GHAD RESOLUTION NO. 1-2024  AI RESOLUTION APPROVING THE 2ND AMENDMENT OF THE PLAN OF CONTROL FOR THE OAKHURST GEOLOGIC HAZARD ABATEMENT DISTRICT OAKHURST GEOLOGIC HAZARD ABATEMENT DISTRICT  THE BOARD OF DIRECTORS Clayton, California  WHEREAS, by Resolution No. 5-89, the Clayton City Council formed the  Oakhurst Geologic Hazard Abatement District (herein "GHAD"), pursuant to Division 17, Geologic Hazard Abatement Districts, of the Public Resources Code, Section 26500 et  seq.; and  WHEREAS, the Board of Directors of the GHAD approved the Plan of  Control in 1989 and its subsequent 1st Amendment by Resolution No. 2-90 on July 17,  1990; and  WHEREAS, the Plan of Control, prepared under the direction of a licensed  geologist, provides that it will be subject to revisions and modifications, as new data or  investigation warrant; and  WHEREAS, an amendment to the Plan of Control (2nd Amendment)  prepared by BSK Associates has been submitted to the Board of Directors and attached  hereto as Exhibit A; and proposed 2nd amendment.  WHEREAS, the Board of Directors has reviewed and considered said NOW, THEREFORE, BE IT RESOLVED by the Board of Directors of the 1. Amendment No. 2 to the Plan of Control for the Oakhurst GHAD, which is attached hereto as Exhibit A, is hereby approved in its entirety.  GHAD certifies and orders as follows:  2.  The previously approved Plan of Control, including Amendment No. 1, for the Oakhurst GHAD is hereby superseded in its entirety, and shall be PASSED, APPROVED AND ADOPTED by the Board of Directors of the  considered null and void.  GHAD at a regular public meeting thereof held on May 21, 2024, by the following vote:  AYES: NOES:  Directors: Diaz, Tillman, Trupiano, and Wan; Chair Cloven  None.  Resolution No. 1-2024  Page 1of2  May 21, 2024    ABSTAIN: None. ABSENT: None.  THE BOARD OF DIRECTORS OF GHAD  Ce Peter Sloven, Chairperson  Secretary  TE  Ihereby certify that the foregoing resolution was duly and regularly passed by the Board of Directors of the Oakhurst Geologic Hazard Abatement District at a meeting  held on May 21, 2024.  Secretary  d  Resolution No. 1-2024  Page 2 of2  May 21, 2024    EXHIBIT, A  EK  ASSOCIATES  2ND AMENDMED PLAN OF CONTROL  OAKHURST GEOLOGIC HAZARD ABATEMENT DISTRICT  CLAYTON, CALIFORNIA  PREPARED FOR:  OAKHURST GEOLOGIC HAZARD ABATEMENT DISTRICT  CLAYTON, CALIFORNIA  BSK PROJECT NO. G00001941  May 21, 2024  SIONAL s ENGINEERNG  AA46 Richard E.. Johnson, CEG#1452 GEOLOGIST Principal Engineering Geologist OFCALIFO  CITY OF CLAYTON Fandat1837... inarpiraw/196  ENVIRONMENTAL, GEOTECHNICAL, CONSTRUCTION SERVICES AND. ANALYTICAL TESTING    EXHIBIT A 2nd Amended Plan of Control Oakhurst GHAD Clayton, California 1.0 2.0  BSKI Project No. G00001941  May 21, 2024 Pageii  Table of Contents  INTRODUCTION. GEOLOGY. 2.1 Area Geology 2.2 Site Geology. 2.3 Faulting and Seismicity 3.1 Landslide Hazards. 3.2 Soil Creep.. 3.3 Erosion Hazards. 3.4 Expansive Soils.  3.0  GEOLOGIC HAZARDS DESCRIPTION  3.5 Seismically Induced Ground Shaking. 3.6 Liquefaction and Lateral Spreading. 3.7 Faulting Rupture Hazard Zones in California.  4.0  GHAD RESPONSIBILITIES.  4.1 Emergencies  4.2 Preventative Mitigation and Geotechnical Investigations 4.3 Surface and Subsurface Drainage Facilities. 4.4 Creeks and Retention Basins GHAD LIMITATIONS. 5.1 Funding and Risk Limitations.  5.0  5.2 Services Only to Areas Within the GHAD Boundaries 5.3 Geologic Hazard Limited to a Single Property. 5.4 Geologic Hazard Resulting from Negligence of Property Owner. 5.6 Geologic Processes Occurring Entirely in Open Space Areas. 5.8 Damage Due to Seismically Induced Ground Shaking.  5.5 Geologic Hazard which Requires Expenditure Amount Exceeding the Value of the Threatened  or Damaged Improvement. 5.7 Damage Caused by Soil Creep. 5.9 Damage Due to Expansive Soils.  &  5.10 GHAD Funding or Reimbursement for Damaged or Destroyed Structures or Site 5.11 No Reimbursement of Expenses Incurred by Property Owners..  Improvements.  5.12 Appeal to GHAD Board of Directors PRIORITIZATION OF SERVICES. MAINTENANCE ANDI MONITORING SCHEDULE RIGHT OF ENTRY.  6.0 7.0 8.0  EKK    EXHIBIT A 2nd Amended Plan of Control Oakhurst GHAD Clayton, California  BSKI Project  No. G00001941 May2 21,2024 Page lii  Figures  FIGURES  Figure 1- Oakhurst GHAD Boundary Map Figure 2- Area Geology Map Figure 3-L Local Fault Map Figure 4-L Landslide Types  Figure 5-P Potential Liquefaction and tarthquake-iInduced Landslide Hazard Zones  EKK    EXHIBIT. A 2nd Amended Plan of Control Oakhurst GHAD Clayton, California 1.0 INTRODUCTION  BSK Project No. G00001941  May 21,2024 Page 1  Following a petition made by several landowners within the boundaries of the now Oakhurst Geologic Hazards Abatement District, made on December 19, 1988, petitioners asked the City of Clayton toi forma Geologic Hazards Abatement District as provided for in Division 17 of1 the Public Resources Code, Sections 26500, et seq. Per the petition, the City Council for the City of Clayton, in their Resolution No. 5-89, ordered the formation of the Oakhurst Geological Hazards Abatement District (hereinafter the GHAD) on As series of 11 GHAD Resolutions, between December 19, 1989, and July 21, 1998, were passed, each of which annexed additional streets, subdivisions, open space and parcels into the GHAD. Figure 1 presents GHAD Resolution No. 2-90, passed by the GHAD Board of Directors on July 17, 1990, approved Amendment 1 to the Plan of Control for the Oakhurst GHAD. The amendment sought the authority to maintain grading and drainage facilities outside of the boundaries of the GHAD, but within easements As required by Section 26509 of the Public Resources Code, the Plan of Control for the Oakhurst GHAD, superseded by the First Amended Plan of Control, describes potential geologic hazards within the GHAD, properties that have actively been affected byt those hazards sincet thet formation oft the District, and a plan  February 1, 1989.  