual enhancement designs. 21 W s6 ,� � I [- U o = d U V _ Ccc _ y = 12 3� 'x 15 1W ti M= O uayu <aH = v =.o,! O e 1 m0 s < > = - > V I , 2IS �C rrL C G ` yy�F a y�`- y■ g`.'a e � Rol + a II1'}''a/({�`[p�'J� U (�) _ y`I �`1� A`V � �� [ �CyLLn y�EX� 69 nti.w Y .� U�® + �O�I u'� ~O C W5 Z .I■1 V1 Ci d' a X.7«1a Hill o1i ME [-m�s�4 W U j j Y r,: F, 3 ! ga„: k'3 i N % n'yb uA r � 0�� „,�..,.;:. �:�, Y� — I.."....0, ,,, -.1 :::::::::.V�, .,�� i .::, z z�� 'i. � i:: ,11- 1 yn�7�IM .. ::�;��:in, .... __ - . 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I > : xa w ,�„ :tom'x '�' �. �� GQt�� ; ':' "� .�,zy.� .s• _ � � €. � '�' �.a .�x� � �` zVe '�:� � z _. �`V� "a ✓ .as -a �n:n �, F<-,� � G�F ;� gz�:.,�',, '� � 'E&" , �' :� —— _� •�� a :'fie,�� - �'ax $ � 6 :. � S f i ' Channel incision will continue to REFERENCES destabilize banks in the upstream portion of the watershed and require further bank Brown & Root USA, Inc. and David L. stabilization. Existing drop structures Gates & Associates. 1987. The City of minimize incision of the creek bed, but San Ramon Creek Corridor Plan. ' upstream of the structures, it is reflected as a low flow creek. Brown and Caldwell, 1985. San Ramon Valley Reclamation Project, Project Fine grained sedimentation in the channel Report. Dublin San Ramon Services may reduce channel capacity during District, East Bay Municipal Utility moderate flood flows. However, the District, City of Pleasanton, Alameda sedimentation would probably be flushed County. out during high-magnitude flood flows. Contra Costa County Flood Control and There is an opportunity to modify existing Water Conservation District, 1977. drop structures with a low flow by-pass to Hydrology Report San Ramon Watershed, allow improved water quality during low Contra Costa County, CA. For Flood flow periods when water is backed Control Zone 3B. upstream of the drop structures. Contra Costa County Flood Control and Public safety must be taken into account in Water Conservation District, 1986. Draft developing a trail plan and a resource Environmental Impact Report for the San enhancement plan. Ramon Creek Flood Control Project Between Livorna and Chaney Roads in Alamo, CA. FEMA, Revised 1990. Flood Insurance Rate Map. City of San Ramon, CA., Contra Costa County. 1 j22 1 2p J1 A y.Y� •54 ''`sdvt �.}� „rr r G �,')'�3 +Y•S•..uE't..��#t.�m1•( `r w u � � At i•"3✓'. tG (' 4J,�. ff' -�• o- '� >1n a � '?'t IAN �� r. wi ��9 Lt) ,-• ✓ ��F. > t yJJ ti; *fir a �o-"d� ' a �� r•�� T` `t� h.. .sem}�',r t � A 'S�!q:,. ,�'"�' � ' 'Ark, )•1 J?-o-'E �1 (yn'�� S .ryi �,y �fi`�. G3� 1hY.c h r t ,fi. s'irF �•- �S yil1 'V � .moi YY�''CYF :. --.i� �` �.'y �h.. - f..e ,` ' .r�y�1 _ ♦ xi alk.�`.' xa �i:;` � t u ' .'�.�,, •v Z t''T' r�--�4�` moi` .h •�. `��2- - a.ai�r, i. 5.��'Y y'�"��'4 r _ 1 �,l �� ` �4'rl ,nY r- '�.6� � t �� '�ti "f �,,. z�yj47 1. -!v1 .{ 7 � ••r�� F J i N�'� �� ')�" r L.: �� + � 1 L{ )� ��})49,F��' i�,Pj ..,,�i�,s„i. - T j-,tC a)3��S�.Y �"is `t< } { S—• ^c :.�• L`��, F r✓ K NYJ4�. �3. � '. ,>Y.r 7 �✓�. M,., T � MF -j`Y•cC'' {J .+ �.,�,�v,-"�7, .�rr�y�t{11"r ��.�; �c X..•.,. � t r �' �y.'�',�,',es��i.e•t�'t^ r i�'.+S a<� r � 4�F r r"�. t"✓44 `�" �? .'^.-fir + � �� <n L'•.f f. s a,'R ��1S _ '2`}4'�. ) t• ?r U- 'a.+' Mn Std" V''�' T 7r S`ry °� a 7 ) "�r tFf•S��y .). �,,l�:tn� �1�,� `r 1 ` r h' 4 �t {i�� - '?�.� �� xx su �tt�.C`��.r�;a< } § Jrr� '✓-��t r�. �y )i.? R �� s i Mr : .r.}jt br Y, � rr y�'t •/••.-. '�3tt.' i �� BIOTIC RESOURCES Objectives Significant localities of invasive, non-native plant species were also noted on The study for the enhancement of the the project maps. riparian and recreational resources along San Ramon Creek included an assessment Wildlife resources and species observed in of biotic (vegetation, wildlife and the field were noted on the project maps. fishery/aquatic) resources. The goals of the Binoculars were used to aid in assessment were to determine the existing identification of species. The California ' conditions of the stream corridor and, in Natural Diversity Data Base was consulted conjunction with other members of'the to obtain information on wildlife species of planning team, identify constraints to, and concern in the study area. The Walnut opportunities for, enhancement of riparian Creek Restoration and Trails Master Plan resources. (John Northmore Roberts and Associates 1990) was reviewed for additional Methods information on wildlife use in the study area. A list of observed and predicted The biotic resources along San Ramon wildlife species is Table 2. ' Creek were investigated during December 1991 and January 1992. The Creek's The fisheries and aquatic resources of San resources were surveyed by foot, vehicle, Ramon Creek were determined through and aerial photo interpretation. Attempts literature review and limited field were made to field check each area. reconnaissance. The stream was assessed However, where access was not possible, at a general level with regard to habitat vegetation and its corresponding value to types, substrate and shade. Significant wildlife, was assessed through aerial photo resources, including barriers to migration, interpretation (1"=200', photos dated were noted and mapped onto project base ' 10/30/91). maps. The vegetation along the Creek corridor Setting was categorized into plant communities based upon species composition and San Ramon Creek is a tributary of the community structure (modified from Walnut Creek/Pacheco Creek drainage, a Preliminary Descriptions of the Terrestrial watershed encompassing approximately Natural Communities of California, 183 square miles of Central Contra Costa Holland, 1986). Plant species observed County. San Ramon Creek has historically during the field work were noted and are supported a diverse and varied corridor of listed as Table 1. Significantly large native riparian vegetation. As a result of trees and tree groves were mapped onto extensive residential and commercial project base maps. The California Natural development over the last forty years, Diversity Data Base (CNDDB) was significant vegetation has been removed consulted for information on plant species and portions of San Ramon Creek have of concern within the Study Area. been further altered for flood control. 