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HomeMy WebLinkAbout09-20-2016 Item 08 Laguna Lake Dredging and Sediment Management Project Meeting Date: 9/20/2016 FROM: Derek Johnson, Assistant City Manager Prepared By: Robert A. Hill, Natural Resources Manager SUBJECT: LAGUNA LAKE DREDGING AND SEDIMENT MANAGEMENT PROJECT - PREFERRED PROJECT ALTERNATIVE SELECTION RECOMMENDATION Receive and file the Preliminary Dredging Report (the “PDR”) prepared by MNS Engineers, Inc. and, as further described in the PDR, direct staff to proceed with further analysis and further recommendations related to the following preferred project alternative: 1. Use of hydraulic or cyclonic dredging equipment as the dredging technology; and 2. Removal of 50,000 cubic yards of sediment from the Laguna Lake as the dredging project option; and 3. Mechanical dewatering at Laguna Lake Park as the dewatering location and method; and 4. Off-site disposal at Cold Canyon Landfill as the sediment deposition location and facility; and 5. Creek bank restoration and installation of a sediment basin at Laguna Lake Golf Course along Prefumo Creek, as well as shoreline restoration at the lake itself, as short-term sediment management strategies. REPORT-IN-BRIEF In January 2016, the City retained the firm MNS Engineers (“MNS”) to assist the City with the work plan that was adopted by the City Council as part of the “Other Important Council Objectives” associated with the 2015-17 Financial Plan. The first phase of the work prepared by MNS, in consultation with staff, includes development of the Preliminary Dredging Report (“PDR”). The PDR documents eleven significant key project elements. The fiscal impacts associated with the Laguna Lake Dredging and Sediment Management Project, as recommended, are substantial. Staff anticipates that the total project cost based on staff’s recommended preferred alternative is estimated to be $10-12 million. Following the City Council’s selection of the preferred project alternative, it is expected that staff and the City’s consultant team will analyze the costs and the benefits that will accrue to the community, to neighboring property owners and residents, and to the natural ecosystems found within Laguna Lake and its surroundings, and complete the required California Environmental Quality Act (CEQA) analysis. As overall project costs and project feasibility are further refined based on subsequent engineering, environmental review, and evaluation of the potential for land-based financing, staff will return to Council for additional actions necessary to move the project to “shovel ready” status. 8 Packet Pg. 77 DISCUSSION Background The City of San Luis Obispo owns the 344 -acre Laguna Lake Natural Reserve (the “Reserve”) that includes most of the lake itself, portions of Prefumo Creek and its outlet into the lake, and adjacent upland areas. The City Council adopted the Laguna Lake Natural Reserve Conservation Plan (“Conservation Plan”) on July 15, 2014 to guide future management of the Reserve by offering a framework for conservation, restoration, recovery, and scenic recreational use. Laguna Lake is primarily a naturally occurring lake, although the lake and its watersheds have been altered and manipulated, to include the re-routing of Prefumo Creek into the lake in the early 1960s to help facilitate the 1961 Master Plan for Laguna Lake and the construction of Tract 279 along Oceanaire. This has resulted in increased sediment deposition rates. Recent bathymetric surveys indicate accelerated changes in lake depth and morphology resulting in decreased water quality and aquatic habitat functions, as well as diminished aesthetic and recreational values associated with the lake. As a result, dredging and sediment management strategies are among the primary recommendations of the Conservation Plan. The City’s Financial Plan for 2015-17 identifies implementation of the Conservation Plan as an “Other Important Council Objective” and includes a work plan that contains all of the necessary steps to make a dredging and sediment management project “shovel ready”. In January 2016, the City retained the firm MNS Engineers (“MNS”) to assist the City with the work plan that was adopted by the City Council. MNS is the prime contractor for a multi-disciplinary team to complete the following main tasks: 1.) Prepare Design Plans and Engineering Specifications; 2.) Environmental Studies and Project Permitting; and 3.) Public Outreach and Financing Options. Preliminary Dredging Report The first phase of the work prepared by MNS, in consultation with staff, includes development of the Preliminary Dredging Report (“PDR”). The PDR documents 11 key project elements: 1. A review of the current status of the lake, previous studies, and management documents; 2. New geotechnical and water quality testing data; 3. New biological and cultural resource assessments; 4. A review of applicable dredging technologies and approaches; 5. Development of dredging alternatives; 6. Recommendations for deposition and disposal of sediments; 7. A preferred alternative recommendation; 8. Dredging operations recommendations; 9. Recommendations for future sediment management; 10. An overview of additional project amenities and project enhancement opportunities; and 11. An analysis of project funding options. Of the project elements described in the PDR, those that are especially pertinent to the recommendations set forth in this Council Agenda Report are further detailed below. 8 Packet Pg. 78 Geotechnical Investigation and Sediment Characterization A geotechnical investigation and analysis was completed in the spring of 2016 by Leighton Group, Inc., to characterize lake bed deposits, identify any contaminants present in lake sediments, determine the slope stability of the existing lake shore banks, and provide dredging recommendations based on the findings of their investigation. The complete geotechnical report documenting the geotechnical investigation and analysis is provided in the PDR. The subsurface investigation included five surface soil samples and eleven vibracore samples. For each core, samples were taken at discrete intervals, three per core, in order to enable detailed sediment chemistry testing. The results of the geotechnical investigation indicated that the lakebed materials are largely silty to fat clays (CH) interlayered with lean clay (CL) and inorganic silt (MH) throughout the lake and within the principal proposed dredging areas. There is limited sand present in thin surface layers within the delta formed at the mouth of Prefumo Creek. The clays generally transition from a soft oxidized clay to a stiff clay with little to no air voids with increasing depth. Sediment samples collected were analyzed for metal and nitrate and phosphate content. In addition, modified elutriate tests were performed on sediment collected from Laguna Lake. Sediment chemistry testing detected nickel, Chromium 3 (Cr+3) and Chromium 6 (Cr+6) in the areas surrounding the lake as well as concentrations in the lake sediment. The detectable levels of chromium and nickel in the soil samples are naturally-occurring and the result of outcrops of serpentine rock located in the surrounding watersheds that drain to the lake. Detected levels of nickel and Chromium (Cr+6) are below the EPA dictated National Action Levels (NALs). However, at some locations, samples exceed the US EPA Region 9 Regional Screening Level (RSL) for a residential setting. Soil chemistry is typical of the general region, with no contamination noted from man-made sources such as Total Petroleum Hydrocarbons (TPH), Volatile or Semi-Volatile Organic Compounds (VOC or SVOC), or Pesticides. Dredging Technology There are three main types of appropriate dredging techniques associated with small inland water bodies: 1) mechanical, 2) hydraulic, and 3) cyclonic. Mechanical dredging involves the physical excavation of sediment material using conventional earth moving equipment, such as a backhoe, or specialized excavation equipment, such