Introduction

INTRODUCTION

This document responds to issues raised by Sarah H. Sigman of the law firm of Shute, Mihaly & Weinberger LLP, in a letter to the Town of Los Altos Hills dated January 20, 2016 regarding the “Stirling Subdivision Mitigated Negative Declaration” (“Shute Letter”). The Shute Letter was submitted on behalf of the Friends of Upper Matadero Creek whose members are not identified in the letter. The environmental document to which the Shute Letter refers is the Initial Study/Mitigated Negative Declaration for the Stirling Subdivision (EMC Planning Group, September 2015) (“IS/MND” or “IS”), which was prepared for the Town of Los Altos Hills as the lead agency. The responses included in this letter are organized and numbered to correspond to those included in the Shute Letter.

This document also responds to issues raised by Sue Welch, whose comments are included in a letter dated January 22, 2016 regarding 28030 Natoma Road (“Welch Letter”)

Both letters were submitted after the close of the 30-day public review period for the IS/MND. The letters are included as Attachments A and B, respectively.

This document contains information that supplements and refines analysis and mitigation measures already included in the IS/MND pursuant to issues raised in the above-referenced comment letters.

II.A Footbridge Description

The commenter states that the IS/MND’s description of the footbridge across the Matadero Creek is not described with sufficient detail to allow an informed analysis of its impacts under CEQA. CEQA Guidelines Section 15146, Degree of Specificity, notes that the degree of specificity required in an Environmental Impact Report (“EIR”) will correspond to the degree of specificity involved in the underlying activity which is described in the EIR. CEQA Guidelines Section 15071, Contents, states that a Negative Declaration shall include a brief description of the project. At the time the IS/MND was prepared, detailed information about the pedestrian footbridge design was not available. Consequently, information included in the project description about the footbridge was brief, but sufficient to allow an informed analysis of its potential impacts. Sheet 3 of the Tentative Map included in Attachment C of the IS/MND identified the approximate location of the proposed footbridge. Furthermore, as part of the project description, the planned footbridge is shown across Matadero Creek (p. 14). Since publication of the IS/MND, additional detail has been provided about the footbridge (described below), however this supplemental information does not change the analysis, mitigations, or conclusions in the IS/MND. The potential impacts of constructing the footbridge are identified throughout the IS/MND, including potential impacts on biological resources and water quality as described below. Thus, there is no basis for the commenter to conclude that the analysis of the footbridge’s impacts is inadequate under CEQA.

Level of Detail. CEQA requires an MND to include the location of the project, preferably shown on a map, the proposed findings, a copy of the IS/MND documenting the reasons supporting the findings, and mitigation measures, if any, included in the project to avoid potentially significant effects. The location of the proposed footbridge and its approximate size are identified and disclosed to the public in the IS/MND. Furthermore, the potential impacts of constructing the

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footbridge over Matadero Creek to riparian habitat and wildlife are adequately anticipated and described in the IS/MND. Construction and operational impacts on Matadero Creek (a jurisdictional waterway) and on riparian habitat were conservatively assumed to be potentially significant as described in the IS/MND (p. 51). Mitigation measure BIO-7 is included in order to mitigate the potential impacts to less than significant. Mitigation measure BIO-7 describes bridge design conditions that would trigger significant impacts and includes specific performance standards that must be met to reduce the impacts to less than significant. The IS/MND thus adequately describes the size and location of the footbridge and proposes mitigation to avoid any potentially significant impacts.

Water Quality Impacts. Water quality in Matadero Creek could be adversely affected by footbridge construction activities if erosion control and other water quality protection measures are not taken. As described in the IS/MND (pp. 68-70), all construction activities within the site would be regulated through the National Pollutant Discharge Elimination System (“NPDES”) requirements of the California Water Quality Control Board. Best management practices (which could include timing of construction, erosion protection and sediment control, solid waste management, etc.) must be employed during bridge construction to protect water quality, and will be defined in a Storm Water Pollution Prevention Plan (“SWPPP”). The adequacy of the Storm Water Pollution Prevention Plan will be evaluated by the Town Engineer subject to consistency with defined regulatory performance standards. This issue is discussed in more detail in the discussion of water quality issues in Section IV.C.2 below. Best management practices to protect water quality during construction of the footbridge, as well as the entire project, must be employed regardless of the detailed bridge design.

Wildlife Impacts. The IS/MND also discloses the effects of the proposed project on special- status wildlife (pp. 41-50). As stated at the bottom of page 41, “If present within proposed impact areas on the site (including the pedestrian bridge and recreational trail within the wooded open space easement area), development may impact the above species.” Mitigation measures BIO-2, BIO-3, BIO-4, BIO-5, BIO-6, and BIO-7 proceed to address potential impacts of constructing the proposed project, including the footbridge, on the nine special-status wildlife species with potential to occur within the site, including Matadero Creek and its associated riparian habitat. The mitigation measures contain performance standards that must be met regardless of the final detailed bridge design, which is all that CEQA requires.

Additional analysis of the potential impacts of the footbridge on wildlife movement and wildlife has been conducted by Live Oak Associates in a letter dated April 21, 2016, and in a letter prepared by H.T. Harvey & Associates dated April 28, 2016. The letters were prepared to clarify and refine analyses in the IS/MND. The letters are included as Attachments D and E. Live Oak Associates concludes that the proposed trail along the northern boundary of the site and the bridge design (perpendicular crossing of creeks with a free-span bridge is preferred by resource agencies) will not substantially impede movement patterns of any wildlife. Live Oak also notes that during construction of the trail and bridge, daytime wildlife movements may be temporarily altered, but movements during dawn and twilight (crepuscular movements), and nighttime movements will not be appreciably affected. Once the 4 to 12 week construction period for these improvements ends, regional movement patterns are expected to return to pre-construction conditions. Live Oak Associates concludes that the temporary effects on daytime movements would be less than significant (Live Oak Associates 2016, p. 3).

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H.T. Harvey draws conclusions that are similar to Live Oak Associates. H.T. Harvey does not expect the construction of a footpath on the northern portion of the project site or a footbridge across Matadero Creek to substantially interfere with wildlife movement along the Matadero Creek corridor. H.T. Harvey observed numerous trails paralleling the creek within the future open space area such that animals will not be restricted to moving through the open space area at any one location (e.g., the location of the proposed footbridge). Neither the path nor bridge will include features such as tall, impassable fencing that would preclude the ability of a variety of animals to simply walk across the path or under or around the bridge. Furthermore, because many of the reptiles, amphibians, and mammals that may move within or through the project site along the Matadero Creek corridor are active at night when little or no human use of the path or bridge is expected, human activity along the path and bridge will not substantially interfere with the ability of wildlife to cross the trail (H.T. Harvey & Associates 2016, p. 3). No evidence, much less substantial evidence, has been provided to support a fair argument that the proposed pathway and footbridge, as mitigated, would have a significant impact on the environment.

Additional Footbridge Description Information. Prior availability of a refined footbridge design or construction plan would not have materially affected the conclusions in the IS/MND regarding its potential impacts. Regardless, the applicant has now provided supplemental design and construction methodology details for informational purposes.

The location of the footbridge is now defined. Its location has been established based on the results of a Creek and Riparian Jurisdictional Assessment conducted by WRA in April 2016. The jurisdictional assessment is included as Attachment F. The field surveys consisted of multiple site visits to determine the location of the Ordinary High Water and the California Department of Fish and Wildlife (“CDFW”) jurisdictions of the creek as required in mitigation measure BIO-7 in the IS/MND. The purpose was threefold: 1) to locate the bridge outside of any portion of the creek that could be considered jurisdictional by the United States Army Corps of Engineers (USACE); 2) to avoid removal of riparian vegetation; and 3) to identify the narrowest reach of the creek in the immediate vicinity of the preliminary bridge location shown on the Tentative Map at which the bridge abutments can be installed above the bed or bank of the creek. For the proposed location, an approximately 35-foot long bridge measured as the distance between the bridge abutments would be required. The bridge would be approximately five feet wide.