aE Boundary Map for the Oakhurst GHAD.  created for the maintenance work.  for prevention, mitigation, abatement and/or control.  2.0 GEOLOGY 2.1 Area Geology  The GHAD is located within the northern portion of the Diablo Range, which in turn is located within the Coast Ranges Geomorphic Province of California. The Coast Ranges geomorphic province is characterized by northwest-trendings mountain ranges and valleys that trend subparallel to the San Andreas Fault. The Coast Ranges are composed of thick Mesozoic and Cenozoic sedimentary strata. The northern and The GHAD is located just to the north of Mount Diablo, which forms a prominent feature in the East Bay landscape. Mount Diablo is comprised of three main groups of rocks - Mount Diablo Ophiolite (part of the Coast Range Ophiolite), Franciscan Complex, and Great' Valley Sequence. Ophiolites are thought to form along oceanic spreading centers in the middle of the oceans, associated with oceanic island chains (arcs), or in narrow oceans. Ophiolites generally form a uniform vertical rock sequence consisting, from bottom to top, of ultramafic peridotite from the top of the mantle, mafic intrusive gabbros and/or diabase that formed one or more miles below the sea floor, and mafic extrusive rocks, often in the form of pillow lava The Franciscan Complex records over 140 million years of uninterrupted east-dipping subduction, during which the Franciscan formed as an accretionary complex. As the oceanic plate subducted beneath the continent, part of the uppersection of the ocean crust and the material riding on the plate were scraped off the upper part of the subducting plate, mixed, partially subducted and accreted on and under the  southern ranges are separated by a depression containing the San Francisco Bay.  extruded beneath water.  continental crust.  EKK    EXHIBIT A 2nd Amended Plan of Control Oakhurst GHAD Clayton, California  BSK Project No. G00001941  May 21, 2024 Page 2  The Great Valley Sequence is composed mostly of deepwater marine shale, sandstone, and some conglomerates accumulating to at thickness of 60,0001 feet near the western margin of the Great Valley.  2.2 Site Geology  According to geological maps of the Clayton area (see Figure 2, Area Geology Map), the Town of Clayton is located within an elongated valley surrounded by gently rolling hilly topography. The low-lying portion of Clayton is underlain by Holocene to Pleistocene alluvial deposits consisting of sand, gravel, silt and clay. The majority of the GHAD is located within the hilly topography which is composed of the Great Valley Sequence - interbedded shale, sandstone, and claystone. Some authors have mapped landslides within Onsite surface materials include artificial fill (predominantly engineered fills), landslides, colluvium, and  these units that are within or near the GHAD boundary.  minor sediment erosional deposits from: streams and surface erosion.  2.3 Faulting and Seismicity  The San Francisco Bay Area is seismically dominated by the active San Andreas Fault system. Movement along this fault system is distributed across a complex network of generally strike-slip, right-lateral parallel and sub-parallel faults including, among others, the San Andreas, San Gregorio, Hayward and Calaveras Faults. Although the GHAD is not located within an Alquist-Priolo Earthquake Fault Zone (AP Zone), the mapped trace of the Clayton Fault traverses the GHAD from the southeast to the northwest, as shown on Figure 3, LocalFault Map. The mapped trace of the Clayton Fault does not appear to pass through building footprints, but does potentially impact improvements within the GHAD boundaries. The Clayton Fault is considered an active Holocene fault. An active fault is commonly defined as a fault that has had surface  displacement within Holocene time (the last 11,700 years). The closest AP Zones are associated with thet following faults:  Concord Fault - located approximately 4% miles west from the western GHAD boundary. Greenville Fault - located approximately 14 miles southeast from the southern boundary of the Hayward Fault - located approximately 17 miles southwest from the western GHAD boundary. Except along the mapped fault trace of the Clayton Fault, where the potential for surface fault rupture to occur is considered to be high, we consider the potential for surface fault rupture to occur within most of Because the GHAD is in a seismically active area of California, we expect the area to be subjected to moderate toi intense ground shaking due to a significant seismic event on the active faults int the Bay Area  GHAD.  the GHAD to be low.  and surrounding regions.  3.0 GEOLOGICI HAZARDS DESCRIPTION  Geologic hazards which could potentially affect the GHAD include landslides of all forms, soil creep, erosion, expansive soils, seismically induced ground shaking, liquefaction, lateral spreading, and fault  rupture.  EKk    EXHIBIT A 2nd Amended Plan of Control Oakhurst GHAD Clayton, California 3.1 Landslide Hazards  BSKI Project No. G00001941  May21,2024 Page3  Landslides include a range of mass-wasting processes that, in general, can be described as' "a wide variety of processes that result in the downward and outward movement of slope-forming materials including rock, soil, artificial fill, or a combination oft these" (USGS, 2004*). Landslides are typically differentiated by material type that is involved int thel landslide, the rate of movement, the geometry ofr movement, and the water content. For the GHAD, the most likely forms of landslide that are either present, or could develop  include (see Figure 4 -Landslide Types):  Rotational landslides in artificial fills and colluvial slopes, investigations for the various developments within the GHAD, and Earthflows and Debris flows in native hillside draws and colluvial slopes.  