24 Despite these pressures, riparian vegetation . The arroyo willow riparian community continues to dominate most of the creek inhabits the edges of the streambed, sand corridor and provides valuable habitat for bars, and lower bank slopes of the Creek fish and wildlife species. where winter flooding is common. The vegetation, dominated by arroyo willow (Salix lasiolepis), red willow (S. Vegetation Resources laevigata), and sandbar willow (S. hindsiana), is characterized by its brush The vegetation along San Ramon Creek is and thicket-like growth habit. Since winter comprised of a mosaic of plant creek flows often inundate these areas and communities that reflect the various either scour away the vegetation or allow environmental conditions of the Creek as for sediment deposition (e.g., create well as past natural and human sandbars), the willow riparian community disturbances (e.g., flood control measures, is considered an early successional (or residential and commercial development, pioneer) community and is often composed park projects, and flood events).. of young shrub-like trees. Seven plant communities were observed along San Ramon Creek, of which four are types of riparian habitat. The riparian communities include arroyo willow riparian, cottonwood-willow riparian, valley oak/coast live oak riparian and " mixed riparian. As depicted on the vegetation maps, the riparian plant Arroyo Red ' communities are the-dominant vegetation willow willow resources along the Creek corridor. Other plant communities are freshwater marsh, Other areas along the creek support ornamental landscaping, and vegetation dominated by a mixture of grassland/ruderal. willow and Fremont cottonwood (Populus f remontii) and are distinguished as Riparian Plant Communities: The cottonwood-willow riparian forest. The presence of four types of riparian plant trees tend to inhabit the lower and communities along the Creek reflects the mid-level portions of creek bank. ' various environmental conditions found Associated plant species include box elder there. Factors that influence the (Acer negundo ssp. call f ornicum), distribution and composition of riparian plant species include: proximity of roots , to water, soil type, intensity and frequency of winter flooding and bank scour, ability of the plants to disperse seed, species tolerance to competition for sunlight, and past land disturbances. Box CI er y Fremont Cottonwood 25 California black walnut (Juglans hindsii) (Fraxinus lati folia). Non-native trees of and non-native species of black locust eucalyptus, black locust, and (Robina pseudoacacia) and tree-of-heaven tree-of-heaven are also common within this (Ailanthus altissima). Black locust and ' habitat. Within this community tree-of-heaven, as non-native species, are designation they are small percentages of aggressive competitors with the native willow and cottonwood along the lower flora. Their ability to invade disturbed bank slopes.. areas and crowd out the native trees and shrubs is a detriment to the health of the In locations along the Creek where there riparian community. are a number of co-dominant tree species within the riparian corridor, the Large portions of the riparian vegetation community was designated as mixed along San Ramon Creek are composed of a riparian forest. Typical species include mixture of valley oak (Quercus lobata) and scattered willows, cottonwoods and alder i (Alnus rhombi f olia) at the toe and lower bank slopes, a mixture of black walnut, box elder and black locust at mid bank and � coast live oaks, buckeye, and valley oaks rooted along the upper slope. Shrubs plants common to these communities include California blackberry Valley Oak Coast Give Oak (Rubus ursinus), toyon (Heteromeles arbutifolia), California rose (Rosa coast live oak (Q. agri f olia) and are californica), coyote brush (Baccharis distinguished as valley oak/coast live oak pilularis ssp. consanguinea), snowberry riparian forest. The trees within this (Symphoricarpos alba), creek clematis community tend to be rooted along the mid (Clematis ligustici f olia), and poison oak to upper bank slopes and along top-of-bank (Toxicodendron diversilobum). Common areas as they are generally less tolerant of herbaceous plants include mugwort prolonged inundation by creek flows. (Artemesia douglasiana), wild oat (Avena Associated tree species include black barbata), poison hemlock (Conium walnut, buckeye (Aesculus californica), maculatum), and wild rye (Elymus sycamore (Platanus racemosa), bay glaucus). Non-native plants include (Umhellularia californica) and ash periwinkle (Vinca minor) and German ivy. Nil Buckeye Sycamore Toyon Coyote Brush 26 Freshwater Marsh: Freshwater marsh corridors. The plantings often are part of vegetation is located in and immediately or encroach into the riparian corridor. The adjacent to the water flow of San Ramon dominant trees and shrubs include blue Creek. Plant species include cattail gum eucalyptus (Eucalyptus globulus), (Typha sp.), umbrella sedge (Cyperus coast redwood (Sequoia sempervirens), esculentus), rush (Juncos sp.), watercress tree-of-heaven, black locust, cedar (Cedrus (Nasturtium of ficinale), rabbitsfoot grass sp.), oleander (Nerium oleander), (Pol_ypogon monspeliensis) and other pyracantha (Pyracantha sp.) and pine ' herbaceous plants. Occasionally, young (Pinus sp.). Some of the plantings include willows and cottonwoods are found native plant species of toyon, coast live growing within the water. The invasive oak and valley oak. non-native giant reed (Arundo donax) can be found within the freshwater marsh Plant Species of Concern: No rare, habitat when it is rooted at the toe of the threatened, or endangered plant species bank. have