as a clam shell excavator or draglines. The advantages of mechanical dredging are that water is not required for dredging operations, little water is used in the dredging process and excavated soil material maintains its in-situ density. Disadvantages associated with mechanical dredging are that the excavation is not as precise as other methods and the reach distance of mechanical equipment can limit excavation extents or require additional logistics; this is especially true given the soil characteristics at Laguna Lake. Hydraulic dredging is performed by using sucti on to pump sediments to the shore in a slurry state. The advantages of hydraulic dredging are dredging precision, flexibility of reach, and access to sediments. The chief disadvantages of hydraulic dredging are the required water use associated with making the slurry, down times to repair and maintain piping, and the drying time required for slurry dredged sediment. With cutting head attachments hydraulic dredging can also 8 Packet Pg. 79 increase the turbidity of the water body being dredged. Turbidity issues associated with hydraulic dredging can be mitigated through the use of a turbidity curtain. Cyclonic dredging is an emerging hydraulic dredging technology that generates a vortex to transport sediments. The vortex reduces friction between transported sediments and the transmission pipe resulting in higher excavation rates, increased percent age of solids in slurry dredged sediment, less pipe break downs, and a longer pipe transport range. Dewatering processes would limit typical excavation rates of both conventional and cyclonic dredging operations. However, the increased percent solids of slurry material achieved by cyclonic dredging would accelerate the dewatering process, which could translate to less onsite space used for dewatering and an increased dredging rate. Even with cutting head attachments cyclonic dredging reportedly does not increase the turbidity of the water body being dredged. The following table provides a summary of different aspects of the three dredging techniques: Color Key Poor Fair Fair Good Dredging Technology Options Mechanical Hydraulic Cyclonic Environmental Impact Medium – Low Turbidity Medium Turbidity, Some Water Level Impact No Turbidity, Slight Water Level Impact Works Offshore With barge or constructed land bridge Yes Yes Excavation Rate (CY/Hr) NOte 70-100 200-400 900-1000 Percent Solids In Situ 10-20% Up to 80% Daily Maintenance (Hrs/Day) 1 2 <1 Minimum Operational Depth None 3 feet < 3 feet Accuracy Rough grading Precise Precise Soil Transport via Pipeline No Yes Yes Pipeline Transport Range N/A 3,000 feet >5,000 feet The recommendation is to select hydraulic or cyclonic dredging as a combined option in the plan specifications giving the City the opportunity to better understand the competitive bidding environment for a project that utilizes either of these options. This is because cyclonic dredging is relatively new technology and not all prospective contractors have access to it. 8 Packet Pg. 80 Dredging Priority Areas Three Priority Areas were identified by staff and the engineering consultant as part of the PDR and ranked in order of importance. These areas are outlined in the exhibit below, and are also shown as Figure 8 of the PDR and in the Map Set that is Attachment A. The area encompassing the northwest inlet, peninsula inlet, and transition into Center Lake was not considered for the proposed dredging project. The northwest inlet and peninsula inlet areas have high environmental and biological significance and should not be disturbed. The area between the northwest and peninsula inlets and Center Lake experiences a low rate of sedimentation because of the topography and characteristics of these drainages and the ability of the marsh wetlands to capture the sediment. Dredging Project Alternatives Alternative 1 addresses Priority Area 1, the area identified as having the highest sedimentation rate in Laguna Lake. Dredging in this area has the greatest impact on the lake’s ability to capture sediment passing through Prefumo Creek and Prefumo Arm. This elevation was selected to address the alluvial fan in Priority Area 1 but also to connect the northwest end of the lake to Center Lake with a smooth transition. The total project hard costs would be roughly $5.26 million with dewatering using onsite sedimentation ponds or $6.34 million with mechanical dewatering. The physical characteristics of Alternative 1 are shown in the table, below: 8 Packet Pg. 81 Characteristic Value Target Priority Area(s) 1 Dredged Volume 36,500 CY Dredged Area 15.95 acres Max. Existing Elevation 119.2 Finished Elevation 114.0 Max. Dredging Depth 5.2 feet Lake Capacity Increase 22.6 AF A range is proposed for Alternative 2 in order to provide the opportunity to select a point within the range that best satisfies the goals of this dredging project within potentially available financing. The low end of the range is anticipated to cost approximately $6.95 million with dewatering basins and $8.68 million using mechanical dewatering practices. The high end of the range for Alternative 2 is anticipated to cost approximately $11.32 million with the sedimentation pond method for dewatering and $14.55 million using mechanical dewatering. By addressing Priority Areas 1 and 2, Alternative 2 provides a greater ability to remove sediment than Alternative 1. Alternative 2 also increases the lake depth over a larger area, which provides both environmental and recreational benefits. Expanding the dredging area towards the boat launch area provides access to deeper water for kayakers, canoers, and other recreational boaters. A wider, deeper lake bed also provides aquatic wildlife with a larger habitat and overall healthier ecosystem. The physical characteristics of Alternative 2 are shown in the table, below: Characteristic Value Alternative 2-Min Range Alternative 2-Max Range Target Priority Area(s) 1 & 2 1 & 2 Dredged Volume 50,000 CY 85,000 CY Dredged Area 21.40 acres 31.00 acres Max. Existing Elevation 119.2 ft. asl 119.2 ft. asl Finished Elevation 113.75 ft. asl 113.25 ft. asl Max. Dredging Depth 5.4 feet 5.9 feet Lake Capacity Increase 31.0 AF 52.7 AF Alternative 3 represents the alternative in which all three priority areas are dredged. Alternative 3 would cost roughly $21.6 million with the sedimentation pond method for dewatering and $27.3 million using mechanical dewatering. The physical characteristics of Alternative 3 are shown in the table, below: 8 Packet Pg. 82 Characteristic Value Target Priority Area(s) 1, 2, &3 Dredged Volume 167,000 CY Dredged Area 35.37 acres Max. Existing Elevation 117.6 Finished Elevation 111.5 Max. Dredging Depth 6.1 feet Lake Capacity Increase 103.5 AF In sum, Alternative 1 represents the minimum economically feasible project in consideration of mobilization costs and achieving the primary project goal of attending to the accumulated sediment at the outlet of Prefumo Creek. Alternative 3 represents a project that would result in lake depths of approximately 9 feet when full through the Center Lake and Southeast Arm, which is consistent with prior Council direction in 2010; however, at an expected cost of over $20 million, this alternative is likely to be financially infeasible. Alternative 2 provides a project that achieves the primary project goal of attending to the accumulated sediment at the outlet of Prefumo Creek, while also providing longer-lasting benefits and additional aesthetic and recreational benefits. In consideration of these expected benefits, on balance with anticipated financial feasibility, a project in the low range of Alternative 2 that will remove 50,000 cubic yards of sediment from the lake is therefore recommended as the preferred dredging option. Dewatering Dredged sediment can be mechanically dewatered, dewatered using dewatering basins, or dewatered by a combination of the two methods. Dewatering basins require adequate onsite space; in the case of the Laguna Lake project 6-8 acres would be necessary. A