Regarding construction, exact scheduling and details will be determined with a qualified contractor when the contractor is retained. However, the preliminary construction and materials approach can be summarized as follows:

. Light weight construction materials will be selected during the detailed design phase. There is an abundance of light-weight material choices for the footbridge. The footbridge abutments will be constructed using concrete and backbone support will consist of three steel beams.

. There will be two construction access points, one from the project site and one from the opposite side of the creek. From the project site, construction materials will be hand carried down the hill from the upland portion of the project site where subdivision improvements are proposed. From across the creek, access will be via Edgerton Road, using the paved Fire District access road, which is also a Pathway Easement. This access road connects to the

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Stegner Trail within approximately 150 feet of the intersection of the Stegner Trail and the new trail planned as part of the proposed project.

. To adjust for the narrow and sensitive access routes to the footbridge site, equipment for constructing the footbridge will largely be limited to hand tools, small trucks, and simple excavation equipment such as backhoes and Bobcat loaders. Any vehicles and light equipment will utilize the Fire District access road.

. The abutment excavations will most likely be dug with hand tools. Concrete for the abutments will be mixed at the abutment sites to avoid the need for large concrete transport vehicles to access the footbridge location. Approximately 250 gallons of water are needed to mix the concrete. This volume can be accommodated with a tank on a one-ton pickup truck.

. A temporary cable pulley system will be constructed between the two bridge abutments so that the bridge beams and other materials can be transported across the creek. This is a commonly used bridge construction mechanism that is used to limit the need to cross the creek and minimize the construction zone footprint.

II.B Additional Activities within Open Space Easement

The commenter also states that the IS/MND does not adequately describe information about additional project activities occurring within the proposed Open Space Easement. The analysis in the IS/MND explains that regulatory standards and mitigations identified in the IS/MND would ensure that potential impacts from construction/operation of these features on special-status species plant and wildlife, water quality, and cultural resources will be less than significant. Nonetheless, a more detailed overview of these improvements is provided below in order to amplify and clarify the IS/MND’s discussion.

Stormwater Drainage Pipe and Energy Dissipator. As described in the IS/MND (pp. 68-70), the proposed project is subject to C.3 stormwater control requirements. Stormwater control measures must be included in the proposed project to ensure its consistency with Santa Clara County’s broader NPDES Permit No. CAS029718. Sheet 7 of the Tentative Map included in Appendix A of the IS/MND show stormwater control and stormwater quality design features included in the project.

As required by current storm water regulations, the storm water runoff from the subdivision will be treated to maintain water quality using multiple features, including a bio-filtration pond. After treatment (natural filtering), the runoff will be conveyed through an underground detention tank designed to limit the rate of peak runoff from the site to the pre-development peak rate. These features are shown on the Tentative Map and are located above the boundary of the open space easement.

Two additional storm drainage improvements that are part of the proposed project were inadvertently omitted from the project description. These include a storm drainage conveyance pipe and a storm water energy dissipator. The flow from the detention tank will be conveyed downhill through the open space easement in a 15-inch diameter pipe. The pipe will be installed underground within a trench from the detention tank location to the uphill (eastern) boundary of the open space easement. To minimize the disturbance of tree roots the pipe will “daylight” out

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of the ground at the easterly edge of the open space easement. The segment within the open space easement will be only partially buried. The pipe will be staked to the ground surface using a standard pipe installation technique for a “downdrain pipe”. A semicircular groove will be excavated in the slope using hand tools to embed the lower half of the pipe into the soil, leaving approximately eight to nine inches of pipe above ground. This technique will minimize trenching and disturbance to tree roots, while reducing the profile height of the pipe to allow wildlife movement over the pipe. The hand excavated soil will be compacted as a wedge on each side of the pipe to further assist small animals to cross over the pipe. The drainage pipe will terminate at an energy dissipator.

An energy dissipator will be used to dramatically reduce the velocity of stormwater traveling through the pipe so that its potential to cause soil erosion at the drainage discharge point is negligible. After the Tentative Map was prepared, the Town provided input to the applicant regarding limits on improvements that can be made within property line setbacks. In response, the location of the discharge outfall/energy dissipator on Matadero Creek as shown on the Tentative Map has been moved about 30 feet uphill from the subdivision boundary (and creek) The dissipator will consist of a pipe “T” with perforated extensions of pipe that will dissipate the water at a very low flow rate.

Construction methods to install the drainage pipe and energy dissipator would be similar to those for other proposed utility improvements. Construction for the drainage pipe would involve excavating a narrow trench. Construction activities would result in removal of vegetation within the footprint of the 15-inch pipe and the energy dissipator pipe. Like all other construction activities associated with the proposed project, vegetation could also be damaged by movement of construction workers and equipment.

Like other aspects of the proposed project, regulatory standards and mitigations identified in the IS/MND would ensure that potential impacts from construction/operation of these features on special-status species plant and wildlife, water quality, and cultural resources will be less than significant. For special status species, representative regulations include the federal and state endangered species acts, California Fish and Game Code, federal Migratory Bird Act, and U.S. Army Corps of Engineers and State Water Quality Control Board Regulations promulgated under the federal Clean Water Act. The applicable mitigation measures include mitigation measures include BIO-1 through BIO-8. For water quality, representative regulations include NPDES requirements promulgated under the Clean Water Act and implemented locally as “C.3” requirements, and the Porter-Cologne Water Quality Control Act. Cultural resources analysis and impact determination requirements are defined in CEQA Guidelines Sections 15064.5 and 15126.4. Mitigation measures CR-1 and CR-2 address potential impacts on cultural resources.

Like the proposed footbridge discussed in Section II.A above, the drainage pipe and dissipator would be constructed within the open space easement area. Potential biological resource and water quality impacts, regulatory requirements, and mitigation measures associated with construction in this area are described in Section II.A above. Construction and operation of the drainage pipe and dissipator would not have new or more intensified biological resource or water quality impacts than are identified for the footbridge for other components of the proposed project described in the IS/MND. Implementation of the proposed project consistent with regulatory requirements and mitigation measures identified in the IS/MND for biological resource and water quality impacts would ensure that related impacts would be less than

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significant. Similarly, implementation of the proposed project consistent with the cultural resources mitigation measures included in the IS/MND would reduce potential impacts on cultural resources to less than significant.

Supplementary analysis of the potential effects of constructing the storm water improvements within the open space easement is addressed in Live Oak Associates letter in Attachment D. Live Oak Associates states that the technique planned for partially burying the storm drainage pipe will minimize trenching and disturbance to tree roots while allowing the free movement of wildlife through the open space; consequently, the storm water improvements will have a less- than-significant impact regarding regional wildlife movement (Live Oak Associates 2016, pp. 3- 4).

Construction of Subdrains on Lots 5 and 6. Installation of subdrains on Lots 5 and 6 is recommended by the project geologist and by the Town’s consulting geologist (see Appendix B of the IS/MND) to enhance the stability of a past landslide that traverses both lots. The drains would function solely to redirect existing subsurface flow through and around the unstable area. Like installation of stormwater collection piping and other wet and dry utilities proposed as part of the project, installation of subdrains would involve excavating a narrow trench, placing gravel and four-inch drain pipes in the trench and backfilling the trench.

The subdrains will consist of four-inch perforated PVC pipes installed within the old landslide area as directed by the geotechnical engineer. The trenches will be approximately one foot wide. Oak trees are located within the footprint of the slide. The trenches for segments of pipe to be placed under the drip lines of the oak trees will be initially dug with hand tools to locate roots. Major roots of two inches or greater in diameter will be preserved. Trenches located outside of the drip line or previously exposed by hand digging that are clear of roots may be excavated with a small backhoe.