been recorded within the riparian Grassland/Ruderal: Several bank slopes corridor of the Study Area (CNDDB, iwithin the study area are dominated by 1991). The valley oak, while not rare, is a grasses and other herbaceous plants. Due species that has been reduced in abundance to the disturbed nature of these banks in several areas of California. It is on the (modified banks for flood control), the California Native Plant Society's "watch harsh substrate (rock covered bank slopes), list because the species warrantsmonitoring. The valley oak is a dominant and the prevalence of non-native, weedy component of the riparian vegetation species, the vegetation is often referred to within the Study Area. as ruderal. Typical plant species include field mustard (Brassica campestris), poison hemlock (Conium maculatum), perennial ryegrass (Lolium perenne), bristly ' ox-tongue (Picris ecioides), fennel (Foeniculum vulgare) and wild oat (Avena barbata). Invasive non-native plant species of particular management concern include yellow star thistle (Centaurea solstitialis), milk thistle (Silybwn marianum), periwinkle, German ivy (Senecio mikanioides), pampas grass (Cortederia selloana) and giant reed. Ornamental Landscaping: Plantings of non-native plant species have occurred throughout the San Ramon Creek corridor. The plantings are most prevalent along the top-of-bank adjacent to residential and commercial development, along roadways and along flood control maintenance 27 ' Wildlife Resources Despite the impacted nature of San Ramon Creek in the Study Area, the Creek ' Riparian forests such as those present in represents a valuable wildlife resource that the San Ramon Creek Study Area provide supports a variety of wildlife, including some of the most valuable wildlife habitats several wildlife species of concern (i.e., in California.This high value is created by: State and Federal threatened and (1) the presence of surface water; (2) the endangered species, and State species of presence of deciduous trees that support special concern). Factors that contribute to large populations of insects; (3) the variety its high value include the presence of of niches for wildlife due to the complex mature riparian forest vegetation, a habitat structure; and (4) the high degree perennial water source, and proximity to 1 of habitat edge (edges where two habitats adjacent open space areas (e.g., Sugarloaf meet support use by many species). Recreation Area and the corridor's relative continuity with Bollinger Canyon). In The importance of the riparian habitat is addition, the Creek serves as a refuge for further underscored by its limited statewide wildlife from the largely unsuitable habitat distribution. Due to its inherent high conditions of adjacent urbanized areas. wildlife value and limited distribution, riparian habitats are protected resources of Riparian Forest: Significant riparian the State (CDFG). The riparian wildlife features in the Study Area include mature habitat values of San Ramon Creek in the valley oak, coast live oak and willow Study Area have been greatly affected by trees, and willow thickets, as well as other vegetation.removal and channel features like snags and steep-sided cliffs modification for flood control and ongoing with cavities. The oaks produce acorns flood control maintenance, and extensive which are consumed by many wildlife urban development along both banks. species, provide nesting and cover Riparian habitat in the Project Area vanes substrate for cavity-dependent wildlife. from sites denuded by flood control The willows and other deciduous trees practices to areas supporting mesic forests support an abundance of insects and are with abundant understory, freshwater especially important for migratory birds. marsh plants and perennial surface water. Steep-sided banks offer nest and roost sites for kingfishers and swallows. For much of the Study Area, wildlife use of the Creek is characterized by species Representative amphibian and reptile that are typically associated with disturbed species in the riparian forests of the Study urban environments, as well as Area include California slender riparian-associated species. Wildlife salamander, California newt, arboreal ' species abundance and diversity will vary salamander, pacific treefrog, western toad, with the degree and type of vegetation southern alligator lizard, western skunk, present. Habitat values are highest where western fence lizard, sharp-tailed snake, the riparian vegetation has been ringneck snake, common kingsnake, and comparatively undisturbed, and canopy and western aquatic garter snake. understory cover is dense and continuous. 28 Breeding birds of the riparian forest important corridor of movement for include red-shouldered hawk, red-tailed wide-ranging species such as coyote, red hawk, great horned owl, California quail, fox, striped skunk, raccoon, Virginia opossum, and black-tailed deer. San Ramon Creek is especially important in this regard, since it connects Walnut Creek with the relatively undeveloped Bollinger - Canyon area. 7 Freshwater Marsh and Aquatic Habitat: San Ramon Creek is a focal point of wildlife activity because it offers Red-shouldered year-round water, a rare resource in the Hawk Great Horned Owl Study Area. Surface water provides Nuttall's woodpecker, song sparrow, opportunities for drinking, bathing, northern oriole, common bushtit, warbling foraging, and reproduction for species vireo, house wren, Bewick's wren, violet requiring aquatic habitats for breeding. igreen swallow, pacific-slope flycatcher, scrub jay, chestnut-backed chickadee, plain Freshwater marsh vegetation provides ' titmouse, white-breasted nuthatch, cover and a food base for the diverse black-headed grosbeak, brown towhee, aquatic invertebrate fauna that form the rufous-sided towhee, Wilson's warbler, base of food chains. The freshwater marsh ' yellow warbler and orange-crowned supports a distinctive fauna, where it warbler. Common