B08__A6_Drawing_Comparison_Report.pdf

This document is a Forebay Record Drawing Comparison Report for the BIA-WIP Drop 1 Pumping Plant, prepared by Anderson Perry & Associates in January 2023 for Jacobs. The report details a topographic survey conducted between October and November 2022 of the Bureau of Indian Affairs Wapato Irrigation Project (WIP) Drop 1 Pumping Plant, located in the Yakama Nation, Yakama County, Washington.

The survey involved comparing three existing design documents: a location map, a pumping plant sections drawing, and a water surface sensitive flap gate drawing. Key findings include detailed measurements of the forebay structure, including bay widths (averaging 9.5 feet), dividing wall widths (around 2.0 feet), and various elevation measurements referenced to the North American Vertical Datum of 1988 (NAVD88). The survey was conducted using a Trimble GPS system with precise control points and aimed to document discrepancies between current on-site conditions and historical design drawings, providing a comprehensive record of the existing pumping plant infrastructure.