OAR 690-507-0800
Stage Gulch CGWA: Method for Determining the Sustainable Annual Yield


(1)

The Department shall determine the sustainable annual yield for each subarea by comparing the volume of groundwater pumped annually from each subarea for a given year to the average of the annual changes in groundwater levels for the area for the same year:

(a)

The Department shall calculate pumpage from each well based on data collected by the Department and as submitted under OAR 690-507-0780 (Stage Gulch CGWA: Duties of Water Users). The pumpage for each subarea shall be calculated by totaling the pumpage from each well in the subarea required to have a flow meter;

(b)

The Department shall calculate annual change in groundwater levels for a subarea by subtracting the current year’s February or March water level from the previous year’s February or March water level. The average shall be calculated by adding the change at each well in the subarea and dividing by the number of wells with available water level data. Data from all permitted or certificated wells in each subarea that are measurable shall be used to calculate the average annual change. If water level data cannot be collected at a particular well, data from a nearby well may be substituted.

(2)

The total volume of groundwater pumped from each subarea for a given year shall be plotted against the average change in groundwater levels from that subarea for that year.

(3)

A line of regression is drawn through the data using the least squares fit method and extended through the zero decline axis.

(4)

The initial determination of sustainable annual yield for subareas B, C, and F of the Stage Gulch Critical Groundwater Area shall be based on the average annual pumpage in each subarea during the period 1985 through 1989, rounded upward to the nearest 50 acre-feet.

Source: Rule 690-507-0800 — Stage Gulch CGWA: Method for Determining the Sustainable Annual Yield, https://secure.­sos.­state.­or.­us/oard/view.­action?ruleNumber=690-507-0800.

690‑507‑0010
Definitions
690‑507‑0020
Policies
690‑507‑0030
Walla Walla River Subbasin
690‑507‑0040
Wildhorse Creek Subbasin
690‑507‑0050
Upper Umatilla River Subbasin
690‑507‑0060
Birch and McKay Creeks Subbasin
690‑507‑0070
Columbia-Umatilla Plateau Subbasin
690‑507‑0080
Butter Creek Subbasin
690‑507‑0090
Willow Creek Subbasin
690‑507‑0610
Butter Creek Critical Groundwater Area (CGWA): Purpose
690‑507‑0620
Butter Creek CGWA: Definitions
690‑507‑0630
Butter Creek CGWA: General Requirements
690‑507‑0635
Butter Creek CGWA: Water Users Exempt from Division Requirements
690‑507‑0640
Butter Creek CGWA: Duties of Water Users
690‑507‑0645
Butter Creek CGWA: Flow Meter Specifications and Installation Guidelines
690‑507‑0647
Butter Creek CGWA: New Subarea Boundaries
690‑507‑0650
Butter Creek CGWA: Sustainable Annual Yield
690‑507‑0660
Butter Creek CGWA: Method for Determining the Sustainable Annual Yield
690‑507‑0670
Butter Creek CGWA: Distribution of Sustainable Annual Yield
690‑507‑0680
Butter Creek (CGWA) Process of Periodic Review of Sustainable Annual Yield
690‑507‑0690
Butter Creek (CGWA) Annual Reporting
690‑507‑0700
Butter Creek CGWA: Violation Policy
690‑507‑0750
Stage Gulch Critical Groundwater Area (CGWA): Purpose
690‑507‑0760
Stage Gulch CGWA: Definitions
690‑507‑0770
Stage Gulch CGWA: General Requirements
690‑507‑0775
Stage Gulch CGWA: Water Users Exempt from Division Requirements
690‑507‑0780
Stage Gulch CGWA: Duties of Water Users
690‑507‑0785
Stage Gulch CGWA: Flow Meter Specifications and Installation Guidelines
690‑507‑0790
Stage Gulch CGWA: Sustainable Annual Yield
690‑507‑0800
Stage Gulch CGWA: Method for Determining the Sustainable Annual Yield
690‑507‑0810
Stage Gulch CGWA: Distribution of Sustainable Annual Yield
690‑507‑0820
Stage Gulch CGWA: Process of Periodic Review of Sustainable Annual Yield
690‑507‑0830
Stage Gulch CGWA: Annual Reporting
690‑507‑0840
Stage Gulch CGWA: Violation Policy
Last Updated

Jun. 8, 2021

Rule 690-507-0800’s source at or​.us