Translational landslides in deep bedrock materials (as identified during preliminary geological  Figure 5s shows areas zoned by the California Geological: Survey (CGS) that have a potential for earthquake-  induced landslides to develop within the GHAD.  3.2 Soil Creep  Creep is defined in the 1st Amended Plan of Control as the slow, gradual, more or less continuous, non- recoverable deformation sustained by soil or rock materials under gravitational body stresses. Creep is distinguished from landsliding by the slow velocity of downhill movement with Creep being limited to a  maximum of three inches of movement per year.  For thep purposes of this Plan of Control, Creep shall not be recognized as a Geologic Hazard.  3.3 Erosion Hazards  Erosion, the mechanical and chemical loosening and downslope transport of soil particles, is generally not, in and of itself, a hazard. As erosion processes continue, though, the formation of rills and gullies does lead to increased potential for surface instability. Erosion and subsequent deposition of sediments can reduce the performance of erosion protection features such as V-ditches. Further, erosion along creek banks can remove toe support for adjacent slopes adding to the potential for larger-scale slope failures.  3.4 Expansive Soils  Near-surface soils including colluvium, artificial fills and some bedrock could exhibit moderate to high potential for shrinkage or swelling with changing moisture content. Alternate shrink and swell can cause heaving and cracking of pavements and structures founded on shallow foundations. Review documents for the original Plan of Control noted that rolechnaircommerditon fort the design and construction of the various developments addressed and, as such, expansive soil hazards were not made a part of the Plan of Control. Therefore, the GHAD does not have responsibility with regard to damage from expansive soils except to the extent that they cause or contribute to slope instability in the opinion of the GHAD General Manager under consultation withi the GHAD's Geological and Geotechnical Engineer of  Record (GGEOR).  1U.S Geological Survey Staff (2004),Types ofl Landslides and Processes: U.S. Geological Survey Fact Sheet 2004-3072  ESK    EXHIBIT A 2nd Amended Plan of Control Oakhurst GHAD Clayton, California  BSK Project No. G00001941  May 21,2024 Page4  3.5 Seismically Induced Ground Shaking  Seismically induced ground motions can be caused by earthquakes on any of the faults surrounding the GHAD. Seismic hazard deaggregation yields the maximum considered earthquake hazard level, distance, and magnitude for each source that contributes to the hazard. Deaggregation of the seismic hazard was performed using the USGS Unified Hazard Tool. In reference to Table 20.3-1 of ASCE 7-16, we consider the general area oft the GHAD as Site Class C( (very dense soila and soft rock). Based on a probabilistic model developed by the USGS (Dynamic: Conterminous U.S. 2014 (updated) (v4.2.0)) and the consideration of the GHAD as Site Class C, deaggregation results indicate that the most extreme seismic source that contributes tot the peak ground acceleration at the GHADist from an earthquake withar moment magnitude The GHAD's responsibility with regard to ground shaking is expected to be limited to response to seismically induced landslides or ground failures that impact public improvements as described in  of M7.19 on the Calaveras Fault at a distance of approximately 10 miles.  Sections 4.0 and 5.01 below.  3.6 Liquefaction and Lateral Spreading  Soil liquefaction is a condition where saturated, granular soils undergo a substantial loss of strength and deformation due to pore pressure increase resulting from cyclic stress application induced by earthquakes. In the process, the soil acquires mobility sufficient to permit both horizontal and vertical movements if the soil mass is not confined. Soils most susceptible to liquefaction are saturated, loose, clean, uniformly graded, and fine-grained sand deposits. If liquetaction occurs, foundations resting on or within the liquefiable layer may undergo settlements and/or a loss of bearing capacity. Figure 5 shows areas zoned by the CGS that have a potential for liquefaction to occur within the GHAD. Lateral spreading is a potential hazard commonly associated with liquefaction where extensional ground cracking and settlement occur as a response to lateral migration of subsurface liquefiable material. These phenomena typically occur adjacent toi freei faces such as slopes and creek channels. Fort the purposes oft this Plan ofControl, liquefaction andI lateral spreading shall not be recognized as Geologic Hazards. At the GHAD General Manager's sole discretion, Services may be provided to address damage resulting from  liquefaction or lateral spreading due to extenuating circumstances. 3.7 Faulting Rupture Hazard Zones in California  The purpose of the Alquist-Priolo Earthquake Fault Zoning Act, as summarized in CGS Special Publication 42 (2018)2, is to "address the hazard of surface fault rupture through the regulation of development in areas near Holocene-active faults and prevent the construction of structures for human occupancy: across traces of active faults." As indicated by Special Publication 42, "the State Geologist (Chief of the California Geological Survey) is required to delineate 'Earthquake Fault Zones (EFZy' along known Holocene-active faults in California. The EFZs are distributed as 'Earthquake Fault Zone maps.' The zones are regulatory in nature and are one class of 'Earthquake Zones of Required Investigation, which includes other geologic hazards such as liquefaction and earthquake-induced landslides. Cities and counties affected by the zones California Geological Survey Staff (2018), Earthquake Fault Zones A Guide for Government Agencies, Property Owners/Developers, and Geoscience Practitioners for Assessing Fault Rupture Hazards in California: California  Geological Survey, Special Publication 42, Revised 2018.  