merganser and wood occurs adjacent to reliable ponding areas. ducks may nest where suitable cover and mature cavity-bearing trees occur adjacent The Creek's in-channel freshwater marsh to in-channel ponded areas. Certain steep provides habitat for aquatic amphibians and banks along San Ramon Creek are reptiles including California newt, pacific evidently used as roost and/or nest sites for belted kingfisher. r t \ d r' ';x Wood duck - Belted Kingfisher In addition to providing forage, cover and California Newt denning sites for a variety of smaller treefrog, western toad and bullfrog, as well mammals, such as vagrant shrew, as California red-legged frog, foothill broad-footed mole, Botta's pocket gopher, yellow-legged frog and southwestern pond brush rabbit, fox squirrel and deer mouse, turtle. All of these wildlife species are of San Ramon Creek functions as an concern (refer to Wildlife Species of ' 29 r Concern). Due to the inherent high value these sites are often near the surface water to aquatic-breeding wildlife, especially they require for reproduction. Other ' those that are considered to be sensitive by insectivores include reptiles such as resource agencies, ponds are considered to western fence lizard and ringneck snake be significant resources. and gopher snake, and mammals such as the ornate shrew and broad-footed mole. The freshwater marshes, especially in areas The ruderal/grassland is used extensively supporting dense vegetation near ponds, for foraging by the house finch, American may support breeding by mallards, and lesser goldfinches and mourning dove. pied-billed grebe, American coot, Red-winged blackbirds may nest in areas green-backed heron, common yellowthroat supporting tall vegetation. Aerial-foraging and marsh wren. In fall and winter, species that occur over this habitat include migratory and wintering waterbirds such as barn, violet-green, tree, cliff and snowy egret, Virginia rail, sora, common rough-winged swallows, and little brown snipe and greater yellowlegs are myotic, California myotis, and western representative users of this habitat. pipistrelle. Few mammals are restricted to or Ornamental Landscaping: The various dependent upon freshwater marsh/aquatic non-native trees and shrubs provide environments. One such species, the nesting, foraging and cover for many muskrat, is predicted to be present in San species of birds. Due to their height and Ramon Creek. However, the freshwater dense canopy cover ,eucalyptus trees offer ' marsh provides a prey base for predators excellent nesting, roosting, and/or perching including raccoon, Virginia opossum, sites for raptors such as the turkey vulture, striped skunk and red fox. red-tailed hawk, red-shouldered hawk and ' great horned owl. American crows also Grassland/Ruderal: The interspersion of use eucalyptus groves because of these ruderal and grassland, together with the habitat traits. A variety of flycatchers, close proximity of urban landscapes, including pacific-slope flycatcher, creates a habitat that supports species olive-sided flycatcher and western characteristic of undeveloped grasslands, as wood-pewee use eucalyptus trees for well as species typical of weedy urban lots. nesting. Bird species abundance and Depending on the condition and location of diversity in this habitat is probably highest this habitat, the ruderal/grassland provides during fall migration and in winter, when habitat for rodents, including Botta's the flowering trees provide valuable forage pocket gopher, California meadow vole, for migrating, resident and wintering birds, house mouse and western harvest mouse. such as yellow-rumped warbler, ' Consequently, these fields are foraging Townsend's warbler, yellow warbler, sites for mammalian predators such red fox orange-crowned warbler, Allen's and striped skunk, and raptors including hummingbird, and Anna's hummingbird. ' red-tailed hawk, and American kestrel. This habitat supports numerous The other non-native trees and shrubs are invertebrates, providing a prey base for used as nesting sites by northern amphibians. Western toads and pacific mockingbird, scrub jay, American robin, treefrogs use rodent burrows for refuge; Brewer's blackbird, mourning dove and ' house finch. 30 Wildlife Species of Concern: Eight Fisheries and Aquatic Resources sensitive wildlife species have been identified as known or potential significant Habitat Conditions: The aquatic habitat users of the Study Area and vicinity, based in most of the Study Area is dominated by on literature review, accessing the the presence of the flood control drop California Natural Diversity Data Base, structures described in Section IV of this and field surveys. Significant users are study. The alteration in stream gradient defined as those species that use or caused by these drop structures results in potentially use the study area and vicinity the formation of long, slow-water areas as breeding habitat, or commonly occur in upstream of each drop structure. Natural the study area and vicinity as non-breeders. heterogeneity in the form of alternating ' These State candidate species for listing riffles and pools (fast- and slow-water and California species of special concern. habitats) is lost. This in turn causes a reduction in fish species diversity as well Table 3 summarizes our understanding of as a loss of diversity and abundance of the status, habitat and occurrence in the aquatic insects, and conditions often study area of the following sensitive favoring introduced fish species at the species: California red-legged frog, foothill expense of natives. yellow-legged frog, southwestern pond I turtle, sharp-shinned hawk, Cooper's This condition prevails in much of the hawk, merlin, willow flycatcher and Study Area. In many sections, vegetation yellow warbler. The actual status of many has been removed to increase water I of these species on the site cannot be conveyance capacity. These areas are determined without more extensive field managed with abatement programs which surveys. keep the stream channel and riparian corridor free of emergent vegetation. The effect on the Creek is a loss of cover for fish, a reduction in the availability of I terrestrial insects utilized by fish for food and a loss of shade which results in summer water temperatures too high for ' some native fishes. Fish Populations: In October 1981, televen fish species were collected within the study area (Leidy, 1984). Sampling Yellow warbler conducted in September 1983, autumn 1986 and September 1990, yielded seven, six and ten species respectively (Barlow, 1991). These species, the years in which they were captured and status (native or introduced) are listed in Table 4. No sampling was included in the current study. 