typical dewatering basin system has a sequence of at least three basins. Dredge slurry is pumped into the dewatering basin at the top of the sequence until that dewatering basin is full. The material is then allowed time to settle. Optionally, additives may be used to decrease the settling time. Clarified water is then pumped or syphoned off the top of the dewatering basin and sent to the second and third basins in the series for additional clarification. The basin retention time required to meet turbidity requirements identified in the permitting process is also another factor that will affect production schedule. Locating adequate space for settlement basins will likely be challenging on City owned property on the north side of the Lake within the park due to other ongoing uses. Mechanical dewatering allows for faster return of water used in dredging operations but is generally more expensive. However, mechanical dewatering can be accomplished with less onsite space; in this case 3-4 acres. Mechanical dewatering methods can include belt presses, centrifugal sludge handlers, screw presses, or heat, among others. Commercial sludge dryers of various t ypes are commonly used due to their ability to incorporate return water treatment processes. 8 Packet Pg. 83 Due to space considerations in the park and the goal of minimizing disruptions in the park, timing dewatering with the pace of dredging production, as well as the opportunity to return treated water back into the lake quickly, mechanical dewatering is recommended. The proposed dewatering area is delineated in Figure 18 in the PDR and in the Map Set that is Attachment A. This option was endorsed by the Parks and Recreation Commission at their meeting on August 3, 2016 (Attachment B). A summary of dredging and dewatering project options is depicted in the table below: Proposed Alternative Priority Areas Dredged Volume (CY) Total Cost Cost Per CY Alternative 1A 1 36,500 $5.3 million $144.1 Alternative 1B 1 36,500 $6.3 million $173.8 Mechanical Alternative 1 1 36,500 $6.1 million $165.7 Alternative 2A- Min Range 1 & 2 50,000 $7 million $138.9 Alternative 2B- Min Range 1 & 2 50,000 $8.7 million $173.7 Mechanical Alternative 2- Min Range 1 & 2 50,000 $7.4 million $148.6 Alternative 2A- Max Range 1 & 2 85,000 $11.3 million $133.2 Alternative 2B- Max Range 1 & 2 85,000 $14.6 million $171.2 Mechanical Alternative 2- Max Ranage 1 & 2 85,000 $12.4 million $145.5 Alternative 3A 1, 2, &3 167,000 $21.6 million $129.1 Alternative 3B 1, 2, & 3 167,000 $27.3 million $163.5 Mechanical Alternative 3 1, 2, & 3 167,000 $23.2 million $139.1 A – Hydraulic Dredging with Dewatering Basin B – Hydraulic Dredging with Mechanical Dewatering Sediment Deposition Several sites were evaluated for the deposition of dredged material. To minimize hauling costs, only sites within 10 linear miles of Laguna Lake were considered. Due to the silty, heavy clay nature of the sediment, few beneficial uses exist for the dredged material. However, all potential sites within the 10-mile radius were evaluated, including the Laguna Lake Natural Reserve and Laguna Lake Park, privately-owned property adjacent to the Reserve, Cold Canyon Landfill, the Chevron Tank Farm, and Price Canyon oil field. 8 Packet Pg. 84 The area directly to the east and northeast of Laguna Lake is part of the Laguna Lake Natural Reserve and the Laguna Lake Park, both City-owned properties with open land available for sediment deposition. Various areas within these properties were identified and evaluated for potential sediment deposition. However, an on-site deposition strategy proved to be challenging for three primary reasons: 1.) both prior and current botanical surveys (Keil, 1996; Terra Verde, 2014; Rincon 2016) documented the presence of numerous rare, special-status plant species including the adobe sanicle (sanicula maritima) which would require an Incidental Take Permit from California Department of Fish and Wildlife prior to any site disturbance under the California Endangered Species Act; 2.) the geotechnical and chemical properties of the sediment both in the lake and in the soil at the areas identified for potential deposition, as discussed above under the Geotechnical Investigation sub-heading; and 3.) the total volumes of sediment under consideration, if placed on-site, would result in substantial areas of the Reserve and Park being disturbed during the course of dredging operations that would likely require most, if not all, of the Reserve and Park to be closed during construction, while ongoing restoration and monitoring efforts would continue for many years following the physical implementation of the dredging project. For these reasons, on-site deposition should not be considered. Various local ranch properties were also identified and evaluated as potential deposition sites for the dredged sediment. Several of these properties are adjacent to Laguna Lake and these sites could be accessed through public roads or roads created through private property. Several other nearby and regional locations were also identified. However, large portions of these sites lie within the 100-year flood plain, according to the Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map (FIRM), which limits the available area for deposition, while the geotechnical and chemical properties of the dredged sediment would also be problematic for potential deposition on private properties. Currently, the only plausible and feasible deposition site of the dredged sediment is the Cold Canyon Landfill (Cold Canyon), which is a Class III municipal solid waste disposal facility and is already permitted by the appropriate regulatory agencies for accepting waste materials. It is located seven miles to the southeast of the City along Highway 227. A meeting was conducted on May 26, 2016, between MNS, the City, and Cold Canyon representatives to discuss several criteria regarding the disposal of dredged sediment. Under its current permit, the dredged sediment meets Cold Canyon acceptance criteria and the facility can receive up to 1,200 tons of solid waste per day. Accounting for the Landfill’s average daily intake from municipal trash collection, Cold Canyon can receive approximately 600 tons of sediment per day. At an estimated unit weight of 125 pounds per cubic foot (lb/ft3), 600 tons equals roughly 350 CY of sediment, which approaches the estimated daily dredging production rate. Cold Canyon plans to open a new landfill cell on its property in the coming months, and under a new permit, it could receive a total of 1,600 tons of solid waste per day. The increased capacity could allow for a higher sediment disposal rate. For planning and cost-estimating purposes, Cold Canyon suggests a tipping fee of $20 per ton ($33.75/CY). This rate is lower than the tipping fee for private entities, although further negotiations would be made before a contract is finalized. When finalized, the contract would be active for one year. Cold Canyon also imposes a moisture content limit of 50% for the sediment. The quality of the sediment has been initially accepted; however, Cold Canyon requires a soil 8 Packet Pg. 85 sample report for every 1,000 CY of sediment disposed of at the Landfill, with soil samples valid for up to one year before disposal. Sediment Reduction There are two areas within and tangent to Laguna Lake that are actively contributing sediment to the lake environment due to eroded and unstable conditions. Sections along Prefumo Creek within the upstream extent of the Laguna Lake Golf Course have become over-steepened and present near vertical banks where this section of creek leaves the original, historic alignment of Prefumo Creek and enters the re-aligned and straightened portion of Prefumo Creek that was completed in the early 1960s. At this location, the creek appears to be re-gaining sinuosity and a natural “angle of repose” but in doing so has caused significant erosion. Stabilization measures should be evaluated on a case by case basis through this system by the design