EKK    EXHIBIT A 2nd Amended Plan of Control Oakhurst GHAD Clayton, California  BSK Project No. G00001941  May 21,2024 Page5  must regulate certain development 'projects' within the zones. They must withhold development permits for sites within the zones until geologic investigations demonstrate that the sites are not threatened by As previously discussed, the GHAD is not located within an AP: Zone. The closest Fault-Rupture Hazard Zone is associated with Concord Fault located approximately 4% miles west from the western GHAD boundary. We consider the potential for surface fault rupture to occur within most oft the GHAD to bel low. However, we consider the potential for surface fault rupture to occur along the mapped fault trace of the Clayton Fault (see Figure 3) tol be high. Therefore, for any new development withint the GHAD, structures for human occupancy( (i.e., habitable structures) should not be built along the mapped fault trace oft the Clayton Fault unless specific areas to be developed are cleared of any potentialf fault traces by means of literature review  surface displacement fromf future faulting."  and/or fault trenching investigations. 4.0 GHAD RESPONSIBILITIES  Services authorized under this Plan of Control will focus on the monitoring, maintenance, repair, and mitigation of threatened or actual landslides within the GHADboundaries. Services willf falli into one oftwo 1. Known, existing landslides with known movement at depth and existing drainage facilities. For a. Monitoring and continued maintenance of in-place infrastructure intended to prevent or detect ongoing instability including piezometers, inclinometers, subsurface drainage b. Cleaning, maintaining, replacing and/or installing surface and subsurface drainage 2. Newly discovered or renewed instability that threatens or has damaged infrastructure including roadways, sidewalks, parks, drainage systems, and potentially residential structures. a. Appropriate investigation needed to define the scope of the land movement, as well as  categories:  these landslides, the GHAD willl be responsible for:  facilities, and surface drainage facilities. systems and monitoring instrumentation.  Responsibility of the GHAD include, but may not be limited to: mitigation measures that are appropriate to the situation. b. Site grading/slope reconstruction. Installation of surface and/or subsurface drainage. d. Installation of retaining systems. Installation of debris catchment structures.  For all the above, the GHAD General Manager has sole discretion for prioritizing GHAD expenditures (subject to the guidance provided herein) and for the selection of repair and mitigation methods Property owners within the GHAD boundaries should contact the GHAD management to either report a new geologic hazard incident or condition on their property or adjacent public works facilities. When contacted, the GHAD General Manager shall respond to the inquiry and indicate whether the incident or inquiry falls within the responsibilities of the GHAD, and if sO, what steps may be taken to address the  appropriate to a particular situation, within the constraints described herein.  incident.  EKK    EXHIBIT A 2nd Amended Plan of Control Oakhurst GHAD Clayton, California  BSK Project No. G00001941  May 21, 2024 Page6  The GHAD is authorized to act to prevent, mitigate, abate or control geologic hazards, hereinafter referred  toas "Services", in the following situations:  4.1 Emergencies  During emergency situations when a landslide presents an active or imminent threat to improved property, the GHAD may implement interim slope stabilization measures that can arrest or minimize further slope movement until long-term mitigation measures can be implemented. Interim slope stabilization measures can include, but are not limited to, thei temporary installation of slope coverings or drainage infrastructure to prevent further water infiltration or erosion, installation of structural elements to prevent or arrest motion of a landslide, or grading to remove or buttress unstable slopes. Emergency preparation measures may also be takeni ina advance of threatening landslides; these measures mayi include stockpiling slope stabilization materials and/or having resources in-place ready to respond rapidly.  4.2 Preventative Mitigation and Geotechnical Investigations  The GHAD may provide Services for landslides that threaten improved property using a number of mitigation techniques. The selection of mitigation techniques depends on the type and rate of failure of landsliding, equipment accessibility, urgency, and other factors. Prevention of landslides can sometimes be achieved using surface and: subsurface drains. Imminent landslides can potentially be stabilized by one ora combination of, but not limited to, 1). The construction of retaining structures, 2). Slope stich piers or soil nail anchors extending beyond the slide plane, 3). Dewatering facilities, or 4). Toe buttresses, to name at few. Landslide-damaged slopes can be reconstructed and stabilized by removal of landslide debris and rebuilding the slopes with properly compacted and drained, engineered fill. These or other appropriate techniques should be selected based on the actual site conditions and available funding. The GHAD General Manager in consultation with the GHAD's GEOR will make the final decision in determining the At the GHAD General Manager's sole discretion, a geotechnical investigation may be conducted for areas where unstable conditions or landslides exist or are believed to exist. The purposes of the geotechnical investigation are to evaluate the cause of the unstable slope conditions and to identify and define repair or stabilization options. Geotechnical monitoring, whether short-term as part of an active landslide investigation, or long-term, to track changes in groundwater levels and/or surface and subsurface movement, are authorized activities of the GHAD as related to the prevention, mitigation, abatement, or  type of action that best fits the need of each GHAD project.  