31 i ' At present, steelhead (Oncorhynchus oaks, and toyons have established naturally mykiss) migrate out of Suisun Bay and in the top 1/3 of the channel slope (above attempt to spawn in the lower five miles of the rock-lining). Shrub plantings are a Walnut Creek. Attempts are being made mixture of native and non-native species, downstream of the current Study Area to including toyon, bottlebrush, ceanothus, improve habitat and facilitate passage for and strawberry bush. Herbaceous these migrating salmonids. Therefore, an groundcovers are limited to scattered evaluation of these elements is included occurrences of periwinkle and annual ' herein. grasses. The channel bottom is most devoid of vegetation; however, there are scattered occurrences of freshwater marsh vegetation in the form of water-dependent 14 rushes and rafts of cattail. The channel from the area near the falls to Chaney Road is more typical of a natural riparian Steelhead corridor; oak riparian and mixed riparian plant communities are present. Trees of oak, box elder, big leaf maple and ash as BIOTIC RESOURCES BY well as native shrubs and grasses (e.g., STREAM SECTION California rose and purple needlegrass) are growing amid the rock outcroppings. Arroyo willow riparian habitat is present Rudgear Road (Walnut Creek City along the water's edge near Chaney Road. Limit) to Chaney Road (Map VI). This section has been modified by previous Wildlife: In general, this section of ' flood control activities and for much of its stream possesses low habitat value for length has limited biotic resource value. wildlife. Riparian forest habitat is absent The channel, mostly rock lined and/or from the banks and trees and shrubs are ' grouted rip-rap, confines the vegetation to limited to the top-of-bank, but do not form the upper portion of the bank slopes and to continuous cover. They are mainly used selected top-of-bank areas. The streambed as perch and/or nest sites for birds that ' is sealed with grout such that virtually no adapt well to urban landscapes such as natural substrate exists from Rudgear Road ruby-crowned kinglet, yellow-rumped to approximately 500 feet downstream of warbler, northern mockingbird, American ' Twelve Oaks Road. robin, bushtit, scrub jay and house finch. Instream marsh vegetation is limited to Vegetation: The vegetation is dominated minor occurrences along the shoreline, and tby upland landscaping in the form of the stream substrate is comprised of plantings along the city roadways and concrete armoring. Waterbird and flood control maintenance roads. Common amphibian habitat is limited because of the ' trees include non-native pine, eucalyptus, lack of marsh vegetation for cover, juniper and pepper; native trees include breeding and forage, and the lack of a ' valley oak, coast live oak, and scattered natural substrate which would support a Fremont cottonwood. Several young productive invertebrate fauna that serves as seedlings of native valley oaks, coast live the base of food chains. 32 Fisheries: The artificial concrete box elders inhabit the toe of the channel substrate makes the Creek here unsuitable and mid-bank. Native coast live oaks ' for fish since it provides little if any cover, intermix with ornamental plantings of pine, feeding habitat and spawning habitat. The redwood, oleander and black locust along pool at the base of the natural bedrock the top of the west bank. Large valley chute/falls is confined on both banks by oaks grow along the upper portion of the vertical concrete retaining walls. The falls east bank, yielding to the grassy slope extend upstream for approximately 200 leading to Highway 680. There are feet and are approximately 15-20 feet high. several large-sized tree groves along this It appears that this natural feature would section of creek; valley oak, coast live oak ' be a barrier to upstream steelhead and cottonwoods over 30" in diameter migration. At low flows, there is not were noted. A grove of large-sized sufficient depth for adult steelhead to eucalyptus grow near Livoma Road; the ascend the falls. At higher flows the falls largest trees are over 60" in diameter. would likely be a velocity barrier due to Also near Livorna Road is a stand of the the lack of resting areas. non-native, invasive giant reed. Other vegetation resources include freshwater i However, since steelhead were recorded marsh plants that grow within the shallow historically further upstream in San Ramon water and along the toe of the channel. ' Creek and its tributaries, passage beyond . this point once must have been possible. Wildlife: The riparian habitat consists of The concrete retaining walls downstream canopy trees and relatively continuous low of the falls now concentrate flow. It is to moderate understory vegetation. The conceivable that before the walls were forest is expected to receive use by wildlife installed, high winter flows spread into the commonly occurring in urbanized Creek's flood plain below and adjacent to landscapes (i.e., urban forests). The the falls providing slow backwater areas. narrow width of the corridor probably This would have made it possible for adult precludes use by riparian-obligate wildlife ' steelhead to circumvent