engineer and biologist to insure desired outcomes due to the dynamic nature of creek systems and the propensity of one action to cause another action further downstream. Areas of erosion and shoreline sloughing exist along the northeast shore of the lake near the boat launch/ramp area, access road and parking lot. In addition, the shoreline path has eroded and parts of the path and road have failed due to wave action associated with the predominant westerly winds frequently encountered at the lake. The design recommendations that govern selection of shoreline erosion protection are further described in the PDR and include: 1. Indirect or vegetative methods preferred over structural methods such as is vegetated rock slope protection ("VRSP"), as may be necessary; 2. Protect and conserve stream bank and shoreline features with the potential to attenuate impaired runoff; and 3. Plan and manage activities within the water bodies adjacent to shorelines and along the shoreline to limit erosion. Over the longer-term, the Laguna Lake Natural Reserve Conservation Plan also recommended seeking voluntary conservation easement agreements in the upper watersheds that drain to the lake in order to maintain low-intensity land uses in these areas. Staff will continue to track such opportunities through the City’s Greenbelt Protection Program, with recognition that protection of the watersheds associated with Laguna Lake would represent an additional, substantive benefit relative to the priority-setting of land conservation opportunities throughout the Greenbelt. Sediment Management Prior studies indicate that the Prefumo Creek watershed deposits an average annual load of 8,000 CY of coarse sediment in the Prefumo Inlet and 3,900 CY of finer sediment in the Center Lake portion of Laguna Lake. In total, an estimated 11,900 CY of sediment is carried from the Prefumo Canyon watershed and deposited in the Prefumo Inlet and Center Lake per year. These deposits are detrimental to the water quality, fish habitat, recreational use, and hydraulic capacity of Laguna Lake. It is recommended that sediment from the Prefumo Creek watershed be collected and removed to 8 Packet Pg. 86 the extent possible before they are deposited in the lake since the sediment deposits spread out over a larger area. Soil deposits from the Prefumo Creek watershed also become more sorted and have the potential to mix with contaminants, making the material excavated from the lake less feasible for offsite placement. In addition to collecting and removing sediment in the Prefumo Inlet downstream of Los Osos Valley Road, it is recommended that a new sediment collection pond be created in the area immediately upstream of Los Osos Valley Road. To capture the majority of the total average annual sediment load of 11,900 CY, a four–feet-deep pond would require about a two-acre footprint. The exact location of the placement of this pond would be identified through additional analysis. The portion of the Prefumo Inlet located upstream of Los Osos Valley Road is part of Laguna Lake golf course. The City could easily access the site to regularly remove sediment deposits on a periodic basis and no land acquisition or easements would be required. This area is also less environmentally sensitive than the portion of the Prefumo Inlet located downstream of Los Osos Valley Road. The site that has been identified would be located in an area of regular play within the golf course. The annual cost of regularly removing sediment from the basin would be much less than the costs to remove the same sediment from Laguna Lake. Should the Council support intercepting as much sediment as is reasonably possible, an estimate of the annual operating costs to remove sediment and debris from the basin will be provided to the City Council before making a final decision on this aspect of the project. Additional Project Amenities and Enhancement Opportunities One of the major findings and recommendations of the 2014 Laguna Lake Natural Reserve Conservation Plan was to increase access and use of the lake as a valued passive recreational amenity for boating, fishing, hiking, and bird watching1. Potential projects identified for further detailed evaluation, design, and environmental review pursuant to the Conservation Plan include: 1. Improved signs and kiosks (currently underway pursuant to the Open Space Major City Goal work plan); 2. An accessible walking path along the lake shoreline within the Reserve (also underway); 3. A raised boardwalk along the peninsula feature of the lake; 4. Improved boat launch and parking area; 5. Viewing platforms at two locations on the south side of the lake at Priolo-Martin Park and adjacent to Laguna Middle School between the cul-de-sacs at the end of Vista Del Lago and Vista Del Collados; and 6. Migratory fish passage improvements at the Prefumo Creek culverts below Madonna and Los Osos Valley Roads, as well as potentially improved flood attenuation capacity and surface elevation management through alterations of the Madonna Road culverts. 7. Future recycled water line extension to provide a base amount of water in the lake during extreme drought events for dust control, weedy vegetation control, and to provide watering opportunities for wildlife. Option items 1-5, above, were endorsed by the Parks and Recreation Commission at their 1 “Throughout the planning process, community members were consistent in stating their preference that the lake continue to be maintained to support recreational uses, and that the City should do more to increase access and use of the Reserve as an attractive amenity” (p. 5). 8 Packet Pg. 87 meeting on August 3, 2016 (Attachment B). Project Funding and Financing Recommendations The recommended activities to be funded include the primary dredging and sediment management components of the project, as well as ongoing operations and maintenance associated with and the lake and sediment management aspects described above. These activities have multiple benefits including drainage and flood control, recreation, water quality, habitat restoration, and aesthetic benefits. The expected project beneficiaries include residents and visitors of the City of San Luis Obispo, as well as property owners that are proximate to Laguna Lake. The benefits accrued to these parties must be allocated and the costs should be equitably assessed as a matter of sound public policy. There are several mechanisms to levy the costs of allocated benefits. A preliminary funding and financing plan was prepared and is included with the PDR. Numerous grant opportunities were evaluated, as well as low-interest loans, City provided funding sources, and land-based financing options. The recommended project, in its totality, is comprised of a diverse combination of activities that would provide both community-wide, and localized benefits. However, the initial and ongoing cost of accomplishing the project is significant. Accordingly, a broad funding strategy is necessary for the project to be successful given the range and scope of other pressing capital and maintenance projects needed throughout the City. In order to provide the necessary funding to implement the various project elements, the following recommendations are presented for consideration: 1. Monitor potential State and Federal grant programs on an ongoing basis. As each potential project element is developed and approved, review the applicable programs for the feasibility of a successful application, level of potential funding, and funding schedule of the program. Because of the level of funding required and the broad range of benefits provided, the highest priority should be given to grant programs that focus on water quality, habitat restoration, non-point source management, and recreational development. At this time, State of California grant funding has been identified for several of the project’s sediment management and amenity enhancement features based on staff’s prior experience. These are: a) Peninsula Boardwalk - California