control of landslides within the GHAD's boundaries. 4.3 Surface and Subsurface Drainage Facilities  The GHAD may maintain, repair and/or replace those portions ofs surface ands subsurface drainage facilities including, but not limited to, concrete V-ditches, storm sewer lateral pipes, catch basins, horizontal drains, subdrain pipes, subdrain pipe inlets and outlets when they are directly related to the repair, prevention, or control of landslides. Maintenance includes removal of sediment from ditches and hydro-cleaning of  horizontal drains and subdrains. 4.4 Creeks and Retention Basins  As part of its duties to mitigate against actual or threatened landslides, the GHAD may perform the  following GHAD: Services in creek channels and retention basins:  EKK    EXHIBIT A 2nd Amended Plan of Control Oakhurst GHAD Clayton, California  BSK Project No. G00001941  May 21,2024 Page7  Clearing and removal of debris and/or impediments in creek channels under emergency conditions to maintain open stream flow in order to mitigate creek bank erosion. Removal of significant quantities of sediment and/or debris deposits in retention basins to Reconstruct retention basin berms and standpipes as needed to maintain functionality.  maintain functionality. 5.0 GHAD LIMITATIONS  When considering whether to proceed with Services in response to a geologic hazard, the GHAD is  authorized to take into consideration the following limitations and exclusions:  5.1 Funding and Risk Limitations  The GHAD Board of Directors is required to approve or not approve authorized Services based oni funding limitations followed by project priorities based on risk evaluation and priorities as established in Section 6.0 below. If revenue is not sufficient, due to the failure of property owners to approve a rate increase as presented to them by the GHAD, the GHAD would be required to reduce, postpone, and/or eliminate some or all GHAD Services unless an alternative funding can be identified. This means that the GHAD may be limited in its ability to maintain, monitor, mitigate, or respond to geologic hazards due to lack of funding. Failure to provide adequate funding to the GHAD does not render the GHAD nor the City In the event of insufficient funding to perform all of the recommendeu/required maintenance and monitoring within this Plan of Control due to the failure of property owners to approve a rate increase as presented to them by the GHAD, then the GHAD Board of Directors will request the GHAD General Manager to annually present a prioritized list of activities within the available budget. This means that each parcel will be at increased risk of landslide hazard, which the owner of the parcel, and not the GHAD, will be responsible for mitigating. The GHAD will annually notify the assessed property owners that the assessments currently collected is insufficient to perform the recommended/requred maintenance and monitoring of the underlying land of the Oakhurst  responsible or liable for any harm or damage caused bya a geologic hazard.  development which will lead to an increased risk of landslide hazards. 5.2 Services Only to Areas Within the GHAD Boundaries  The authority to provide Services is limited to those properties located within the GHAD boundaries, and tosome degree, to offsite drainage facilities that could impact property within the GHAD boundaries. The GHAD can provide Services for a geologic hazard on property outside the GHAD boundaries when the hazard has damaged or poses an imminent threat of damage to structures or site improvements located on properties within the GHAD boundaries. Should the GHAD be required to respond to a geologic hazard outside the boundaries of the GHAD, the GHAD mayt take such actions as may be appropriate to recover costs incurred as a result of preventing, mitigating, abating or controlling such geologic hazard from the  responsible party, ifany.  5.3 Geologic Hazard Limited to a Single Property  The GHAD will not provide its Services for landslides that are contained within the limits ofa single parcel of property. Hazards must extend across or into open space and/or at least two residential property boundaries within the GHAD before the GHAD will implement the Plan of Control as described herein. At the GHAD General Manager's sole discretion, Services may be provided to address a geologic hazard within a single  property due to extenuating circumstances.  