The subdrains will be connected to solid (non-perforated) four-inch PVC piping to convey the seepage to a point below the mapped landslide area as shown on the Tentative Map. These trenches will be approximately four inches wide and will be dug where they cross into the open space easement boundary. The trenches will be located to minimize impacts to tree roots. A “T” will be installed at the outfall of these pipes with perforated pipes extending a few feet in each direction to dissipate and spread the flows. Similar to the energy dissipator noted above for the storm water pipe, the rate of flow from the subdrains will be managed by the energy dissipator resulting in minimal flows that will not have any significant impact.

As with the storm water discharge pipe and related energy dissipator described previously, construction of the subdrains would not result in potentially significant biological resource or water quality impacts that are not already identified for construction and operation of other components of the proposed project. Those effects are mitigated to less than significant through conformance with regulations and mitigation measures included in the IS/MND that apply to all project construction and operational activities. This is also the case for potential impacts on cultural resources.

Demolition of Existing Structures. Demolition of single-family structures typically involve the use of standard construction equipment such as a small bulldozer and hand held power tools. Demolition of an existing structure is subject to regulatory requirements related to handling and

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disposal of hazardous materials, including asbestos and lead based paint. Mitigation measure HAZ-1 in the IS/MND (pp. 65-66) identifies applicable regulatory requirements and the related performance standards that must be followed to assure that related impacts would be reduced to less than significant. If such materials are found, the regulations identify how such materials are removed, transported, and disposed to ensure public health and safety is maintained.

III.A Lack of Special-Status Species Information

The commenter asserts that there is insufficient information regarding the potential presence of special status species at the Project site. However, the methodology used in the IS/MND for evaluating special-status plant species impacts is standard professional practice in preparing CEQA documentation. Please refer to the IS/MND (pp. 39-41). The initial field reconnaissance is intended to record observable plant species and habitats and to determine the potential for presence of plant species that cannot be reliably observed during the reconnaissance given peak blooming seasons that occur outside the reconnaissance date. Where any potential exists for special-status plant species to be present based on field conditions (e.g. presence of suitable habitat) and review of records of occurrence in the project site vicinity, mitigations are included in CEQA documentation. Based on this methodology, the IS/MND (pp. 39-41) identifies that there is low potential for five special-status plant species to occur on the project site due to the presence of marginally suitable habitat. A brief description of each species is included. Mitigation typically requires that focused surveys for such species be conducted during their respective peak blooming seasons to determine their presence or absence. Mitigation measure BIO-1 in the IS/MND (pp. 40-41) is proposed precisely for this purpose. It requires focused plant surveys for the five special-status plant species prior to construction and sets forth the steps to be undertaken in the event any such species are discovered, to reduce impacts to less than significant.

CEQA does not require focused plant surveys to be conducted prior to a lead agency’s determination to approve or deny a project. CEQA Guidelines Section 15126.4(a)(1)(B) permits a lead agency to include measures that specify performance standards to mitigate a significant effect of a project that can be accomplished in more than one specified way. Mitigation measure BIO-1 identifies the specific performance standards that must be met in conducting focused surveys. It further identifies specific actions that must be taken to reduce impacts to less than significant if such species are observed during the focused surveys in areas where they could be impacted by construction or operation of a project. In this regard, mitigation measure BIO-1 does not constitute deferral of mitigation.

To proactively advance the implementation of mitigation measure BIO-1, the applicant retained WRA, a qualified biological consulting firm, to conduct focused surveys for the four species whose peak blooming season occurs before or within the spring. The results of the surveys are included in Attachment G. None of the four species were observed. The focused surveys covered all areas that could be affected by construction and operation of subdivision improvements, areas within the open space easement where the footbridge, trail pathway, landslide subdrain system, and storm drainage pipeline/energy dissipator improvements are planned. A focused survey for Congdon’s tarplant will be conducted in the fall during its peak blooming season, with a complete report on all focused surveys and results delivered at that time, before any construction occurs.

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III.B Asbestos and Lead-Based Paint

The commenter states that the IS/MND does not adequately disclose the existence of hazardous materials in existing structures on-site that will be demolished as part of the Project. That is not the case. The IS/MND follows standard professional practice in preparing CEQA documentation for analysis of these impacts. The IS/MND includes discussion of potential impacts on public health and safety from demolishing existing structures. Impacts could occur if the structures contain asbestos or lead-based paint. The state regulates asbestos and lead-based paint containing materials, including where such materials may be present and released to the environment through demolition of existing structures. The related regulatory requirements are described in mitigation measure HAZ-1 in the IS/MND (p. 65).

There is no requirement in CEQA or elsewhere that a determination of the presence of these materials in a building proposed for demolition must occur prior to a lead agency’s consideration to approve a project that proposes such demolition. Nor does the commenter cite any authority to the contrary. Mitigation measure HAZ-1 contains reference to the performance standards (regulatory requirements) that must be met prior to, during, and after demolition. As described in CEQA Guidelines Section 15126.4(a)(1)(B), “Formulation of mitigation measures should not be deferred until some future time. However, measures may specify performance standards which would mitigate the significant effect of the project and which may be accomplished in more than one specified way.” Implementation of the mitigation measure does not, therefore, constitute deferred mitigation and would reduce potential public health and safety impacts to less than significant.

IV.A Low Threshold for Requiring an EIR

An agency must prepare an EIR whenever it is presented with substantial evidence of a fair argument that a project may have a significant effect on the environment, even if there is also substantial evidence to indicate that the impact is not significant. CEQA expressly defines “substantial evidence” as “fact, a reasonable assumption predicated on fact, or expert opinion supported by fact.” Public Res. Code Section 21080(e)(1). While the commenter provides extensive comments on the content of the IS/MND, which are addressed below, the commenter does not provide substantial evidence that that the IS/MND fails to disclose one or more significant impacts of the proposed project.

IV.B Heritage Oaks

The commenter states that the IS/MND’s analysis of potential impacts on Heritage Oaks is uncertain, and does not specify adequate mitigation measures. HortScience provided a supplemental evaluation of the project’s impacts to Heritage Oaks in a Revised Arborist Report dated April 2016. The Revised Arborist Report is included as Attachment H. In that report, HortScience clarifies the number of Heritage Oaks to be removed as part of the proposed project due to refinement of the development plans. Nine oaks are to be removed within the proposed road alignment, six oaks are to be removed that are adjacent to the new road, and nine oaks are to be removed within the slide repair. Of these 24 trees, 19 are Heritage Oaks. An additional five trees, all Heritage Oaks, will be removed to allow construction of the access road. Of the 24 Heritage Oaks to be removed, five have low suitability for preservation. HortScience also identifies three Heritage Oaks along the access road previously listed for removal that will be

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preserved. In sum, in the area where development will occur a total of 129 trees will be preserved, including 108 Heritage Oaks. In addition, there are 285 additional Heritage Oaks in the open space easement area, all of which will be preserved, and which will not be significantly impacted by the very limited construction activities in the easement area. These clarifications do not affect the adequacy of the IS/MND’s analysis, nor its conclusion that impacts on Heritage Oaks would be less than significant.

All revised arborist reports from 2014 to the present include a description of the impacts to trees on the development site from grading of the road, drainage, potential driveways, access roads and the pedestrian path. HortScience identifies 23 trees as being close to the road and access road improvements. HortScience concludes that the 23 trees will tolerate the impacts from the proposed improvements because of necessary precautions that will be required during demolition and construction (see mitigation measure BIO-8).