Department of Parks and Recreation, Habitat Conservation Fund Trails Program b) Boat Launch and Parking Area – California Department of Boating and Waterways c) Creek and Shoreline Stabilization Projects, Fish Passage and Flood Control Improvements – California Wildlife Conservation Board 8 Packet Pg. 88 2. Pursue land-based financing. Formation of a benefit-assessment district would provide a vehicle for sediment removal and ongoing maintenance funding that would be allocated based on the level of localized benefit that the project provides. Multiple districts or zones may be necessary to separate the level of benefits anticipated in various areas, although the allocation between these types of benefits cannot be determined until the project benefits are quantified and addressed in the Engineer’s Report that would support district formation. However, in the event that the Engineer’s Report cannot provide quantifiable evidence of specific property benefit, a Community Facilities District (CFD) is recommended to be pursued. A CFD has a higher threshold for successful formation, but does not require an Engineer’s Report. The potential for land-based financing was first included in Council direction set forth in 2010. Following the prospective selection of the preferred project as contemplated in this Council Agenda Report, staff will work with the consultant team to determine the feasibility of land-based financing options through public outreach with potentially affected property owners and through public opinion research. As above, the use of a benefit assessment district (if selected) requires the preparation of an Engineer’s Report as a necessary condition precedent to district formation. This report would describe the boundaries of the district and zones, the activities to be funded, the basis for allocating costs, and the cost to each parcel. The formation of a benefit assessment district requires voter approval. 3. Evaluate the level of financial contribution and commitment from the City’s General Fund. The project is expected to accrue both community-wide benefits and specific benefits to areas proximate to the lake. In support of the community-wide benefits, the City should evaluate the level of financial contribution and commitment it is willing to make with its General Fund through its normal, customary financial plan priority-setting process. 4. Utilize an Infrastructure State Revolving Fund (ISRF) low-interest loan. The California Infrastructure and Economic Development Bank (I-Bank) provides low interest loans for eligible projects, such as: a) Drainage, Water Supply, and Flood Control including ditches, levees, pumps, pipes, as well as the acquisition, improvement, maintenance, and management of flood plain areas and all equipment used in the associated maintenance and operation; b) Environmental Mitigation Measures including required construction or modification of public infrastructure, and purchase and installation of pollution control and noise abatement equipment; and c) Parks and recreational facilities. Financing amounts range from $50,000 to $25,000,000 per project with a maximum 30- year term. The interest rate for each loan is set at the time the loan is approved and is based on the Interest Rate Benchmark and Interest Rate Adjustments. For loans equal or 8 Packet Pg. 89 greater to $250,000, a one-time origination fee of $10,000 or 1% of the original loan amount, whichever is greater is due at closing. The City would need to pledge a piece of City-owned real property of equal or greater value as security for the loan. A low-interest credit facility provided through ISRF would be a key element of the overall funding and financing strategy as a means of providing the up-front capital necessary to undertake the project, while revenues streams from potential land-based financing and the City’s General Fund would be used for debt service. Staff met with senior I-Bank representatives in Sacramento in July 2016 to ensure that the proposed project meets with their eligibility and underwriting requirements, as well as to ensure that the City would have adequate credit capacity for this project as well as other future capital infrastructure projects. Based on this meeting and subsequent I-Bank review, the City has been invited to apply. CONCURRENCES The Parks and Recreation and Public Works Departments have provided their concurrence for the recommendations set forth in this Council Agenda Report. ENVIRONMENTAL REVIEW There is no environmental review required to provide direction on the recommended preferred project options under the California Environmental Quality Act (CEQA). Once the preferred alternative is selected, however, the City and its consultant team will be able to develop and provide a detailed project description upon which the environmental review process will be based. The City Council’s direction on the preferred project options is not intended to preclude the formal alternatives analysis that would be required under CEQA if a full Environmental Impact Report (EIR) is determined to be the appropriate environmental document. In addition, the project will require review and regulatory permits from numerous other agencies in order to be lawfully conducted, potentially including: California Department of Fish and Wildlife; Regional Water Quality Control Board; Air Pollution Control District; U.S. Fish and Wildlife Service; and, the National Oceanic and Atmospheric Administration (NOAA) Fisheries Division. FISCAL IMPACT The fiscal impacts associated with the Laguna Lake Dredging and Sediment Management Project, as recommended, are substantial. Staff anticipates that the total recommended project cost is between $10-12 million. This estimate is based on known hard costs associated with dredging production, dewatering, and sediment disposal as described above; however, exact regulatory permit requirements and mitigation measures associated with the project are not yet known (although mitigation costs as a percentage of total project costs are included for estimating purposes, see Appendix F of the PDR), nor are exact costs and prospective grant awards associated with project amenities and enhancements yet known. 8 Packet Pg. 90 Following the City Council’s feedback on the preferred project alternative, it is expected that staff will return with more detailed costs and articulation of the benefits that will accrue to the community, to neighboring property owners and residents, and to the natural ecosystems found within Laguna Lake and its surroundings. As overall project costs and project feasibility are further refined based on subsequent engineering, environmental review, and evaluation of the potential for land-based financing, staff will return to Council for additional discussion and subsequent action steps necessary to move the project to “shovel ready” status. ALTERNATIVES The City Council could: 1. Request additional information or analysis from staff. 2. Continue consideration of the recommendation with direction to staff on necessary changes. 