EKK    EXHIBIT A 2nd Amended Plan of Control Oakhurst GHAD Clayton, California  BSKI Project No. G00001941  May 21, 2024 Page8  5.4 Geologic Hazard Resulting from Negligence of Property Owner  The GHAD may decline to provide Services for geologic hazards that occur due to, or result from, the negligence of the property owner and/or the property owner's contractors, agents or employees in developing, grading, constructing, maintaining, performing, or not performing, any work related to, or that may have influenced the geologic hazard on the subject property, including performing alterations tos site drainage or slope configuration that adversely impact the overall existing stability of slopes. If the GHAD bears expense as the result of negligence described in this section, the GHAD may pursue 5.5 Geologic Hazard which Requires Expenditure Amount Exceeding the Value of the The GHAD may elect to not provide Services where, in the GHAD General Manager's sole discretion, the anticipated expenditure required to be funded by the GHAD will exceed the value of the structure(s)  reimbursement from the negligent parties.  Threatened or Damaged Improvement  and/or site improvement/s) that are threatened with damage or loss. 5.6 Geologic Processes Occurring Entirely in Open Space Areas  The GHAD will not provide its Services for landslides, creek bed erosion or deposition, etc. that occur entirely in open space areas. In the GHAD General Manager's sole discretion, geohazard impacts from open space lands that impact roadways, sidewalks, or otheri improvements deemed relevant byt the GHAD  General Manager, may receive Services. 5.7 Damage Caused by Soil Creep  The GHAD will not provide Services for damage due to soil creep. Site-specific design and construction techniques can typically be implemented by property owners to reduce the impact of creep on their  properties.  5.8 Damage Due to Seismically Induced Ground Shaking  The GHAD will noti fund Services or otherwise compensate for damage resulting from seismically induced 1. Damage to public infrastructure within the GHAD boundaries, as authorized by the GHAD General 2. Damage resulting from seismically induced landslides, as authorized by the GHAD General Manager and subject to the availability of funds and the other restrictions included within this  ground shaking except for the following:  Manager and subject to the availability of funds.  Plan of Control.  5.9 Damage Due to Expansive Soils  The GHAD will not fund Services or otherwise compensate for damage due to expansive soils except for 1. Damage to public infrastructure within the GHAD boundaries, as authorized by the GHAD General  thei following:  Manager and subject to the availability of funds.  EKK    EXHIBIT A 2nd Amended Plan of Control Oakhurst GHAD Clayton, California  BSK Project No. G00001941  May 21,2024 Page9  2. Damage resulting from landslides where the presence of expansive soils may be a contributing factor to the landslide and as authorized by the GHAD General Manager and subject to the availability offunds and the other restrictions included within this Plan of Control. 5.10 GHAD Funding or Reimbursement for Damaged or Destroyed Structures or Site  Improvements  Except as limited by Sections 5.3 and 5.5 above, int the event a habitable structure, site improvement, or landscaping is damaged or destroyed as a result of a geologic hazard, the GHAD may elect to fund or reimburse the property owner for the reasonable expenses necessary to repair or replace the damaged or destroyed structure, site improvement, or landscaping. Unless otherwise authorized by the GHAD Board of Directors, the dollar amount of the GHAD1 funding or reimbursement may not exceedi ten percent (10%) of the costs incurred by the GHAD in preventing, mitigating, abating or controlling the geologic hazard responsible for the damage. The GHAD may decline to provide any funding, or reimbursement to ap property owner for the repair or replacement ofa a structure, sitei improvement, or landscaping damaged by a geologic hazard where at its construction or installation, the structure, site improvement, or landscaping violated any provision of the City's building code or ordinances that was operative when the  structure, site improvement, or landscaping was constructed. 5.11 No Reimbursement of Expenses Incurred by Property Owners  The GHAD will not be obligated to reimburse a property owner for expenses incurred fort the prevention, mitigation, abatement, or control ofag geologic hazard absent a written agreement between the property owner and the GHAD to that effect, which agreement has been executed prior to the property owner  incurring said expenses, and following an investigation conducted by the GHAD.  5.12 Appeal to GHAD Board of Directors  Any determination made by the GHAD General Manager in its sole discretion may be appealed to the GHAD Board of Directors through a written letter ofa appeal submitted within 10 days oft the GHAD General  Manager's written determination to the affected party. 6.0 PRIORITIZATION OF SERVICES  Emergency response and scheduled repair, maintenance and monitoring expenditures are to be prioritized at the discretion of the GHAD General Manager, based on available funds (including reserve funds), and pursuant to paragraph II of the DISTRICT OBLIGATIONS AND REVENUE  GENERATION, Statement of Policy (Approved May 5, 1998), amended as follows:  "In order to make the best of available funds, a priority of expenditures has been established as  follows: a) b) c)  first, resources shall be used to secure public safety;  second, resources shall be used to secure the safety of public and private third, resources. shall be used for the cleanup and repair of public propertyto  property;  minimum standards of publics safety;  EKK    EXHIBIT A 2nd Amended Plan of Control Oakhurst GHAD Clayton, California  BSK Project No. G00001941  May 21, 2024 Page 10  d) f)  fourth, resources shall be used for the repair of public property to like new e) fifth, resources shall be used fort the cleanup and repair of private propertytoa sixth, resources shall be used for increasing the District'sreserves to levels  condition;  level determined by the GHAD Board of Directors; determined by the GHAD Board of Directors.  