The IS/MND and the HortScience Revised Arborist Report consider impacts to trees from the proposed subdivision improvements (road, pathway etc.). The exact location of future residential structures is not known at this time. The Tentative Map and the November 2014 HortScience report include information known at this time regarding Heritage Oaks that may require removal due to construction of subdivision improvements. The only proposed project subdivision improvements planned within the open space easement include the footbridge, meandering path, landslide subdrain system, and storm water drainage pipeline/dissipator system. HortScience concludes that the future construction of any houses within the envelopes shown in the May 22, 2015 Proposed Tentative Map will not result in any more tree loss because of the Tree Protection Guidelines required under mitigation measure BIO-8.

Tree Protection Zone Information. HortScience also prepared a supplemental Response Letter, dated April 20, 2016, clarifying previous recommendations for Tree Protection Zones that appeared inconsistent. The Response Letter is included as Attachment I. The alleged discrepancies identified in public comments regarding inconsistent protection zones are in fact different recommendations for different phases of the project. Table 5 in the Response Letter provides HortScience’s recommended protection zones for 42 trees within the building envelopes or other easements and made binding through mitigation measure BIO-8. Table 5 further describes the ideal recommended protection zones guiding the design and construction of improvements adjacent to trees on individual lots. Any intrusion into the protection zones must receive prior approval of and be monitored by the Project Arborist (see mitigation measure BIO- 8).

IV.B.1 Heritage Oak Preservation Mitigation

Heritage Oak Tree Mitigation. Mitigation measure BIO-8 can be refined to provide more specific guidance for Heritage Oak replacement and preservation and to clarify the link between the HortScience report and recommendations for protecting trees to be preserved. For this purpose, the following revisions to mitigation measure BIO-8 are recommended (deletions shown in strikethrough text/additions shown as underlined text):

BIO-8. The project applicant shall prepare and implement a tree replacement plan pursuant to municipal code Title 12, Article 3 for all Heritage Oaks to be removed as a result of project implementation. The plan shall be subject to review and approval of the Town, and shall be

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implemented as a subdivision improvement. The tree replacement plan shall specify the following:

. A final tree survey showing all Heritage Oaks within all subdivision improvement impact areas that require removal;

. Heritage Oaks to be removed shall be replaced at a minimum ratio of three new replacement trees for every one tree removed. Replacement trees shall be of the same species that will be removed;

. All replacement trees must be grown in deep five-gallon containers and the trees shall not have been in the containers for more than two years;

. Replacement trees must be spaced such that they do not compete with one another and do not compete with established vegetation. Trees shall be planted a sufficient distance (as determined by a certified arborist) away from planned subdivision improvements or improvements on individual lots (if known) to avoid damage to improvements or trees. Replacement trees should be planted as near to the location of removed trees as possible subject to the above specifications. A tree planting plan shall be prepared which shows the proposed tree planting locations subject to these specifications; and

. The viability of the replacement trees shall be monitored by the applicant for two years from the date they are planted. Failed trees shall be replaced no later than 2.5 years after their initial planting.

For all Heritage Oaks to be retained the project applicant shall fully implement the protection tree preservation methodology guidelines for tree preservation contained in the HortScience 2014 revised project arborist report (pp. 13-15). The tree protection zones referenced in the recommendations are defined in the Specific Tree Protection Zones table found in the HortScience report (p. 14) and the tree numbers refer to those included in the HortScience report and reflected on Sheets 3 and 4 of the proposed Tentative Map. The recommendations are as follows:

Design Recommendations

1. All plans affecting trees shall be reviewed by the Consulting Arborist with regard to tree impacts. These include, but are not limited to, demolition plans, grading and utility plans, landscape and irrigation plans.

2. Evaluate the design of the path to minimize grading and provide as much room from trees #109, 110, 112, 113, 115, 116118, 121 and 122 as possible. By placing the path on grade, or as close to existing grade as possible, and providing as much room from trees as possible, root loss will be minimized.

3. To the extent feasible, Uunderground services including utilities, sub-drains, water or sewer shall be routed around the tree protection zone. Where encroachment cannot be avoided, special construction techniques such as hand digging or tunneling under roots shall be employed where necessary to minimize root injury.

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4. A tree protection zone must be established for trees to be preserved, in which no disturbance is permitted without the prior review by and approval of the Consulting Arborist. Tree protection zones for trees identified for preservation are identified in the following table adjacent to the subdivision improvements are identified in the Revised Arborist Report. No grading, excavation, construction or storage of materials shall occur within a Tree Protection Zone. Trees not given specific Tree Protection Zones and not designated for removal shall be fenced at the dripline in all directions.

5. As trees withdraw water from the soil, expansive soils may shrink within the root area. Therefore, foundations, footings and pavements on expansive soils near trees should be designed to withstand differential displacement.

Underground services including utilities, sub-drains, water or sewer shall be placed indesigned to avoid tree protection zones, where possible. Where not possible, special construction techniques, such as boring or hand trenching and threading of utilities beneath roots 2 inches in diameter and larger must be employed.

6. Tree Preservation Notes, prepared by the Consulting Arborist, should be included on all plans.

7. Do not lime within 50 feet of any tree. Lime is toxic to tree roots.

8. Any herbicides placed under paving materials must be safe for use around trees and labeled for that use.

9. Irrigation systems must be designed so that no trenching will occur within any tree protection zone.

Pre-Construction Treatments and Recommendations

1. The construction superintendent shall meet with the Consulting Arborist before beginning work to discuss work procedures and tree protection.

2. Fence all trees to be retained to completely enclose all tree protection zones prior to demolition, grubbing or grading. Fences shall be six (6) foot high chain link or equivalent as approved by the Consulting Arborist. Fences are to remain until all grading and construction is completed.

3. Pruning trees to provide construction and access clearance will be required. Trees #3, 4, 7, 23, 25, 27, 28, 33, 66, 95, 101, 121, 122 and 125 have been preliminarily identified for pruning to provide construction and road clearance. Additional trees may require pruning for pedestrian clearance over the path.

4. Prune trees to be preserved to clean the crown and to provide clearance. All pruning shall be done by a State of California Licensed Tree Contractor (C61/D49). All pruning shall be done by Certified Arborist or Certified Tree Worker in accordance with the Best Management Practices for Pruning (International Society of Arboriculture, 2002) and adhere to the most recent editions of the American National Standard for Tree Care Operations (Z133.1) and Pruning (A300).

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5. All tree work shall comply with the Migratory Bird Treaty Act as well as California Fish and Wildlife Code Sections 25003-3513 to not disturb nesting birds. To the extent feasible tree pruning and removal should be scheduled outside of the breeding season. Breeding bird surveys should be conducted prior to tree work. Qualified biologists shall be involved in establishing work buffers for active nests.

6. Have brush from the pruning and removal operations chipped and spread beneath the trees within the tree protection zone. Mulch shall be 2 to 4 inches in depth and kept a minimum of 3 feet from the base of the trees.

Recommendations for Tree Protection during Construction

1. Prior to beginning work, the contractors working in the vicinity of trees to be preserved are required to meet with the Consulting Arborist at the site to review all work procedures, access routes, storage areas and tree protection measures.

2. Except as absolutely necessary, Nno grading, construction, demolition or other work shall occur within any tree protection zone. Any exceptions must be approved and monitored by the Consulting Arborist to ensure that trees are protected.

3. Fences have been erected to protect trees to be preserved. Fences define a specific tree protection zone for each tree or group of trees. Fences are to remain until all site work has been completed. Fences may not be relocated or removed without permission of the Consulting Arborist.

4. Construction trailers, traffic and storage areas must remain outside fenced areas at all times.

5. Prior to grading, pad preparation, excavation for foundations/footings/walls, trenching, trees may require root pruning outside the tree protection zone. Any root pruning required for construction purposes shall receive the prior approval of, and be supervised by, the Consulting Arborist.

6. If accidental injury should occur to any tree during construction, it shall be evaluated as soon as possible by the Consulting Arborist so that appropriate treatments can be applied.