the falls and species, as it creates an unsuitable interior continue upstream. micro-climate and is ineffective in buffering indirect impacts from the There is less than 10% shade throughout immediately adjacent residential area. A most of this Creek section. Only at and eucalyptus grove near Livorna Road may upstream of the natural falls is there serve as a nest/roost site for raptors. Pools ' sufficient remaining riparian vegetation to in-this section are highly valuable for provide fair shade (approximately 30%) for amphibians and aquatic reptiles, due to the fishery resources. overhead cover they provide from shrubs and canopy trees. Chaney Road to Livorna Road (Map VI) Fisheries: The substrate in this section is ' Vegetation: The riparian corridor within mainly sandstone bedrock. The aquatic this portion of the Creek is comprised of conditions include a series of pools and cottonwood-willow and oak riparian forest. riffles; the pools are deeply incised into the Willows (arroyo, red and sandbar) sandstone and are up to six feet deep. cottonwoods and a few scattered alders and Shade in this section is fair to good at 33 � nn 1.2 IL za _ �"'a cu •> E yyCW &. Y p�1z O A]V`n Y,z O Q u✓. Z C - ` V1 {� Y < f W rA0� - U Y;r, maGa3r ctS'23- EL-Oe'aha v x rt e l yp ,N„P a �� ' «� �`. �� `• y, � ,'�s BAR$ q +sa � 9 � �aY" nix�� " '�d a a o � �..� I �a,.'H ,'� ��r• �s �' i x.. t v.k:: 'O jjC�.r�•^' ...—� \ a: !r�'"Y+a '�`: � � fax �r�^.� , y Me rj a a Cc MCI a •y '� We`o` ,oma •� � : �� CR�AY�.: �x ��' ' ' Y a Vs .ke m e r � r F V Cao syy R 'ti"' y � I r � - _ H ��s: a - • .,�': �lb'3Tba p ��; � � �'�'�� y � i §� ' approximately 30-60%. This section vegetation that appears to be regularly should provide good habitat for native maintained. Rodents and seed-eating birds fishes. There is deep water for cover, such as sparrows and finches commonly shallow, fast-water areas for spawning and occur in this habitat due to the abundance feeding, and shade to moderate summer of herbaceous forage and seeds produced 1 water temperatures. by the weedy vegetation. The riparian forest around the two ponded areas Livorna Road to Stone Valley Road upstream of the drop structure provides ( Map V2). overhead cover, creating a high-value Vegetation: The Creek through most of habitat for pond turtles, frogs and ' this section has been modified into a waterbirds. rock-lined channel for flood control purposes, and as a result, has little native Fisheries: The first 300 feet upstream of ' riparian vegetation. The channel is Livorna Road consists of a well-shaded characterized by grass-covered bank slopes (70-80%) pool. The next thousand feet (grassland-ruderal community); trees and ending at the drop structure are an ' shrubs are limited to ornamental unshaded, shallow, partially braided run. landscaping adjacent to the maintenance The substrate is largely fine sediment. The road, Highway 680 and residential next 800 feet is a deep pool, 40-50% backyards. Common trees are non-native shaded. The remainder of the Creek to pine, eucalyptus, redwood, and black Stone Valley Road is a continuous, locust. There are scattered native trees; unshaded pool interrupted only by a drop ' valley and coast live oak seedlings have structure. Except for the two shaded pool established outside the maintenance road. areas, the entire section is poor fish habitat The meander bend, just upstream of the due to lack of cover, few feeding areas and drop structure, has retained its native probable high water temperatures in the vegetation: large-sized valley oaks, summer. buckeyes, and black walnuts form a dense canopied riparian forest. Native shrubs Stone Valley Road to Creek Tree Lane and herbaceous plants, such as California (Maps V2 & V3). rose, poison oak, nightshade, and wild rye Vegetation: This section of the Creek is ' are common in the understory and along predominantly a natural channel that the perimeter of the forest. The invasive, supports dense riparian vegetation; non-native yellow star thistle grows along cottonwood-willow and oak riparian forest the top of the east bank in this area. The inhabit the channel slopes and some freshwater marsh vegetation, growing on top-of-bank areas. Bank modifications the sediment deposits within the channel, is have occurred along the east bank just ' dominated by watercress and various upstream of Stone Valley Road and Alamo grasses. Road and the vegetation is dominated by grassland-ruderal habitat. Tree-of-heaven Wildlife: The wildlife habitat value and black locust, two non-native throughout this section of the Creek is landscape trees have invaded the riparian ' relatively low due to the small amount of corridor along the east bank upstream of riparian forest habitat. The banks are Alamo Road, to the detriment of the native mostly composed of ruderal/grassland tree species. 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The vegetation is comprised of include a large sycamore and several large both cottonwood-willow and oak riparian valley oaks ranging from 40 inches to over forest. There are a few small areas 60 inches in diameter. The ornamental dominated by willow riparian habitat. The landscaping is confined to the top of bank vegetation is dense with native trees, areas just upstream and downstream of including willow, cottonwood, ash, coast.. Alamo Road. live oak, valley oak, English.and black walnut, and big leaf maple. Non-native Wildlife: The riparian forest is narrow pine, almond, black locust, tree-of.heaven, yet continuous, and consists.of large pampas grass, and giant reed are also canopy trees and moderate understory present. Residential construction and vegetation. The forest is likely, to support landscaping have encroached into the moderate wildlife species diversity and riparian corridor.in several areas, thus abundance, as both riparian-obligate bird altering the structure and composition of species and species occurring in urbanized the native flora. Of particular interest are