3. Select some of the recommended options, while selecting alternatives for other options. Because there are five different preferred project elements set forth in the recommendation, and there are various aspects to consider within each project element, there are many possible permutations from which project choices could be selected. AVAILABLE FOR REVIEW IN THE COUNCIL OFFICE 1. Master Plan Laguna Lake Park (1961) 2. Laguna Lake Management Program (1982) 3. Laguna Lake Technical Appendix (1982) 4. Laguna Lake Park Master Plan (1993) 5. Council Agenda Report (2009) 6. Council Agenda Report (2010) 7. Laguna Lake Natural Reserve Conservation Plan (2014) 8. Preliminary Dredging Report (2016) These documents are also available for review on the City’s website using the following link: http://www.slocity.org/government/department-directory/city-administration/natural- resources/laguna-lake Attachments: a - Laguna Lake Dredging and Sediment Management - Map Set b - Parks and Recreation Commission Draft Minutes of 8-3-16 c - Council Reading File 8 Packet Pg. 91 8.a Packet Pg. 92 Attachment: a - Laguna Lake Dredging and Sediment Management - Map Set (1447 : Laguna Lake Dredging and Sediment Project - Preferred 8.a Packet Pg. 93 Attachment: a - Laguna Lake Dredging and Sediment Management - Map Set (1447 : Laguna Lake Dredging and Sediment Project - Preferred 8.a Packet Pg. 94 Attachment: a - Laguna Lake Dredging and Sediment Management - Map Set (1447 : Laguna Lake Dredging and Sediment Project - Preferred 8.a Packet Pg. 95 Attachment: a - Laguna Lake Dredging and Sediment Management - Map Set (1447 : Laguna Lake Dredging and Sediment Project - Preferred 8.a Packet Pg. 96 Attachment: a - Laguna Lake Dredging and Sediment Management - Map Set (1447 : Laguna Lake Dredging and Sediment Project - Preferred 8.a Packet Pg. 97 Attachment: a - Laguna Lake Dredging and Sediment Management - Map Set (1447 : Laguna Lake Dredging and Sediment Project - Preferred 8.a Packet Pg. 98 Attachment: a - Laguna Lake Dredging and Sediment Management - Map Set (1447 : Laguna Lake Dredging and Sediment Project - Preferred 8.a Packet Pg. 99 Attachment: a - Laguna Lake Dredging and Sediment Management - Map Set (1447 : Laguna Lake Dredging and Sediment Project - Preferred 8.a Packet Pg. 100 Attachment: a - Laguna Lake Dredging and Sediment Management - Map Set (1447 : Laguna Lake Dredging and Sediment Project - Preferred Minutes - DRAFT PARKS AND RECREATION COMMISSION 3 August, 2016 Regular Meeting of the Advisory Body Committee Commission CALL TO ORDER A Regular Meeting of the Parks and Recreation Commission was called to order on the 3rd day of August, 2016 at 5:32 p.m. in the City Council Chambers located at 990 Palm Street, San Luis Obispo, California, by Chair Whitener. ROLL CALL Present: Committee Members Douglas Single, Greg Avakian and newly sworn-in Commissioner Rodney Thurman, and Chair Jeff Whitener Absent: Susan Olson, Keri Schwab, Susan Updegrove, Staff: Parks and Recreation Director Shelly Stanwyck, Recreation Supervisor Devin Hyfield, Natural Resources Manager Bob Hill PRESENTATIONS, INTRODUCTIONS, APPOINTMENTS 1. Oath of Office The City Clerk provided the Oath of Office for new Parks and Recreation Commissioner; Rodney Thurman PUBLIC COMMENT ON ITEMS NOT ON THE AGENDA None. CONSENT AGENDA AND CONSIDERATION OF MINUTES ACTION: APPROVE THE MEETING MINUTES OF JULY 6, 2016 AS AMENDED BY COMMITTEE MEMBER AVAKIAN, SECOND BY COMMITTEE MEMBER SINGLE. 2. Consideration of Minutes CARRIED 4:0:0:3 to approve the minutes of the Parks and Recreation Advisory Body for the meeting of 07/06/2016. AYES: AVAKIAN, SINGLE, THURMAN, WHITENER NOES: ABSTAIN: ABSENT: OLSON, SCHWAB, UPDEGROVE 8.b Packet Pg. 101 Attachment: b - Parks and Recreation Commission Draft Minutes of 8-3-16 (1447 : Laguna Lake Dredging and Sediment Project - Preferred DRAFT Minutes – Parks and Recreation Commission Meeting of August 3, 2016 Page 2 PUBLIC HEARINGS AND BUSINESS ITEMS 3. Presentation of Conceptual Designs and Proposed Park Site Plan for Froom/Il Villagio Project ACTION: RECEIVE INFORMATION AND PROVIDE FEEDBACK Contract Planner, Shawna Scott, presented to the Commission the Conceptual Park Site Plan component of the Froom / Il Villagio Specific Plan (Madonna on Los Osos Valley Road Specific Plan). The proposed project would require several entitlements, which would ultimately lead to the development of the project site. The applicant is proposing a mix of land uses including a Continuing Care Retirement Community, housing, commercial, open space, and park land. The applicant has identified an additional, adjacent, 7.4-acre parcel located within the City limits as the potential site for a park. Ms. Scott added that this is the first review of the project by the Parks and Recreation Commission. She noted that the applicant is seeking early feedback from the Commission on the proposed, conceptual, park facilities identified for the Specific Plan, and for the Commission to provide preliminary input with respect to their potential consistency with policies and programs contained in the Parks and Recreation Element before preparing the Draft Specific Plan for the project. Ms. Scott noted that the applicant team met with Parks and Recreation while developing conceptual plans to determine the character and range of improvements desired in a park for this project. The applicant has made an effort to make the character of the proposed park more “naturalistic”, celebrating the “uniqueness of the site”. In addition, parking and access to the open space have been identified as priorities at this location. Ms. Scott said that the applicant is proposing a 4.7-acre park with the following amenities:  Parking lot area to provide approximately 26 spaces  Historic plaza including relocated historic residence and bunkhouse (to be used as a ranger’s office and storage building) and a public restroom  Playground area with naturalistic equipment  Dog park area  Wetland overlook  Trail rest area  Drought-tolerant landscaping Developer Representative, Pam Ricci, RRM spoke about the park design Commission Comments followed. Commissioner Single asked for clarification on screening between current development (Home Depot) and Primary Park in reference to area in between park and home depot. Director Stanwyck responded that loading area could not be adjusted but that fencing could be required to alleviate safety concerns behind the trees. Commissioner Single expressed concern about 8.b Packet Pg. 102 Attachment: b - Parks and Recreation Commission Draft Minutes of 8-3-16 (1447 : Laguna Lake Dredging and Sediment Project - Preferred DRAFT Minutes – Parks and Recreation Commission Meeting of August 3, 2016 Page 3 safety and suggested small fencing. Ms. Ricci responded that the plans at this time are conceptual. Commissioner Thurman asked about workout equipment and the continued usage of the equipment. Commissioner Avakian asked about access to the park with the adjacent Home Depot and Costco traffic. Ms. Ricci commented added that there has been discussion with current stores for alternate routes. Commissioner Avakian commented on senior living and access to the trail through the new proposed neighborhood. Ms. Ricci added that there would be additional pedestrian access between residential trails with a five-minute walk. Commissioner Thurman commented about trailhead plaza being private. Commissioner Avakian asked about lighting and ADA access. Chair Whitener asked about connectivity of the park to City. Ms. Scott responded that the park would connect to Irish hills and current development with potential additional connection. Commissioner Single said he viewed the conceptual park design more as a pocket park and noted the need for a dog park in this area. Chair Whitener added he was not in support of the location as there was not enough usable park space. Public Comments: Michael Parolini, San Luis resident, commented that the conceptual design does not feel like a typical park given its isolation and potential maintenance issues and suggested this located be considered as open space. Neil Havlik, San Luis resident, agreed that this is not an ideal location for a park. John Madonna, San Luis resident, spoke about the ease of access to the trailhead as opposed to the access from Madonna Road. 4. Update for Laguna Lake Dredging Project Relative to Laguna Lake Park ACTION: RECEIVE INFORMATION AND PROVIDE FEEDBACK Natural Resources Manager, Bob Hill, presented the Commission an update on the Laguna Lake Dredging and Sediment Management Project relative to the Laguna Lake Park Area. He added that he is seeking the Commission’s input and consensus relative to the aspects of the project that are pertinent to the recreational uses at Laguna Lake Park and Natural Reserve. Commission Comments followed. Commissioner Thurman commented about capturing sediment attachment into the lake. Hill explained the procedure in excavation of sediment and dewatering plans for removal. 