7. No excess soil, chemicals, debris, equipment or other materials shall be dumped or stored within the tree protection zone.

8. Any additional tree pruning needed for clearance during construction must be performed by a Certified Arborist and not by construction personnel.

IV.B.2 Replacement of Certain Trees Other Than Heritage Oaks.

Project compliance with Town municipal code requirements, including Municipal Code Section 9-1.607, is sufficient to reduce any impacts to non-heritage oak trees from the proposed project to less than significant. Municipal Code Section 9-1.607 includes development regulations for replacement of trees that are larger than 20 inches in circumference measured at a point four feet from the ground. No such trees are to be removed unless they must be removed to facilitate the

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locating of public and/or private roadways, the placement of structures within the proposed rights-of-way, or for the rough grading of driveways and/or parking areas. Trees removed for this purpose must be replaced at a ratio of two new trees for every one removed. Diseased or dead trees removed for this purpose need not be replaced subject to evidence verifying the condition of the trees. Project compliance with these requirements is mandatory and the applicant has incorporated this mandatory compliance into the project plans (Attachment J). To ensure such tree replacement is completed by the applicant consistent with the municipal code requirement, the Town will also condition approval of the project on the applicant’s preparation of a non- heritage oak tree replacement plan. The plan will be subject to review and approval of the Town, and shall be implemented as a subdivision improvement. The tree replacement plan for non- heritage trees more than 20 inches in circumference shall specify the following:

. Trees to be removed shall be replaced at a minimum ratio of two new replacement trees for every one tree removed, excluding trees that are determined to be diseased or dead. Replacement trees shall be of the same species as the tree removed;

. All replacement oak trees must be grown in deep five-gallon containers and the trees shall not have been in the containers for more than two years;

. Replacement trees must be spaced such that they do not compete with one another and do not compete with established vegetation. Trees shall be planted within sufficient distance from planned subdivision improvements (as determined by a certified arborist) as to avoid damage to improvements or trees or within a sufficient distance from anticipated improvements on individual lots if known. Replacement trees should be planted as near to the location of removed trees as possible subject to the above specifications. A tree planting plan shall be prepared which shows the proposed tree planting locations subject to these specifications; and

. The viability of the replacement trees shall be monitored for two years from the date they are planted. Failed trees shall be replaced no later than 2.5 years after their initial planting.

The commenter claims that the IS/MND fails to address how oaks will be affected by the construction of new homes and driveways. Potential effects from construction of new homes and driveways on additional oaks is speculative and premature at this time, since the proposed project only involves a subdivision and associated subdivision improvements and not any particular residential development. The proposed Tentative Map identifies for each lot a potential building envelope and driveway which could be constructed without the removal of any Heritage Oaks. While these driveway and house configurations are not binding on a future home builder, they are evidence that the lots can be developed without additional Heritage Oak removal. While it is conceivable that an owner proposing to develop a lot could propose a house design outside these envelopes that could cause removal of or impact on additional Heritage Oaks, whether this would happen is entirely speculative at this stage. In addition, the Town’s tree protection ordinance restricts the removal of Heritage Oaks and other trees with a circumference of 20 inches or more, and subjects any proposed removals to replacement ratios. Further analysis at this time of potential impacts from future housing designs would therefore be premature and speculative. Finally, any future proposal to remove additional Heritage Oaks or other trees with a circumference of 20 inches or more in connection with a home development will be subject to Town review and approval, and likely trigger a requirement that replacement trees be provided.

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IV.C.1 Existing Hydrological Setting

Existing stormwater infrastructure and storm water conditions are briefly described in the IS/MND (pp. 1-2, p. 69). There currently is no organized storm water control system on the site. Rainfall from existing undisturbed surfaces and from impermeable surfaces (e.g. roofs and paved areas associated with the two existing residences) infiltrates into the soil and may move by overland sheet flow downslope to Matadero Creek.

As described in the IS/MND, the proposed project would alter existing hydrological conditions. This will occur primarily through introducing new impervious surfaces such as the extension of Charles Avenue and widening of the existing segment of the road, sidewalks, driveways, and roofs that result in modification of the volume and rate of storm water that flows from the site under existing/natural condition. Storm water runoff from these surfaces will be managed using the planned storm water control system. Details of the system are included on sheet 7 of the Tentative Map included in Appendix A of the IS/MND. By regulatory requirement, the storm water management system is designed to pre-treat storm water to protect the quality of downstream receiving waters, promote percolation/recharge, limit the rate of runoff from the site to pre-project conditions, and dispose of storm water in a manner that does not cause soil erosion and water quality impacts on Matadero Creek.

There are no standing surface water bodies within the boundary of the project site. Matadero Creek, which flows intermittently at its reach adjacent to the site, traverses the western and southern boundary of the site. Based on the California Water Quality Control Board’s Clean Water Act Section 303(d) listing protocol, water quality in Matadero Creek has been compromised by trash and by the pesticide diazinon. The sources of the pollutants include illegal dumping (trash) urban runoff, and storm sewers (http://www.swrcb.ca.gov/water_issues/programs/tmdl/2010state_ir_reports/00685.shtml). Diazinon is a pesticide most commonly used in agricultural applications to kill insects and mites that damage crops; domestic uses include cockroach, ant, and beetles control.

IV.C.2 Project Effect on Water Quality

If not properly managed and pre-treated, storm water runoff from impervious surfaces of the project site could contain urban pollutants such as oil, grease, sediment, and household fertilizers and pesticides at levels that could contribute to Matadero Creek water quality impacts.

Project compliance with regulatory requirements, including C.3 requirements (and preparation of a storm water control plan [“SWCP”]) and General Construction Permit (and preparation of a SWPPP) is sufficient to reduce water quality impacts of the proposed project to less than significant. Compliance with these requirements is mandatory for qualifying projects. Given its characteristics, the proposed project is a qualifying project and is subject to the requirements. These regulations include specific performance standards that must be met to achieve their respective goals of reducing water quality impacts as described below.

The C.3 requirements are promulgated by the Town to ensure compliance with the Town’s NPDES Permit as referenced in the IS/MND (p. 68). The C.3 standards require site designs for new developments and redevelopments to minimize the area of new roofs and paving. Where feasible, pervious surfaces should be used instead of paving so that runoff can infiltrate to the

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underlying soil. Remaining runoff from impervious areas must be captured and used or pre- treated using bioretention or other measures to filter out urban pollutants prior to its discharge. Increased runoff flow rate must be managed so that post-project runoff rates do not exceed estimated pre-project rates. This is necessary where increased flow is otherwise likely to cause increased potential for erosion (“hydromodification”) of receiving waters, including creek beds and banks, silt pollution, or other adverse impacts on beneficial uses of receiving waters due to increased erosive force.

To demonstrate compliance with C.3 requirements, a SWCP must be prepared according to rigorous standards contained in the requirements. The SWCP must, among other specifications, identify site design measures, source control measures, and treatment methods that will be used to control and treat storm water prior to its discharge. A conceptual SWCP was prepared by the applicant and is shown on sheet 7 of the Tentative Map in Appendix A of the IS/MND. Preparation of a conceptual SWCP is the first step in the process of demonstrating C.3 compliance. The SWCP includes a number of stormwater control features including, but not limited to: pervious pavement, self-retaining areas, preserved open space, a bioretention area, and storm water detention. Additional measures such as storm drain labeling and beneficial landscaping (to minimize irrigation runoff, pesticides, fertilizers, and to promote treatment) are also included.