landscapes are predicted to occur. Some the many large-sized native trees; several sections of forest are moderately wide, valley oa.ks., cottonwoods and black thus buffering the effects of adjacent walnuts from 40 inches to over 60 inches human activities and creating more, suitable in diameter were observed during the field micro-climates for riparian-obligates. The reconnaissance. Large stands of the large trees may support raptor nesting, as non-native and invasive giant reed grow open foraging areas occur north of along the banks from Hap Magee Park to Highway 680. The pool upstream from El Portal Road and near La Gonda Court. the drop structure possesses high value for From El Cerro Boulevard to La Gonda amphibians, pond turtles and waterbirds. Way, the riparian corridor has been Riffles may provide habitat for foothill influenced by bank modifications, flood yellow-legged frogs. control activities and encroachment from invasive non-native trees. The vegetation Fisheries: There is a drop structure is relatively sparse along the east bank; approximately 500 feet upstream of Stone however, some replanting of native trees Valley Road. Immediately downstream of and shrubs has occurred. the drop structure is a 50-foot-long riffle created by rip-rap which has fallen into the wildlife: The wildlife habitat value of stream from the bank. From the drop this creek section A similar to that structure, a moderately well-shaded described for Stone Valley Road to Creek (approximately 50%) pool extends Tree Lane except that large native trees are upstream to Creek Tree Lane. This. a significant feature in this section, section should have relatively cool water providing habitat for wildlife such as the during the summer; however, the songbirds who need tree cavities for predominance of pool habitat.limits its nest-building. .Another important value to most native fish species. characteristic is its location adjacent to 35 extensive areas of undeveloped grasslands oak and cottonwood trees that are of north of Highway 680. Widely-ranging botanical significance; many of the trees mammals such as red fox, grey fox and are over 40 inches in diameter. There are coyote may occur more frequently in this scattered locations where the riparian area depending upon the accessibility of corridor has been colonized with invasive .upland foraging areas via minor drainages non-native species such as tree-of-heaven, .that connect with San Ramon Creek. This giant .reed, pampas grass, and black locust. reach is significant due to its potential for. Significant stands occur behind some connection with open space areas. residences off Danville Road, La Gonda Court, near El Cerro Blvd., and near Fisheries: Approximately 700 feet from Diablo Road. Creek Tree Lane there is a 500-foot section of the Creek that is heavily shaded Wildlife: The wildlife habitat.value of (80-90%) and consists of approximately this creek section varies from low to high. 20% riffle habitat, with substrate.ranging The section in the vicinity of El Cerro in size from coarse sand to coarse gravel Boulevard and La Gonda Way.lacks (1/16 - 2 inches in diameter). These riparian forest and is comprised of ruderal fast-water areas are probably used by vegetation; urban species common to native fish for spawning and feedingweedy areas, such as rodents, sparrows, and finches, are predicted to be common The remainder of the.creek consists of here. Turkey vultures roost in the long, moderately deep pools created by eucalyptus trees at the east end of Rose two drop structures DS7 & DS8.• There Avenue. High-value riparian forest occurs are small sections of riffle habitat, rarely downstream of the bare area, in the. more than 20-30.feet long and located vicinity.of La Gonda Court. Here, the . mainly at bridge crossings and immediately riparian forest is wide and is mostly downstream of drop structures. Most of comprised of high-value native trees such this section is,well shaded, with an average as cottonwoods, willows and valley oaks. of approximately 60%. The Creek likely A full compliment of riparian-obligate bird supports both native and introduced,fish species are expected to nest here, including species. There is good quality spawning yellow warbler, Swainson's thrush and habitat for natives and abundant shade and Wilson's warbler. Large native trees moderate summerwater temperatures. provide habitat for a variety of cavity-dwelling wildlife. Access in this La Gonda.way to Diablo Road area is limited, and thus this patch of (Map V4). riparian forest is especially, important to Vegetation: Cottonwood-willow and oak sensitive wildlife including herons and riparian forest are the dominant plant wood ducks. This section represents one communities along this portion of the of the best examples of riparian habitat in Creek and create a densely vegetated the Study Area., corridor. With the exception of some localized bank modifications (e.g., Fisheries: This Creek section begins with immediately upstream and downstream of a drop structure DS8 from which a pool El Cerro Boulevard) the Creek has natural- extends upstream to El Cerro Boulevard. banks. There are several large-sized valley Approximately 500 feet upstream of El 36 Cerro is a 300-foot segment containing and ornamental plantings of eucalyptus and .,several fallen trees and other large pieces black locust dominate the top-of-bank of woody: debris.. Associated scouring and areas. There. are pockets of freshwater deposition has produced a series of pools marsh vegetation along the streambed; and riffles with point bar formation stands of cattail were observed. downstream of the largest debris. This feature provides good fish habitat-however, Wildlife: The wildlife habitat value the area's lack of shade limits its.value to throughout most of this section " similar fish. to that described above for Livorna Road to Stone Valley Road. The modified banks There is one more drop structure, DS9 are mostly composed of