Consistent with priorities a and b, above, and in the absence of active construction for remediation of geologic hazards' impact to public and private property, expenditures shall be prioritized as follows (in 1) The prevention, mitigation, abatement or control of geologic hazards that have damaged or pose as significant threat of damage to underground water and sewer infrastructure, paved streets, 2) The prevention, mitigation, abatement or control of geologic hazards that have damaged or pose as significant threat of damage to private recreation facilities (such as pools, pool cabanas, sport 3) The prevention, mitigation, abatement or control of geologic hazards that have damaged or pose asignificant threat of damage to landscaping and other non-essential amenities.  descending order of priority):  habitable structures, and other critical underground utilities.  courts, or the like).  7.0 MAINTENANCE AND MONITORING SCHEDULE  Geologicfeatures, GHAD maintainedi facilities, and: surface pavements withing the public right-of way (and particularly within known landslide areas) shall be inspected and monitoring facilities, including piezometers and inclinometers, shall be sounded and recorded at proper intervals. Inspections and monitoring should be increased in frequency during years with abnormally high frequency or high Ing general, all V-ditches, drop inlets, debris basin standpipes, subdrain clean-outs and outfall/discharge The GHAD General Manager shall review and adjust the inspection and monitoring schedule annually and, based on the annual report from the GHAD's GGEOR, assess the effectiveness of its preventive maintenance program on a regular basis. The GHAD Generall Manager shall prepare an annualinspection  intensity rainfall events.  pipes should be observed during each inspection event.  report for presentation to the GHADI Board of Directors.  The table below presents the inspection and monitoring schedule for the GHAD:  EK    EXHIBIT A 2ndA Amended Plan of Control Oakhurst GHAD Clayton, California  BSK Project No. G00001941  May 21, 2024 Page 11  Elements of 2nd Amended Plan of Control District bigationReponsblites Administration Geologist Site Assessment Report Annual Maintenance Activities Debris removal Vegetation Management Periodic Maintenance Activities Subdrain clearing Monitoring Activities Drainage Ditches  Service Description  Frequency Continuous  Preparation and presentation of annual inspection and maintenance report by the GHAD management based on report(s) andi memoranda  prepared by the GGEOR Clear V-Ditches and inlets  Frequency Annually in December  Frequency Annually in the Falla and at other times during heavy rainfall years  Weed abatement in open spaces per fire code  Frequency Annually in the Summer  Root or jet subdrains and outfall pipes ifr reduced flow is observed (relative to other drains or prior observations).  Frequency As-needed  Visual inspection of lined surface drainage V-ditches by GGEOR within hillside residential areas of the GHAD and immediately adjacent open space. Delverable/ensaxement: Letter summarizing observations. yearly (in the Fall andi in the Winter) during heavy rainfall years Visual inspection of risers and outlets to storm drains from debris Field locate and determine inclinometer and piezometer ID from previous studies. Differentiate, if possible, dual-purpose incinomete/Plezometer, Deliverable: memorandum and site plan.  Frequency Atl least one yearly (int the Fall before rain season starts) or at least twice  Risers and outlets  barriers.  Frequency Annually in the Fall  Existing slope Inclinometers and piezometers- Locate and Identify  Frequency One time As soon as possible Frequency One time As soon as possible  Locate subdrainage clean-outs and Fieldi locate. Deliverable: memorandum and site plan.  subdrain outfalls Delineators/Markers  Check delineators/markers are present at all outlets of subsurface drains, all piezometers, all inclinometers, and all de-watering wells- Visual inspection of outlets of all subsurface drain outlets, measure  replace as needed Ongoing Monitoring" inspections flowrate. Deliverable: memorandum. EK  Frequency Included w/ "Subsurface Drain Discharge" and' "Slope inclinometers  Subsurface Drain Discharge  Frequency At least twice yearly (Fall and Spring)    EXHIBIT A 2nd Amended Plan of Control Oakhurst GHAD Clayton, California  BSK Project No. G00001941  May 21, 2024 Page 12  Elements of 2nd Amended Plan of Control Slope Inclinometers Ongoing Monitoring Piezometers  Service Description  For select inclinometers, measure inclinometer offsets across the entire casing. Measure depth to groundwater for dual purpose incinometer/pezometer, Deliverable: memorandum.  Frequency Early Fall, mid-Winter, andl late Spring Frequency Early Fall, mid-Winter, and late Spring  Measure groundwater level in piezometers (if done separately of "Slope Inclinometers Ongoing Monitoring" inspections). Deliverable: Visual inspection of roadways, sidewalks, and facilities (if done separately of "Drainage Ditches" inspections) within hillside residential areas of the GHAD and immediately adjacent open space. Deliverable:  memorandum.  Open and Public Space Land  memorandum.  Frequency Annually ini the Spring Frequency As-needed Frequency As-needed Frequency As-needed Frequency As soon as possible  Minor Repairs Debris Basins V-Ditches  Restore debris basins to pre-mudslide elevations Repair cracks/gaps in drainage ditches. Replace significantly distressed/damaged drainage ditch panels. Repair/Replace risers, pipes, and outlets  Drainage pipes/risers Inclinometer Replacements  Replace 2 sheared inclinometer casings One at Kelok Way and one at Pebble Beach Drive Landslide area. Deliverable: two new inclinometers.  