The applicant’s SWCP and related C.3 compliance input worksheets were reviewed by an independent consulting environmental engineer retained by the Town. The purpose was to determine whether the conceptual SWCP complies with C.3 regulations, which is required prior to the Town’s consideration of the proposed project for approval. In a memorandum dated June 25, 2015, the consulting environmental engineer concluded that the SWCP is conceptually acceptable and that the Town may approve the conceptual SWCP subject to conditions. The conditions generally address the need for additional details for some aspects of the SWCP (Letter from Jill Bicknell, P.E., Eisenberg, Olivieri & Associates June 25, 2015). The additional detail will be incorporated into a final SWCP whose implementation will be required as a condition of approval and whose implementation will be monitored by the Town consistent with C.3 regulations. Approval of the final SWCP is not required prior to the Town’s consideration of the proposed project. The final SWCP will be prepared as part of the final improvement plan process and prior to the Town’s approval of a final subdivision map.

Given the purpose of the C.3 regulations, and the confirmed compliance of the project with those regulations, the proposed project’s operational impacts on water quality from urban pollutants and erosion/hydromodification of Matadero Creek would be less than significant as described in the IS/MND.

Construction Phase Water Quality Effects. The C.3 requirements described above are separate from, and in addition to, requirements for erosion and sediment control and for pollution prevention measures during construction. These latter requirements are also a component of the Town’s required compliance with Clean Water Act legislation as promulgated by the California Water Quality Control Board through its NPDES General Permit for Storm Water Discharges Associated with Construction Activity. An overview of the NPDES program is provided in the IS/MND (pp. 68-69). To demonstrate that a new project which disturbs one or more acres of land will minimize potential effects on water quality during the construction phase, a SWPPP

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must be prepared by the project applicant. The measures in the SWPPP must meet precise performance standards.

A SWPPP must identify all construction activities with potential to enable storm water to come into contact with potential sources of water pollution. “Construction” refers to actions that result in land disturbance, including clearing, grading, excavating, and other similar activities. Stockpiles, borrow areas, concrete truck washouts, fueling areas, material storage areas and equipment storage areas are also considered to be areas of land disturbance. During construction, the primary concern is exposure of soils to the erosive effects of rainfall and concentrated storm water runoff. If sediment and erosion controls and good housekeeping practices are not followed, construction activity can result in soil erosion and the discharge of significant amounts of sediment and other pollutants to receiving waters.

A SWPPP is a written, enforceable document that describes the pollution prevention practices and activities that will be implemented on the site. It includes identification of potential pollutant sources, description of controls to reduce pollutants, and control maintenance/inspection procedures. It also would include descriptions of the site and of each major phase of the planned activity, the roles and responsibilities of contractors and subcontractors, and the inspection schedules and logs. Construction of infrastructure, including storm drainage systems, is a phase of the project that would be described in the SWPPP. For this reason, the SWPPP would describe pollution prevention practices that would be employed to minimize erosion of all exposed soil surfaces, including those associated with construction of the proposed footbridge, storm drainage discharge pipe, and storm water dissipator improvements as described in Section II.B above. There is no evidence that SWPPP pollution prevention measures cannot be effectively employed on slopes. Slope inclination and length instead affects the selection and placement of appropriate best management practices, which routinely occurs throughout California in steeply sloped areas. Representative Best Management Practices (BMPs) for soil erosion control on slopes are identified in the 2009 California Stormwater BMP Handbook for Construction Activities prepared by the California Stormwater Quality Association.

A SWPPP must be approved by the Town prior to initiation of any ground disturbing activity at the site and implementation of control measures must be monitored and reported. Hence, implementation of the SWPPP will reduce potential impacts on water quality during the construction phase to less than significant.

As described above and consistent with IS/MND conclusions, required compliance with regulatory requirements will ensure that water quality impacts from project-related activities during construction and during operations would be reduced to less than significant. No mitigation measures are required.

IV.C.3 Flooding and Erosion Effects

The commenter expresses concern that the IS/MND does not adequately analyze potential impacts affecting downstream erosion. By way of background, bank erosion occurring downstream of the project site on Matadero Creek has apparently been exacerbated by a number of human causes and natural causes. Those causes are unrelated to the rate or volume of storm water runoff from the project site in Matadero Creek that occurs under existing conditions. If the rate of storm water runoff from the site discharged to the creek were to increase under post-

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project conditions, the erosive effects of flow in the creek could incrementally increase. This change would have potential to cause hydromodification and decreased water quality from increased sedimentation and turbidity.

As described above in Section IV.C.2, the applicant’s SWCP has been reviewed by the Town’s independent consulting environmental engineer for consistency with C.3 requirements. The proposed project qualifies as one for which the rate of storm water discharge from the site under post-project conditions is not permitted to exceed pre-project conditions. The SWCP preparation and approval process includes a requirement to model pre-project storm water conditions and compare them to post-project conditions (with implementation of SWCP control measures) to assure that this requirement is met. The modeling conducted for this purpose was reviewed by the Town’s independent consultant and found to be acceptable. Therefore, there is no evidence that the proposed project would exacerbate existing downstream erosion of the bed or banks of Matadero Creek.

The detention basin is a control measure included in the SWCP. Its operation is one component of the overall SWCP control measure system. As noted above, the SWCP system has been reviewed to verify that the post-project storm water runoff rate to Matadero Creek will not exceed pre-project rates.

IV.D Aesthetic Effects

Concern was raised by the commenter regarding the project’s impacts on private views and nearby trails. The only potential visual impacts from the proposed project are on the views of and through the project site from a small number of adjacent private properties. There are four to five private residential properties adjacent to proposed lots 1 and 4 that have some limited views into the project site. These private residential properties adjacent to lots 1 and 4 could experience a change to their views, including a potential loss to some distant views across the project site toward the west. Notably, the existing views across the site from these adjacent residents toward the west are already constrained by existing tress. While a few adjacent neighbors may presently enjoy limited private views across the project site which could be obstructed, the obstruction of a few private views is not a significant impact under CEQA. (Bowman v. City of Berkeley, (2004) 122 Cal.App.4th 572, 586, the “obstruction of a few private views in a project’s immediate vicinity is not generally regarded as a significant environmental impact.”)

CEQA distinguishes whether a project will adversely affect the views of particular persons (not a significant impact) and whether a project will adversely affect the environment of persons in general (potentially a significant impact). (§ 21083, subd. (c).) In Assn. for Protection of Environmental Values in Ukiah v. City of Ukiah (1991) 2 Cal.App.4th 720, 720, the court held that the proposed project did not create a potentially significant aesthetic impact because the “height, view and privacy objections... [that affect] only a few of the neighbors... did not affect the environment of persons generally.” (Id. at 734.) No authority is presented in the public comments to support the argument that CEQA is intended to afford private view rights to a few neighbors adjacent to a proposed project. In Ocean View Estates Homeowners Association, Inc. v. Montecito Water District (2004) 116 Cal.App.4th 396, the determining factor in the court’s analysis was the photographic evidence showing a fair argument that a portion of the reservoir was visible from public trails.

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As noted in the IS/MND for this project, there are no Town-identified scenic vistas in or near the project site, and the site is not within the view shed of a scenic highway. There are no public paths or trails in the vicinity of the project site with views that could potentially be affected by the project. Sheet 6 of the Tentative Map Appendix A of the IS/MND shows a pathway easement ending at the northeastern corner of the project site, but this easement dead-ends at the project’s boundary and does not appear to be active. The view from the “Scenic Stegner Path” that runs just west of the property’s western boundary is obscured from the project site due to thick wooded overgrowth and will be protected by an open space easement. Moreover, there are no existing public pathways on the project site or any public park adjacent to or nearby from which the project would block public views. Photographs taken from the Stegner Path and from Edgerton Road provide substantial evidence that public trails in the vicinity of the project site will not be substantially affected by the proposed project. These photographs are included as Attachment K.