ruderal/grassland Other'than short segments of riffle habitat vegetation with'rodents.and seed-eating downstream of this structure and at bridge birds again common because of the crossings, .the entire Creek section consists abundance of herbaceous forage and seeds. of long pools with shade ranging from Pockets of riparian and urban forest trees 0-70% With the exception of the section occur at top-of-bank locations. These trees upstream of El Cerro Blvd., fish habitat is provide nesting habitat. for birds common limited due.of lack of fast-water areas for to urban areas. Although most of this feeding. Creek section supports.pools,:the aquatic P q habitat possesses relatively low waterbird Diablo Road to Sycamore Valley Road and amphibian. habitat due to the general (Maps V4 & Y5). lack of forest and emergent vegetation Vegetation: The Creek channel has been cover around the water margins. The modified for.flood control purposes along sycamores just upstream from Diablo Road . Y J P this section and, a a result, has limited may support roosting herons (as evidenced natural riparian vegetation. Between ` from the observation of one roosting Diablo Road and Highway 680, the east during the field survey).. bank is virtually devoid of riparian vegetation; the,bank slopes-are dominated Fisheries: ..Most of this Creek section by non-native grasses and weeds. Except consists of unshaded, shallow pool habitat. for a large-sized valley oak near Highway. However, for a 1500-footP ortion from .680, the tree composition is limited to Willow Drive upstream to the foot bridge non-native tree-of heaven and pine planted at the end of Laurel Drive, the stream bed along the top of the bank. The west bank ..has been replaced with a concrete "road" has pockets of riparian habitat as evidence with a low-flow channel cut along the east by some remnant large-sized valley oaks, bank. The dropstructure is a 50-foot-lon g sycamores, and black walnuts. Upstream, riffle created by rip-rap which has fallen running parallel to Glen Arms Drive, the into the stream from the bank. From the stream supports a.mixed riparian forest. drop structure, a moderately well-shaded Valley and coast live oaks are the (approximately 50%) pool extends dominant tree species with scattered upstream to S camore Valle Road. Most p Y y occurrences.of California.bay. As one.:. of this section will have high summer moves upstream towards the pe crossing of water temperatures due to the lack of . Sycamore Valley Road, the stream is again shade, thuslimitin its value to fishe g rY channelized. Riparian vegetation is lacking resources. 37 . 1 Syy camore Valle Road to El Capitan however, the occurrence of black locust Drive (Maps Y5 & V6). 0 reduces its overall wildlife value. Vegetation: Most of this.section has Fisheries: This section is typical of the natural, unmodified banks. The vegetation Study Area in that it consists mainly,of is comprised of cottonwood-willow, mixed long pool habitats upstream of drop riparian , and willow riparian forest. structures DS10 chi DS11. There is good There are small pockets of ornamental shade in the section of Creek that borders landscaping near Sycamore Valley Road Osage Park, although the trees are mainly and a grass-lined slope near Osage Park. non-native. The paucity of fast-water In addition to the botanical value of.the areas limits this section as a spawning and native`willows, cottonwoods, valley oaks, feeding habitat for.most native fish and bays of all sizes, there are several species. However, the section is y large-sized trees. The two large well-shaded,_ thus moderating summer. cottonwoods and one valley oak just water temperatures. Native fish' thatp refer downstream of Paraiso Drive are of a slow-water habitat., and some non-native botanical.interest due to their caliper size species,-should do well here. (they are greater than 60 inches in diameter . Also of interest are several El Capitan Drive to Highway 680 ). lar a valley oaks adjacent to Osage Park. (Maps V6 & V7). � y � The mixed riparian g.habitat near Osage , Vegetation: The vegetation resources concentrations of black along this section of the Creek vary from Park has significant locust an invasive non-native tree. This grassland to mixed riparian forest. aggressivegrowth,habits Immediately.upstream of El Capitan Drive species has. such agg that it is a s nficant detriment to the and near .Highway 680 the vegetation is g health andre reduction of the native dominated by grasses and herbaceous p • plants along a modified channel. Cattails, riparian flora. recently mowed when observed in.January,. • cussed for the section inhabit the channel bottom. Near Wildlife:— discussed from Stone Valle Road to Creek Tree Glenbrook Drive and near Camino Ramon, Valley the vegetation becomes a mixed riparianLane, this Creek section supports riparian. forest that is narrow et continuous, and forest. Willows, box elder, buckeye, coast y consists of large canopy trees and moderate live oak, and valley oak create a dense understory vegetation.ve etationLocallythe forest riparian corridor. There are several , is expected high,ted. to su ppo rt moderate to large-sized native trees; of particular , wildlife use due to the revalence of large interest are several large (40 inches and P g • more in diameter willows, valley oaks an native trees. Examples of high-value ) Y riparian are the willow forest just a stand ri of alders. , The top-of-bank areas p downstream of El Capitan Drive and the are composed .of ornamental landscaping p -cottonwood-willow forest at Paraiso including ncluding such trees as pine, redwood, i trees near Osage Park juniper, and acacia. There are scattered Several large native g rovide habitat for cavt dwelling occurrences of invasive non-native plants p y wildlife. The ri arian corridor at Osage within the riparian corridor. These include p Park is moderatelwide, buffering the giant reed, pine, and black locust. y effects of-adjacent human activities; 38