RES 164 Draft 01 2022-2024 - Laserfiche WebLink

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1. GENERAL This preliminary engineering report is in support of the proposed Iki Place Water System Improvements (Project) within the Iki Place subdivision. The Project is intended to be funded through the United States Department of Agriculture (USDA), Rural Development(RD), Rural Utilities Water and Waste Disposal Loan and Grant Program. This program funds municipal projects such as this with a combination of loan and grant monies. The loan portion of the funding is repaid to the USDA over a specified period by the applicant - in this case the Hawaii County Department of Water Supply (DWS) -while the grant portion of the funding does not require repayment. The Hawaii County Council has initiated an Improvement District(ID), which will ensure the repayment of the loaned funds. The Project is to consist of a new water system conforming to current DWS standards and is intended to provide adequate fire protection and reliable and safe potable water service to the residents of the subdivision. The existing and proposed water system is served by DWS's North Kona Water System. The sources of supply are groundwater wells and a groundwater shaft. Water is pumped from the sources to DWS's 0.3 MG Kalaoa Tank which then feeds the system via gravity. Beginning at the outlet of the tank, an existing 8-inch main runs down an access road and feeds a 12-inch main in Mamalahoa Highway. This main subsequently supplies an 8-inch main in Akamai Street which flows to the 8-inch main in Aniani Street where the proposed point of connection for the new water system lies. A pressure reducing valve station (PRV) located at approximately elevation 1468 in Akamai Street is set to 55 psi and will provide adequate pressure to the proposed water system without requiring changes to the existing water system or installation of additional PRVs. The proposed water system improvements consist of approximately 1,150 linear feet of new 8- inch water main, individual 5/8-inch meters for each lot, and two (2) fire hydrants located in accordance with current DWS standards. The project will also include modifications to the banks of meters located within the Mamalahoa Highway ROW. Work following installation of the water system improvements will include re-paving and striping of the portions of the Aniani Street, Iki Place and Kona Church of God Road ROWs impacted by water system installation as necessary. Traffic control during all phases of construction will also be required. 2. PROJECT PLANNING a. Location The Iki Place Subdivision is a residential subdivision within the ahupuaa of Kohanaiki in the North Kona District on the Island of Hawaii, State of Hawaii. It is more particularly located on the makai (west) side of the Mamalahoa Highway and is on the western slope of Hualalai. The subdivision was created in 1961 and currently consists of 18 residential lots ranging in size from 7,632 to 10,089 square feet. The subdivision is accessed via a single thirty (30) foot wide right- of-way (ROW) designated Iki Place, which generally runs north-south and is privately owned by the homeowners association. Elevations within the subdivision range from between 1430 feet to 1450 feet. The average slope is approximately 10%running east to west. There are currently no water mains, or hydrants within the subdivision, however DWS is currently providing domestic water service to fifteen(15) of the eighteen(18) lots via 5/8"water meters located along the Mamalahoa Highway. Small diameter PVC &HDPE pipes run makai (west) down the Kona Church of God Road ROW to service homes on these lots. The distance from the meters along Mamalahoa Highway to the most distant homes served is approximately 1,500 feet. There are 1