Infrastructure Renewal V-Ditches Drainage pipes/risers Inlets/Manholes Access Road Surfaces  Replace facilities at the end of service life Replace facilities at the end of service life Replace facilities at the end of service life Replace facilities ate end ofs services life  Frequency As determined by the GHAD General Manager Frequency As determined by the GHAD General Manager Frequency As determined by the GHAD General Manager Frequency As determined by the GHAD General Manager  EKK    EXHIBIT A 2nd Amended Plan of Control Oakhurst GHAD Clayton, California  BSKI Project No. G00001941  May 21, 2024 Page 13  8.0 RIGHT OF ENTRY  GHAD officers, employees, consultants, contractors, agents, and representatives shall have the right to enter upon all lands within the GHAD boundary for the purpose of performing the activities described in this Plan of Control. Such activities include, but are not limited to, 1). the inspection, maintenance and monitoring of site improvements including, drainage ditches, storm drains, outfalls and pipelines, 2). the monitoring, maintenance and repair of slopes, including repaired or partially repaired landslides, and 3). the management of erosion and geologic hazards within open space. Should the GHAD need to access private residential lots to fulfill its duties under the Plan of Control, the GHAD shall provide the affected property owner with 72 hours advanced notice unless, in the reasonable judgment of the GHAD General Manager, an emergency situation exists which makes immediate access necessary to protect the public health and safety, in which case no advanced notice is required, but the GHAD shall inform the property  owner as soon as reasonably possible.  EKK    EXHIBIT A 2nd Amended Plan of Control Oakhurst GHAD Clayton, California  BSKI Project No. G00001941  May 21, 2024  FIGURES  EKK    DI    EXHIBITA  Env  Kb  Ed  pf Qhty  Ka  Env  Approximate Scale Nott to Scale  0 Kcu  Pemzu Kcus Pemzl  08 S  Fel  Qht  3-Kcu Kd  Qpay  Qof - Qof Qht Qht Qpa  Kcus  Qhc  Kcu  QPu  QpfL  Qhc Qht Qpf  Tangalide! Kb  Qof Qpa  Qof af  - oM  References: 1.California Clayton 7.5-Minute Geological Quadrangle, Survey Staff Contra (2021), Costa Seismick County, Hazardz Califomia: Zone Reportf Califomia forthe af- Artificial Fill (Historical)  Geological Survey, Seismic Hazard2 Zone Report 130.  Qhty- Stream Terrace Deposits (Latest Holocene) Qhc Stream Channel Deposits (Holocene) Qha -/ Alluvium, Undifferentiated (Holocene) Qhf-Alluvial Fan Deposits (Holocene) Qht- Stream Terrace Deposits (Holocene) Qpf- Alluvial Fan Deposits (Latest Pleistocene) Qpa / Alluvium, Undifferentiated (Latest Pleistocene) Qof-Alluvial Fan Deposits (Pleistocene) Qoa A Alluvium, Undifferentiated (Pleistocene) Env- Nortonville Shale (Tertiary) Ed- Domengine Formation (Eocene) Pemzw/Pemzi Meganos Formation (Paleocene) Great Valley Sequence: Kcu- Shale and Siltstone (Late Cretaceous) Kcus - Sandstone (Late Cretaceous) Kb-S Sandstone and Shale (Early/Late Cretaceous) Ka-s Shale (Late and Early Cretaceous)  Approximate GHAD boundary (see Figure 1 for actual GHAD boundary)  PROJECT NO. G00001941 DRAWN: 02/01/24 DRAWN BY: D.J Tower CHECKED BY: O.Khan FILE NAME: Figures.indd  AREA GEOLOGY MAP Oakhurst GHAD Plan of Control Oakhurst GHAD Clayton, California  FIGURE 2  EKK ASSOCIATES    Approximate Scale Not to Scale  References: 1.USGS Interactive Quaternary Fault Map (https:!! usgs.maps. arcgis. X 3a1684561a' 9b0aadf884121c)  Latest Quaternary (<15,000 years), well constrained location Latest Quaternary (<15,000 years), moderately constrained location Latest Quaternary (<15,000 years), inferred location Approximate GHAD boundary (see Figure 1 for actual GHAD boundary)  sources  FIGURE 3  PROJECT NO. G00001941 DRAWN: 02/01/24 DRAWN BY: D.1 Tower CHECKED BY: O.Khan FILE NAME:  LOCALFAULTMAP Oakhurst GHAD Plan of Control Oakhurst California GHAD Clayton,  Esk ASSOCIATES  Figures.indd    EXHIBITA  A  Surfacerupture  Rotational landslide  Translational landslide  Block slide  D  E  F  6747  Rockfall  Topple Sourcearez  Debris flow Curvedmeetrunks  G  H  s Earthflow  35  2  Fenceoutofaligmment  Debris avalanche  Creep  Lateral spread  References: 1.U.S. Geological Survey Staff (2004), Types ofLanslides and Processes: U.S. Geological Survey, Facts Sheet2 2004-3072  PROJECT NO. G00001941 DRAWN: 02/01/24 DRAWN BY: D. Tower CHECKED BY: O. Khan FILE NAME: Figures.indd  LANDSLIDE TYPES Oakhurst GHAD Plan of Control Oakhurst GHAD Clayton, California  FIGURE 4  EKK ASSOCIATES    IBIT  Approximate Scale Not to Scale  Reference: Califoria Geological Surveys Staff (2021), Earthquake Zones ofRequiredl Investigation, Clayton Quadrangle: Call- fornia Geological Survey, Earthquake Faultz Zones and Seismich Hazardz Zones, Released September: 23, 2021.  SEISMIC HAZARD: ZONES  Approximate GHAD boundary (see Figure 1 for actual GHAD boundary)  Liquefaction Zones Areas where! historical occurrence ofliquefaction, orl localg geological, geotechnical andg ground water conditions indicate potentialf for permanent groundd displacements sucht thatr mitigationa as definedi inPublic Resources Code Section 2693(c) would ber required. Earthquake-inducedi Landslide Zones Areas wherep previous topographic, geological, geotechnical: ands subsurfacev water conditions indicate aj potential for permanent groundo displacements sucht thatr mitigation asd definedi inF Public Resources Code Section 2693(c) wouldber required.  oflandslider movement, orl local  PROJECT NO. G00001941 POTENTIALLIQUEFACTION AND FIGURE  EARTHQUAKENDVCED LANDSLIDE HAZARD ZONES Oakhurst GHADI Plan of Control Oakhurst GHAD Clayton, California  DRAWN: 02/01/24 DRAWN BY: D.1 Tower CHECKED BY: O.Khan FILE NAME:  5  EKK ASSOCIATES  Figures.indd