The City has not adopted a view protection ordinance. The Town Municipal Code Sections 10- 2.701 and 10-2.702 provide guidelines, not mandatory regulations barring any impairment of private views, that the Town shall consider when approving the construction of new homes. However, none of the listed guidelines under these sections directly address impacts on private views. Any future construction of new homes shall comply with Municipal Code Sections 10- 2.701 and 10-2.702, but these potential effects are speculative and premature to analyze at this stage. The proposed project only involves a subdivision and associated subdivision improvements and not any particular residential development. The only proposed project subdivision improvements include the footbridge, meandering path, landslide subdrain system, and storm water drainage pipeline/dissipator system, all of which are not reasonably likely to obstruct off-site views.

As the IS/MND demonstrates, the proposed project would not affect any recognized scenic vistas, or any views from public parks and trails. Even to the extent that impacts on private views are relevant to a CEQA analysis, the fact that the project would impact only a few private views supports the conclusion that the visual impact in this case would not be significant. Substantial evidence supports the conclusion that the project would not result in significant aesthetic impacts.

IV.E Wildlife Effects

Open space easement improvements/wildlife movement. Concern has been expressed that construction of improvements within the proposed 7.22-acre open space easement area along Matadero Creek could result in significant impacts on wildlife movement. The open space easement area represents approximately 40 percent of the total area of the 18.18-acre site. As described in Sections II.A and II.B above, the proposed project does include very limited improvements within the open space easement area. These include a pathway, the pedestrian footbridge over Matadero Creek, a storm drainage pipe and associated storm water energy dissipator, and a subsurface landslide stabilization subdrain system. The types and intensity of improvements proposed are described in the aforementioned sections.

The pathway and footbridge are the only improvements of note that are planned in the open space easement area. The footbridge would span Matadero Creek without affecting the creek bed or banks. The area of the bridge footprint constitutes approximately .0004 percent of the total open

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space easement area. The storm drainage pipe/dissipator system and the landslide subdrain system improvements would have minimal surface expression. The storm drainage pipe would be a maximum of 15 inches in diameter. It would be partially buried in the ground such that its vertical surface expression would be minimal. The pathway would run near the north edge of the open space easement area and connect to the bridge.

As described in Sections II.A and II.B above, Live Oak Associates and H.T. Harvey & Associates provided supplemental information regarding the potential effects of the trail/footbridge and storm drainage improvement on wildlife movement. Both concluded that construction phase effects would be less than significant. Both also concluded that the improvements would have a less-than-significant impact on the ability of wildlife to move through the open space corridor.

Wildlife Movement and Subdivision Improvements/Fencing. Concern has been expressed that construction and use of the subdivision improvements (e.g. roads, homes, fencing, etc.) would degrade the quality of the site as a wildlife corridor. Fencing and its effect on the movement of wildlife through the site is of special concern. Both Live Oak Associates and H.T. Harvey & Associates provided supplemental evaluations of the potential effects of these subdivision improvements, with a focus on fencing. The evaluations are included in their letters previously discussed and included as Attachments D and E, respectively. Live Oak Associates states that from a regional wildlife movement/habitat perspective, the site as a whole represents a relatively small landscape for regional wildlife, representing about five percent of an average deer home range and less than one percent of a bobcat or coyote home range. Live Oak Associates concludes that despite the small groups of deer that have been seen on the site from time to time, the site from a pure habitat perspective is insignificant for the local deer population. It is further stated that even assuming the entire forage capacity of the site was removed, the impact on the regional population would be too small to measure (Live Oak Associates 2016, pp. 2-3).

Live Oak Associates also clarifies information it provided for the IS/MND regarding fencing and its impact on movement of wildlife within the open space easement. In its letter of November 11, 2014 that was referenced in the IS/MND, Live Oak Associates concluded that deer will continue to access the site with regularity assuming that the individual lots are not surrounded by impermeable fencing. Live Oak Associates clarifies that this conclusion was based on the assumption that any fencing placed in the open space easement area between lots 5-9 and along the western boundaries of lots 5-9 would be wildlife friendly fencing. This assumption is verified by the fact that the Town will require wildlife friendly fencing in these locations as a design feature to be included as a condition of approval.

H.T. Harvey & Associates’ letter includes extensive discussion about important wildlife movement corridors in the CEQA context and about the portions of the site that serve this function. H.T. Harvey & Associates states that the CEQA Guidelines related to wildlife movement require an assessment of whether a project would “interfere substantially with the movement of any native resident or migratory species or with established native resident or migratory wildlife corridors.” H.T Harvey & Associates’ historical practice has been to interpret “substantial interference” as pertaining to movement that has biologically important implications – that is, movement necessary to help sustain populations (e.g., by allowing immigration of new individuals) and maintain genetic diversity within populations. Such interpretation takes into

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account regional wildlife movements, and movement between populations, rather than movement by animals at a scale as small as an 18-acre project site, or between such a small site and adjacent areas. As a result, H.T. Harvey & Associates states that the appropriate assessment of the proposed project’s impacts on wildlife movement focus on whether the project would substantially interfere with the ability of animals to move between large off-site habitat areas (such as between large habitat patches near Altamont and Moody Roads to the south and Arastradero Preserve to the northwest), not on whether animals can move as freely within the site as they currently do, whether animals have access to particular areas on the site, or whether animals can move on and off this particular site via less important pathways (H.T. Harvey & Associates 2016, pp. 1-2).

Based on its review of the Live Oak Associates 2006 wildlife corridor study that was referenced in the IS/MND and in the Shute Letter comments, and based on review of conditions in the field, H.T. Harvey & Associates concludes that the Matadero Creek corridor provides opportunities for larger and/or more mobile species to move long distances using this corridor (e.g., between large habitat patches near Altamont and Moody Roads to the south and Arastradero Preserve to the northwest). In addition, the resources provided by the well-vegetated drainages in the Matadero Creek watershed, as well as native vegetation present within the low-density residential areas throughout the watershed, provide habitat that supports many of these animals within their home ranges. The biological importance of the Matadero Creek corridor for wildlife movement includes both long-distance dispersal movements (e.g., by a mule deer, coyote, or mountain lion dispersing several miles in a night) and short-distance movements and genetic exchange among individuals that make small portions of the corridor part of their home range. The observation of numerous game trails within the proposed Matadero Creek open space easement indicate that the easement area is connected to similarly suitable areas for wildlife movement both upstream and downstream of the project site (H.T. Harvey & Associates 2016, p. 2).

For the reasons noted above, H.T. Harvey & Associates concludes that it does not expect that future construction on the land upslope from the proposed Matadero Creek open space easement corridor to result in a substantial reduction in the use of the creek corridor for wildlife movement. H.T. Harvey & Associates also states that species such as mule deer and coyotes that currently occur on the site have to be sufficiently habituated to, or tolerant of, residential land uses on other immediately adjacent parcels to be moving through the site to begin with, given that the project site is embedded within a fairly extensive matrix of low-density residential development. Furthermore, the dense vegetation present in much of the on-site portion of the Matadero Creek corridor, coupled with the width of the open space easement area, would allow animals to move through this corridor relatively unaffected by activities on residential land uses upslope (H.T. Harvey & Associates 2016, pp. 2-3).

Regarding the wildlife corridor value of the site outside the open space easement area, H.T. Harvey & Associates evaluated potential wildlife movement corridors represented in the 2006 Live Oak Associates study and further considered movement potential in light of existing fencing constraints and post-project fencing conditions. H.T. Harvey validated that the corridor along the northern boundary of the site is valuable for wildlife movement. If the proposed project includes wildlife friendly fencing along the northern and eastern borders of the site, it would improve potential wildlife movement through this portion of the site, as compared to the existing non wildlife friendly fencing on those boundaries. However, even if the fencing isn’t wildlife friendly, H.T. Harvey concludes that wildlife movement through the corridor to the

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North/Northeast will be at least as good as under current conditions (H.T. Harvey & Associates 2016, p. 3).

