Oregon Administrative Rules › Chapter 690 - WATER RESOURCES DEPARTMENT › Division 20 - DAM SAFETY › Section 690-020-0060 - Design Requirements for New Dams or to Increase Dam Height: Construction Specifications

Current through Register Vol. 63, No. 7, July 1, 2024
All drawings for Dams must be accompanied by construction and
				material specifications that include the following:
(1) Construction conditions. Specifications
			 must include the construction period based on typical weather and stream
			 conditions for that location and if applicable, may include a process for the
			 Engineer of Record to modify the construction period;
(2) Clearing of the Dam site and reservoir.
			 Specifications must include the area to be submerged by the new or enlarged
			 reservoir and specify that the submerged area shall be cleared of logs and
			 debris prior to filling the reservoir. The specifications must require that the
			 footprint of the Dam shall be cleared of all soils containing organic
			 materials, and that this material may not be used for Dam
			 construction;
(3) Cutoff Trench
			 requirements. Specifications must include the minimum trench depth, width at
			 base of the trench, and maximum side slope steepness. These specifications
			 shall be based on the subsurface investigations and direct that the Cutoff
			 Trench may not be filled if it contains standing Water. Specifications must
			 also include a requirement not to begin filling the Cutoff Trench until
			 approved by Engineer of Record, and where specified, approved by the
			 Department;
(4) Material
			 specification standards. The specifications shall include material and testing
			 specifications for Dam materials, Conduits, control structures, and other
			 appurtenant structures, using an ASTM standard methodology if
			 available;
(5) Soil Compaction. The
			 typical compaction specification is 95 percent of standard proctor density,
			 though the Engineer of Record may use a different compaction standard.
			 Specifications shall include the types of acceptable compaction equipment, by
			 material source if necessary. Specifications shall also include maximum lift
			 thickness. Specifications shall prohibit soil compaction dry of optimum
			 moisture content to reduce potential for leakage around the Conduit. For
			 materials placed immediately above or adjacent to the Conduit, specifications
			 must also include verification testing of soils, with representative samples
			 selected for testing as directed by the Engineer of Record. Specifications must
			 also require verification of testing of soil compaction, with representative
			 samples selected for testing by the Engineer of Record, or Engineer's
			 representative;
(6) Concrete
			 placement. Specifications shall include means to prevent separation of
			 aggregate and cement, air entrainment requirements if needed, methods for
			 placement and vibration of concrete, required minimum 28 day strength, slump,
			 moisture and temperature requirements for curing. Alkali reactive aggregate
			 shall not be used in the concrete;
(7) Conduit specifications. Specifications
			 must include the material, diameter, and thickness of the Conduit, and the
			 length of Conduit required for the project. Methods for sealing joints must be
			 specific. Specifications must require that all materials from a manufacturer
			 are certified to meet this test, or that the Engineer of Record has tested the
			 materials directly;
(8) Accepting
			 and Rejecting Materials. Specifications must include tolerances for acceptable
			 departure from material specifications and a process for rejection of defective
			 materials or workmanship;
(9)
			 Notification by the Engineer of Record to the State Engineer of changed
			 conditions critical to the safety or operations of the Dam. Specifications
			 shall include State Engineer notification if previously unidentified springs,
			 slope movement or sand lenses are identified, or if storm or other damage
			 occurs during construction;
(10)
			 The Engineer of Record or their qualified employees must supervise construction
			 as needed to assure compliance with the approved construction plans and
			 specifications; and
(11) The
			 specifications must also contain a provision to the effect that plans or
			 specifications shall not be altered or changed without the written approval of
			 the State Engineer.
Statutory/Other Authority: ORS
				  536.027,
				  540.488
Statutes/Other Implemented: ORS 540.449,
				  540.488