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Home My WebLink AboutTIS 2024-04-24 Item 2J - Update - Future Water ReservoirCity of Tukwila Public Works Department - Hari Ponnekanti, Director/City Engineer Thomas McLeod, Mayor INFORMATIONAL MEMORANDUM TO: Transportation Infrastructure Committee FROM: Hari Ponnekanti, Public Works Director/City Engineer BY: Adib Altallal, Utilities Engineer CC: Mayor Tom McLeod DATE: April 19, 2024 SUBJECT: Water Fund — Future Water Reservoir Update Project No. 91240102 Siting Update — Discussion Only ISSUE Provide an update on the progress of searching for a property for a future water reservoir. BACKGROUND During the City of Tukwila's 2015 Water Comprehensive Plan, the consultant identified that the continued growth within the City no longer meets the Department of Health's water storage requirements. As a result, the Water Reservoir and Pump Station was included in the Capital Improvement Program. During the most recent Water Comprehensive Plan update, the City's water storage deficiencies were highlighted again. Further development throughout the City and especially in the Ryan Hill and Tukwila South areas are likely to be hindered or completely halted due to these water storage deficiencies. Old Fire Station 52 has been identified as a possible future site of the reservoir. The construction of a new reservoir at the site would save the City's General Fund money by taking over the responsibilities of the demolition and mitigation of the building. Further, the project would greatly improve the condition of Hazelnut Park by expanding the area and adding recreational items for the residents' use. Staff most recently discussed this option with Council at the April and July,2023 Transportation and Infrastructure Services Committee meetings and the subsequent Committee of the Whole meetings. ANALYSIS The results of the feasibility study conducted by Carollo and HWA indicated favorable results of the soil test. Though soil stability can vary drastically within the same parcel, soil samples indicated great likelihood that we can excavate to the appropriate depth to construct a fully or partially buried water reservoir. Next steps will include narrowing the design to two general alternatives, advertising for design proposals, then bringing this item back to the Transportation and Infrastructure Services Committee to award a design contract. RECOMMENDATION This item is for discussion only. Attachments: 2024 CIP, Page 56 Water System Slides 153 CITY OF TUKWILA CAPITAL PROJECT SUMMARY 2023 to 2028 PROJECT: Water Reservoir and Pump Station Project No. 91240102 DESCRIPTION: Design and construct a new 2.5 MG water reservoir with a pump station. JUSTIFICATION: The Department of Health is requiring the City provide additional water storage. A pump station is needed for fire flow. STATUS: Design funds will be used to update and expand the siting study Carollo completed in 2014 and updated in 2021. MAINT. IMPACT: Additional staff will be needed to provide maintenance for the new reservoir and pumps. COMMENT: FINANCIAL Through Estimated (in $000's) 2021 2022 2023 2024 2025 2026 2027 2028 BEYOND TOTAL EXPENSES Design 7 500 500 1,007 Land (R/W) 750 1,000 1,750 Const. Mgmt. 500 500 1,000 Construction 2,000 3,600 7,000 12,600 TOTAL EXPENSES 7 0 0 750 1,000 3,000 4,600 0 7,000 16,357 FUND SOURCES Awarded Grant 0 Proposed Grant 1,000 1,000 Bond 750 1,000 3,000 3,600 8,350 Mitigation Expected 0 Utility Revenue 7 0 0 0 0 0 0 0 7,000 7,007 TOTAL SOURCES 7 0 0 750 1,000 3,000 4,600 0 7,000 16,357 Location to be determined. 2023 - 2028 Capital Improvement Program 803-14 15`4 it; 4Y 'Pi sw= zHazelnut Park Reservoir Feasibility Study 14475 59th Avenue S Water Supply Distribution System Water Reservoir Treatment Plant • Source' Note: Pumps and valves are located at a variety of locations throughout the distribution system. l\Lirn • Water Source: We purchase treated water from Seattle, drawn from the Tolt and Cedar rivers. • Storage and Distribution: Our existing and planned reservoirs store and distribute water via pumps and gravity. • Interconnected Systems: Seattle's intertie connects our water systems, ensuring supply reliability. • Community Impact: Both commercial and residential properties benefit from our water distribution, covering approximately 70% of the City. • Future Planning: We're expanding infrastructure to meet growing demands and ensure long-term sustainability. • 2.5 MG is equivalent to one person taking two baths a day (-40 gallons each), everyday for 85 years. • ...or 125 Tukwila swimming pools. 301 Site Location Th 141st 42nd Re 13 7th 4tte r Park S 13 4` Showalter I Tukwila Middle Foyer High Fool Schoof r School 144th $ E S 145tt St S 14$th St S15i St 0 Thorndyke 152n0 �5t Elementary a 156th St Crystal nrinerer� rlr L 1f1JSS: •M t - Tukwil. Pkwy ••iOh■ ■ i Mt ■ ■ i 1 Site oaf CAROL 3 Existinc Improvements • Hazelnut Park to remain • Tukwila Heritage and Cultural Center to remain • Vacated fire station to be demolished • Adjacent residential properties Hazelnut Park Heritage Center Fire Station CAROL 4 Currently Underway: Alternatives Analysis • Three alternatives: Concrete reservoir, partially buried Concrete reservoir, fully buried Steel tank reservoir, above grade • Booster pump station required for all alternatives • Six evaluation criteria -> Construction Cost Risk Lifecyle/ Maintenance Community Impacts Land Use Code Community Benefits CAROL 5 Example Reservoir (Partially Buried) • 2.5 MG prestressed, partially buried concrete tank • 112' diameter, 28' height • Alpine, CA • Opportunities to incorporate pickleball or other recreational facilities on top CAROL 6 Example Reservoir (Fully Below Grade) • Crestview Park, Tukwila Highline Water District reservoir (7.6 MG) • Seward Park, Seattle Seattle Public Utilities CSO storage facility (2.65 MG) CAROL 7 Example Reservoir (Steel Tank) • Mercer Island, WA (2) 4 MG reservoirs • Sammamish Plateau 2 MG Next Steps • Complete alternatives analysis and select preferred alternative • Finalize Feasibility Study Report (April 2024) • City determination of whether to proceed with site and alternative Scope design contract for preferred alternative Scope design contract for service level intertie to allow multi -zone storage utilization CAROL 9