H.T. Harvey & Associates also discusses at length the potential project effects on smaller movement pathways, such as those identified in the 2006 Live Oak Associates study as extending from the east side of the site to Natoma Road (H.T. Harvey & Associates 2016, p. 4). In short, H.T. Harvey & Associates concludes that the proposed project may inhibit or preclude the use of these much smaller-scale movement pathways, but that these impacts would not be significant. This conclusion is based on the determination that the movement that occurs along these smaller pathways does not contribute substantially to regional movements or exchange of individuals or genes among populations. A conclusion is also drawn that movement from the site to Natoma Road and beyond (e.g. Poor Clare’s orchard) will likely continue to be possible via Charles Avenue, as wildlife often move along minimally traveled roads.

In summary, H.T. Harvey & Associates finds that the proposed project will have a less-than- significant impact on wildlife movement corridors because the two most important corridors – Matadero Creek and the corridor to the north/northeast will continue to be available after the project is constructed (H.T. Harvey & Associates 2016, p. 3). The proposed project will not result in substantial interference with established or biologically important movement pathways and animals will still be able to access and use the biologically important movement pathways identified in the 2006 Live Oak Associates wildlife corridor study (H.T. Harvey & Associates 2016, p. 4). These findings provide additional support for the conclusions in the IS/MND.

V. Cumulative Impacts

Cumulative Impact Scenario and Cumulative Impacts. CEQA Guidelines Section 15130(b)(1)(a) identifies options for formulating a cumulative impact scenario against which the contribution of a proposed project’s effects can be assessed for cumulative significance. One such scenario is to compare the contribution of a proposed project to the cumulative impacts of projects contained in a list of past, present, and probable future projects that would produce related cumulative impacts.

The Matadero Creek Restoration and Bank Stabilization Project (“restoration project”) is the only project represented by commenters on the IS/MND to be relevant to a discussion of the proposed project’s cumulative impacts. As confirmed by the Town, the restoration project is the only current, known probable future project within the vicinity of the project site with potential to contribute to related cumulative impacts. It is located approximately 0.9 miles downstream on a 350-foot segment of Matadero Creek. The restoration project involves removal of a portion of a concrete creek culvert and creation of a longer rock rip-rap chute structure. The restoration project is designed to reduce erosional processes at the existing culvert that have caused stream bank erosion and bank failure at that site.

As generally reported in the Draft Initial Study for the Matadero Creek Restoration and Bank Stabilization Project (WRA 2015), the primary effects of the restoration project would occur during its short-term construction phase. Construction phase effects of small projects like the restoration activity are generally limited to the immediate vicinity of the activity. The short-term construction impacts of the restoration project as identified in the IS/MND for the restoration project include temporary impacts to views to the restoration site from a local road; generation of

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air quality emissions; impacts on biological resources including special-status/protected species, sensitive habitat (wetlands and waterways), and tree removal; potential disturbance of unknown cultural resources; soil erosion and related water quality degradation; construction equipment noise; and slight delays on roadways due to construction traffic (no level of service performance standards would be exceeded). All of the potential construction impacts are mitigated to less than significant. The cumulative analysis in the IS/MND notes that “due to the limited scope of direct physical impacts to the environment associated with construction, the project’s impacts are project-specific in nature [...]. Consequently, the project along with other cumulative projects will create a less than significant cumulative impact with respect to all environmental issues.” (WRA 2015, p. 66). The referenced cumulative projects are not identified.

Because the restoration project impacts are limited to its construction phase, only the construction phase effects of the proposed project have potential to combine with the restoration project effects to create cumulatively considerable impacts during the construction phase. Further, such effects are only possible if the construction periods for both projects overlap. The IS/MND states that the restoration project would take about two months to construct and that pending permitting clearances, construction is tentatively planned for July to August of 2016. A tentative August start date has been confirmed by the Town. A specific construction start date for the proposed project has not yet been identified. Prior to initiating construction, a number of actions must be taken. The proposed project must first be approved by the Town. Final development plans would then need to be prepared and approved. In addition, a range of project conditions and mitigations would need to be met and implemented. Given these factors, it is highly unlikely that construction would begin any time before late spring/early summer of 2017. Hence, it is also highly unlikely that the construction periods for the two projects would overlap, in which case the proposed project would have no potential to result in construction phase cumulative impacts.

Construction phase impacts of the proposed project are identified in the IS/MND and are similar to those identified in the restoration project IS/MND. Like construction effects described for the restoration project, the construction effects of the proposed project would largely be limited to the project site and its immediate surroundings. Its construction impacts are reduced to less than through compliance with regulatory standards and mitigation measures described in the IS/MND. Consequently, the proposed project effects would be less than cumulatively considerable even if construction of the two projects were to overlap.

Because construction impacts are localized, even if the two projects were under construction at the same time, it is highly unlikely that effects of the proposed project would combine with those of the restoration project to create a cumulatively considerable impact.

Fencing and Wildlife. Regarding existing property line fencing and the potential for the proposed project to result in cumulatively considerable impacts on wildlife movement, please refer to the discussion in Sections II.A, II.B, and IV.E above. The proposed project will not have a cumulatively considerable impact on wildlife movement because the two most important wildlife corridors on the site will be maintained. The proposed project will be conditioned to require that all new fencing in the open space easement area between lots 5-9 and along the western boundary of lots 5-9 is wildlife friendly.

DISCUSSION OF ISSUES RAISED IN THE WELCH LETTER

STIRLING SUBDIVISION – SHUTE/WELCH RESPONSE LETTERS

Consistent with CEQA Guidelines Section 15063(d), the IS/MND adequately identifies the environmental setting, including a description of the Matadero Creek. The IS/MND describes the Matadero Creek as originating upstream of the project site, draining to the Mayfield Slough and ultimately into the San Francisco Bay, with slopes of 30 percent or more in some areas. Figure 2 in the IS/MND is an aerial photograph showing existing conditions on and adjacent to the project site. Figure 3A and 3B show representative conditions within the site. Further details are described above in Sections IV.C.1, IV.C.2 and IV.C.3. There is no evidence that the proposed project would exacerbate existing downstream erosion of the bed or banks of Matadero Creek.

The applicant’s SWCP has been reviewed by the Town’s independent consulting environmental engineer for consistency with C.3 requirements. The proposed project qualifies as one for which the rate of storm water discharge from the site under post-project conditions is not permitted to exceed pre-project conditions. The SWCP preparation and approval process includes a requirement to model pre-project storm water conditions and compare them to post-project conditions (with implementation of SWCP control measures) to assure that this requirement is met. The modeling conducted for this purpose was reviewed by the Town’s independent consultant and found to be acceptable. The detention basin is a control measure included in the SWCP. Its operation is one component of the overall SWCP control measure system. As noted above, the SWCP system has been reviewed to verify that the post-project storm water runoff rate to Matadero Creek will not exceed pre-project rates. The on-site Matadero Creek tributary will be preserved as part of the open space easement. Accordingly, Matadero Creek would not be altered as part of the project and no impact on flood conditions from alteration of the stream or water course would occur.

Chapter 12 of the IS/MND describes the existing noise environment and the temporary noise increase that would accompany construction of the Project. The IS/MND finds impacts from project noise to be less than significant because residential use activities will not result in a significant increase in ambient noise levels relative to existing conditions in the project area. On- site residential use activities are not typical sources of permanent increases in ambient noise levels. Project compliance with regulatory requirements, including the Town’s applicable allowable noise standards set forth in the Town’s municipal code, is sufficient to reduce any temporary construction noise to less than significant. Although compliance with these Town municipal code requirements is mandatory by law and the applicant has stated in the record that the project has always assumed full compliance with the Town’s code, the Town will condition approval of the project on the applicant’s compliance with the limitations provided in the Town’s noise standards, as referenced in the IS/MND (Attachment J). By ensuring full compliance with the Town’s allowable noise standards, any temporary noise from construction activities of the proposed project will be minimized to less than significant levels.

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