8.b Packet Pg. 103 Attachment: b - Parks and Recreation Commission Draft Minutes of 8-3-16 (1447 : Laguna Lake Dredging and Sediment Project - Preferred DRAFT Minutes – Parks and Recreation Commission Meeting of August 3, 2016 Page 4 Commissioner Single asked about the dry lake conditions and cost associated with dredging. Staff Hill explained difference between hydraulic (wet) and mechanical (dry) dredging and condition of lake during dry conditions. Commissioner Avakian asked about the project duration and impact on other park usage. Staff Hill responded that dredging would potential occur over several seasons to minimize construction impacts and employ a sediment management strategy would limit amount of sediment flowing into lake, thereby minimizing future impacts to the lake. Staff Hill added that there would be minimal impacts to the public and estimated approximately 400 cubic yards per day could be removed (approximately 10 truckloads). Public Comments: Mike Parolini asked about the cost of the project and the tax incurred by the residences of Laguna Lake. John Smeglski, San Luis resident, asked if the improvements to Vista Lago Park would be associated with the project. Staff Hill responded to provide feedback about how the improvements could be incorporated. 5. Selection of Wes Conner Awardee for 2016 Director Stanwyck recommended the Commission postpone this agenda item to the September meeting to allow the full Commission the opportunity to consider and select the Wes Conner awardee. ACTION: MOTION BY COMMITTEE MEMBER AVAKIAN, SECOND BY COMMITTEE MEMBER SINGLE, to recommend postponing the selection of the 2016 Wes Conner Awardee to the September 7, 2016 meeting. Motion passed 4:0:3:0 on the following roll call vote: AYES: AVAKIAN, SINGLE, THURMAN, WHITENER NOES: ABSTAIN: ABSENT: OLSON, SCHWAB, UPDEGROVE 6. Discussion of Annual Park Tour Dates and Topics Director Stanwyck explained the itinerary of annual park tour and potential locations to visit. The Commission agreed to finalize this at its September meeting. COMMITTEE COMMUNICATIONS Director’s Report Director Stanwyck provided a brief overview of current Parks and Recreation programming.  Hydro Flask Rewards for staff  Box Art Policy – Vote for next locations to be painted by August 28th  SLO Triathlon - a Success!  Movies in the Mission, 8/6, 8/13, 8/20 8.b Packet Pg. 104 Attachment: b - Parks and Recreation Commission Draft Minutes of 8-3-16 (1447 : Laguna Lake Dredging and Sediment Project - Preferred DRAFT Minutes – Parks and Recreation Commission Meeting of August 3, 2016 Page 5  Family Overnight Camp Out in Laguna Lake Park will be held on August 13-14  Skate Park Ramp n’ Roll 8/20 (Fun & Educational Event)  Volunteer Appreciation Dinner 9/22 (at Jack House) Commission Communications LIAISON REPORTS  Adult and Senior Programming: Commissioner Single said adult softball ended last week and it was a great season. Fall softball sign-ups are starting. French Park pickleball is being played twice weekly after restriping of the basketball courts. The Ludwick Community Center hosts volleyball and table tennis – and attendance is in good numbers. Adult soccer is starting at Damon Garcia Sports Fields. Seniors are staying active with fun, well-attended, activities at senior center including bunko and bridge. Commissioner Single requested a list of Senior Center Board Meeting dates.  Bicycle Advisory: No report. Commissioner Olson absent.  City Facilities (Damon Garcia, Golf, Pool & Joint Use Facilities): Commissioner Avakian said that summer is busy. Damon-Garcia is open as of August 1 but still closed on Mondays for field recovery. Jack House weddings are booked through October. New tables were ordered for the Ludwick Center. The City/County Library conference room will for library use from October 2016 through January 2017. The Swim Center saw rise in attendance and will be closed for two weeks in August for maintenance. Golf Course had good summer with rounds up 100 from previous month and 550 rounds in one weekend. Increased youth participation at the Golf Course and increase in merchandise sale. Tournaments were held over summer months. Middle school classes held at Golf Course during school year.  Jack House Committee: No Report. Vice Chair Updegrove absent.  Tree Committee: No Report. New subcommittee assignment for Commissioner Thurman.  Youth Sports: Chair Whitener said YSA had some issues with field use due to construction at SLO High School. YSA is planning a meeting with the School District to discuss topics related to youth sports. ADJOURNMENT The meeting was adjourned at 7:55 p.m. The next Regular meeting of the Parks and Recreation Commission is scheduled for 07, September, 2016 at 5:30 p.m., in the City Council Chambers, 990 Palm Street, San Luis Obispo, California. APPROVED BY THE PARKS AND RECREATION COMMISSION: 09/07/2016 8.b Packet Pg. 105 Attachment: b - Parks and Recreation Commission Draft Minutes of 8-3-16 (1447 : Laguna Lake Dredging and Sediment Project - Preferred Page intentionally left blank. Laguna Lake Dredging & Sediment Management Presentation to City Council, September 20, 2016 Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 1 Laguna Lake Dredging & Sediment Management Presentation to City Council, September 20, 2016 Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 2 Receive and file the Preliminary Dredging Report (the “PDR”) prepared by MNS Engineers, Inc. and, as further described in the PDR, direct staff to proceed with further analysis and further recommendations related to the following preferred project alternative: 1.Use of hydraulic or cyclonic dredging equipment as the dredging technology; 2.Removal of 50,000 cubic yards of sediment from the Laguna Lake as the dredging project option; 3.Mechanical dewatering at Laguna Lake Park as the dewatering location and method; 4.Off-site disposal at Cold Canyon Landfill as the sediment deposition location and facility; 5.Creek bank restoration and installation of a sediment basin at Laguna Lake Golf Course along Prefumo Creek, as well as shoreline restoration at the lake itself, as short-term sediment management strategies. Staff Recommendation: Laguna Lake Dredging & Sediment Management Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 3 Laguna Lake Natural Reserve is 344 acres Presentation to City Council, September 20, 2016 Ca. 1900s –Laguna Lake is a naturally occurring freshwater lake Laguna Lake Dredging & Sediment Management Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 4 Presentation to City Council, September 20, 2016 USGS, 1895 –Prefumo Creek did not drain into the lake until ~1960 Laguna Lake Dredging & Sediment Management Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 5 Presentation to City Council, September 20, 2016 1965 1977 Laguna Lake Dredging & Sediment Management 6 Presentation to City Council, September 20, 2016 Laguna Lake Dredging & Sediment Management Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 7 The center of the lake is filling in at a rate of 1”-3” per year on average Presentation to City Council, September 20, 2016 Laguna Lake Dredging & Sediment Management Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 8 Prior Planning & Studies 1.Laguna Lake Master Plan, 1961 2.Laguna Lake Management Plan, 1982 3.Laguna Lake Park Master Plan, 1991 (amended 1998 and 2005) 4.Council Agenda Report, 2009 5.Laguna Lake Natural Reserve Conservation Plan, 2014 Current Work Completed 1.A review the current status of the lake, previous studies, and management documents 2.New geotechnical and water quality testing data 3.New biological and cultural resource assessments 4.A review of applicable dredging technologies and approaches 5.Development of dredging alternatives 6.Recommendations for deposition and disposal of sediments 7.Dredging operations recommendations 8.Recommendations for future sediment management 9.An analysis of project funding options Presentation to City Council, September 20, 2016 Primary Areas of Interest for Dredging Project Laguna Lake Dredging & Sediment Management Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 9 Presentation to City Council, September 20, 2016 Alternative 1 –Small Project –36,500 cubic yards Laguna Lake Dredging & Sediment Management Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 10 Presentation to City Council, September 20, 2016 Alternative 2A –Medium Project –50,000 cubic yards Laguna Lake Dredging & Sediment Management Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 11 Presentation to City Council, September 20, 2016 Alternative 2B –Medium Project –85,000 cubic yards Laguna Lake Dredging & Sediment Management Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 12 Presentation to City Council, September 20, 2016 Alternative 3 –Large Project –167,000 cubic yards Laguna Lake Dredging & Sediment Management Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 13 Presentation to City Council, September 20, 2016 Example Project –City of Westlake Village, CA Laguna Lake Dredging & Sediment Management Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 14 Presentation to City Council, September 20, 2016 Example Project –City of Westlake Village, CA Laguna Lake Dredging & Sediment Management Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 15 Presentation to City Council, September 20, 2016 Example Project –City of Westlake Village, CA Laguna Lake Dredging & Sediment Management Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 16 Presentation to City Council, September 20, 2016 Example Project –City of Westlake Village, CA Laguna Lake Dredging & Sediment Management Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 17 Presentation to City Council, September 20, 2016 Example Project –City of Westlake Village, CA Laguna Lake Dredging & Sediment Management Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 18 Presentation to City Council, September 20, 2016 Potential dewatering and hauling plan Laguna Lake Dredging & Sediment Management Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 19 Presentation to City Council, September 20, 2016 Dredging Project Cost Matrix Laguna Lake Dredging & Sediment Management Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 20 For planning, tipping fee assumed @ $33.75 per CY. Cost estimates include 20% markup for Contractor OH&P and 20% Estimate Contingency. Costs for Mechanical Dredging alternatives may change due to mobilization estimates. Alternative Volume Dredging Method Dewatering Method Total Cost (Million)Cost Per CY 1A 36,500 Hydraulic Dewatering Pond $5.26 $144.11 1B 36,500 Hydraulic Mechanical Dewatering $6.34 $173.77 MECH1 36,500 Mechanical N/A $6.44 $176.31 2A-Low 50,000 Hydraulic Dewatering Pond $6.95 $138.92 2B-Low 50,000 Hydraulic Mechanical Dewatering $8.68 $173.68 MECH2-Low 50,000 Mechanical N/A $7.82 $156.32 2A-High 85,000 Hydraulic Dewatering Pond $11.32 $133.17 2B-High 85,000 Hydraulic Mechanical Dewatering $14.55 $171.22 MECH2-High 85,000 Mechanical N/A $12.75 $150.05 3A 167,000 Hydraulic Dewatering Pond $21.56 $129.12 3B 167,000 Hydraulic Mechanical Dewatering $27.31 $163.50 MECH3 167,000 Mechanical N/A $23.62 $141.45 Presentation to City Council, September 20, 2016 SMALLMEDIUMLOWMEDIUMHIGHLARGE Dredging Project Cost Matrix Laguna Lake Dredging & Sediment Management Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 21 For planning, tipping fee assumed @ $33.75 per CY. Cost estimates include 20% markup for Contractor OH&P and 20% Estimate Contingency. Costs for Mechanical Dredging alternatives may change due to mobilization estimates. Alternative Volume Dredging Method Dewatering Method Total Cost (Million)Cost Per CY 1A 36,500 Hydraulic Dewatering Pond $5.26 $144.11 1B 36,500 Hydraulic Mechanical Dewatering $6.34 $173.77 MECH1 36,500 Mechanical N/A $6.44 $176.31 2A-Low 50,000 Hydraulic Dewatering Pond $6.95 $138.92 2B-Low 50,000 Hydraulic Mechanical Dewatering $8.68 $173.68 MECH2-Low 50,000 Mechanical N/A $7.82 $156.32 2A-High 85,000 Hydraulic Dewatering Pond $11.32 $133.17 2B-High 85,000 Hydraulic Mechanical Dewatering $14.55 $171.22 MECH2-High 85,000 Mechanical N/A $12.75 $150.05 3A 167,000 Hydraulic Dewatering Pond $21.56 $129.12 3B 167,000 Hydraulic Mechanical Dewatering $27.31 $163.50 MECH3 167,000 Mechanical N/A $23.62 $141.45 Presentation to City Council, September 20, 2016 SMALLMEDIUMLOWMEDIUMHIGHLARGE Examples of erosion sources in the watershed above the lake Photo credit: Aleksandra Wydzga Laguna Lake Dredging & Sediment Management Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 22 Presentation to City Council, September 20, 2016 Areas to address erosion sources above the lake Photo credit: Aleksandra Wydzga Laguna Lake Dredging & Sediment Management Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 23 Presentation to City Council, September 20, 2016 Examples of erosion sources within the Laguna Lake Natural Reserve Photo credit: Aleksandra Wydzga Photo credit: Aleksandra Wydzga Laguna Lake Dredging & Sediment Management 24 Presentation to City Council, September 20, 2016 Laguna Lake Watershed Map Laguna Lake Dredging & Sediment Management Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 25 Presentation to City Council, September 20, 2016 Laguna Lake Dredging & Sediment Management Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 26 Accessible Path, Signs & Kiosks, Peninsula Boardwalk, Viewing Platforms, and Boat Launch Area Presentation to City Council, September 20, 2016 Laguna Lake Dredging & Sediment Management Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 27 Potential Funding Options and Strategy 1.State of California Grant Funding: a)Peninsula Boardwalk -CA Department of Parks and Recreation, Habitat Conservation Fund Trails Program b)Boat Launch and Parking Area –CA Department of Boating and Waterways c)Creek and Shoreline Stabilization Projects, Fish Passage Improvements –CA Wildlife Conservation Board 2. Land-Based Financing: a)Benefit Assessment District, or b)Community Facilities District 3.City of San Luis Obispo General Fund 4.Infrastructure State Revolving Fund (ISRF) Loan, California Infrastructure and Economic Development Bank Presentation to City Council, September 20, 2016 Laguna Lake Dredging & Sediment Management Brief Project History Dredging Options Sediment Management Options Project Amenities Financing Options Next Steps 28 Next Steps 1.MNS prepares 95% Plans, Specifications & Engineering for preferred project alternative 2.Staff and consultant team continues to evaluate and refine financing options through public opinion research and outreach, as well as legal and technical review 3.Staff and consultant team pursues regulatory permits and prepares CEQA documents for preferred project alternative 4.Staff and consultant team return to City Council with next steps related to financing options. Presentation to City Council, September 20, 2016 Robert A. Hill Natural Resources Manager (805) 781-7211 or rhill@slocity.org Derek Johnson Assistant City Manager (805) 781-7112 or djohnson@slocity.org Doug Pike Principal Engineer MNS Engineers (805) 688-5200 or dpike@mnsengineers.com Photo credit: Halden Petersen Staff Recommendation: Laguna Lake Dredging & Sediment Management 29 Presentation to City Council, September 20, 2016 Receive and file the Preliminary Dredging Report (the “PDR”) prepared by MNS Engineers, Inc. and, as further described in the PDR, direct staff to proceed with further analysis and further recommendations related to the following preferred project alternative: 1.Use of hydraulic or cyclonic dredging equipment as the dredging technology; 2.Removal of 50,000 cubic yards of sediment from the Laguna Lake as the dredging project option; 3.Mechanical dewatering at Laguna Lake Park as the dewatering location and method; 4.Off-site disposal at Cold Canyon Landfill as the sediment deposition location and facility; 5.Creek bank restoration and installation of a sediment basin at Laguna Lake Golf Course along Prefumo Creek, as well as shoreline restoration at the lake itself, as short-term sediment management strategies.