May 19, 2001 Memo from Stan Isley to the 2001 Drought Water Transfers Group Describing a Proposed Methodology for Determining the Quantity of Water Transferable to KRD or RID in the Yakima River Basin, while Maintaining Water Budget Neutrality to TWSA

Memorandum

To: 2001 Drought Water Transfers Group

From: Stan Isley

Date: May 19, 2001

Subject: Proposed Methodology for Calculating TWSA Water Budget Neutral Water Transfer Quantities Using Consumptive Use Calculations

At the May 14, 2001 meeting of our 2001 drought water transfers group, all participants agreed that I should draft a proposed methodology for calculating the amount of water that can be transferred in 2001 from leased tributary water rights to the Roza Irrigation District (RID) and the Kittitas Reclamation District (KRD). The consensus was that I should base the methodology on an analysis of crop consumptive use (crop irrigation water requirements - CIR) as defined by the Washington Irrigation Guide (WIG), but modified to reflect the serious drought conditions we=re experiencing in the Yakima River valley in 2001. It is our intent to develop a methodology that will have widespread applicability for the remaining transfer proposals we receive this year. I have worked at length with Bob Barwin (on 5/14), Stephen Fanciullo (5/16), and Jim Esget (5/17) to develop the following guidance and methodology. I think it makes sense and ensures no impairment of other rights will result from transfers approved under these guidelines.

Assumptions

1) Water transfers must be water budget neutral to the TWSA.

2) The TWSA is calculated at Parker.

3) All KRD return flows return to the Yakima River above Parker (within 3 months).

4) Only six percent (6%) of the water diverted by RID into its canal at Roza Dam returns to the Yakima River above Parker (also within three months) [USBR study, circa early 1990's].

5) All irrigated lands, representing the fallowed place of use of the leased water rights, are to be fallowed for the full 2001 irrigation season, to allow transfer of the maximum amount of the right to the lessee (RID & KRD).

6) Only May 1 to September 30 water right quantities can be bucketed and transferred (without impact to TWSA).

7) Transfers to KRD require an analysis to ensure that no net increase in consumptive use occurs (matching the consumptive uses). Reclamation canal efficiency and return flow studies exist and are helpful in matching the consumptive uses from lessor to lessee.

8) Transfers to RID require a slightly modified analysis since most of RID return flows return to the Yakima River below Parker and, therefore, are lost to TWSA. RID transfer quantities are limited to fallowed CIR=s plus the credit for the 6% return flow quantity which is lost from the upper part of the RID canal system and returns to the Yakima River above Parker.

9) Transfers of water rights can not exceed the maximum water right amount of the leased water right, no matter what theoretical consumptive use quantity the methodology estimates.

10) The WIG CIR=s are based on average year (1 in 2 year returns/climatological conditions). The WIG CIR=s must be adjusted upward to reflect the drought year CIR=s (1 in 10 year returns/climatological conditions).

Adjusting the WIG CIR=s

Reviewing the formulas used by WSU and NRCS in deriving the CIR figures in the WIG reveals that simple assumptions can be made to quickly adapt the WIG=s CIR quantities (1 in 2 year returns) to reflect the greater crop irrigation water demand under 1 in 10 year drought conditions, like we are experiencing this year, in 2001. Lower soil water content, hotter temperatures, windy desiccating conditions, lower snow pack, lower precipitation amounts during growing season, all of these factors can be expected when the Yakima valley is experiencing drought conditions. In our valley, poor carryover reservoir storage levels are also a factor in worsening the effects of the drought (largely a separate consideration though - not affecting the CIR, rather affecting total water supply available). Bob Barwin=s recent analysis of drought year CIR calculations, based on the 1 in 10 year returns, indicates that we can use the following simple adjustments to the CIR quantities in the WIG:

1) Cle Elum climate station - WIG plus 3 inches (for 1 in 10 year climate adjustment) plus 2 inches (for less effective precipitation during the growing season) = WIG + 5 inches.

2) Ellensburg - WIG plus 3 inches (1 in 10 year adjustment) plus 1 inch (growing season effective precipitation adjustment) = WIG + 4 inches.

3) Yakima - WIG plus 3 inches (1 in 10 year adjustment) plus 1 inch (growing season effective precipitation adjustment) = WIG + 4 inches.

These simple formulas allow us to quickly adjust the WIG CIR=s to reflect the higher CIR=s under 2001 drought conditions.

Example Adjustment

Using the WIG, I can look up the CIR for clover at Yakima, which is given as just over 39 inches (39.25). Then, using the simplified formula above, I conclude that the year-2001 CIR for clover at Yakima is WIG + 4 = 39 + 4 = 43 inches. This represents an approximate increase of AWIG times 1.102" (i.e., just over 110% of the WIG average-year CIR estimate).

Since only May 1 through September 30 water can be bucketed and transferred without negative impact to TWSA, and the Yakima WIG CIR estimates show a small CIR in April and also in October, April and October CIR=s must be subtracted from the seasonal CIR calculation. The WIG=s monthly CIR figures from May through September must be individually adjusted to derive 2001 drought-year CIR=s for each month (AWIG monthly CIR times 1.102"). Then these adjusted monthly CIR=s must be totaled to give the adjusted May through September 2001 CIR totals that can be transferred.

Transfers to RID

Once the adjusted May through September CIR is calculated, as above, for the right to be fallowed and transferred, the following must be done if the quantity is to be transferred to RID:

Since 6% of the amount of water diverted by RID returns to the Yakima River and to the TWSA above Parker, the May - Sept CIR quantity represents 94% of what can be diverted by RID into its canal system at Roza Dam while still ensuring that only the May - Sept CIR quantity is consumed to the TWSA. Therefore, one must divide the May - Sept CIR figure by 0.94. This resulting quantity is the maximum amount of water that RID can divert without negatively affecting the TWSA.

One additional note: One must compare the calculated May - Sept CIR quantity to the maximum limit of the water right to ensure that the theoretical drought-year CIR does not exceed the water right limits. No more than the maximum limits of the water right can be transferred for diversion by RID (or by KRD, et al.).

Applying the Proposed Methodology

WTP #2001-10 Cromarty to RID transfer proposal:

The Cromartys= two 1902-priority Teanaway River water rights total 2.02 cfs, 404 acre-feet per year for irrigation of 101 acres and stock water from May 1 through September 15 each year. These rights are junior compared to the other rights in the Teanaway River subbasin. Therefore, the Cromartys are likely to only have water available to satisfy these rights until July 15, 2001. Adjusting the WIG CIR=s (for clover at Cle Elum) to AWIG + 5 inches@ for the months of May, June and July 1 - 15, provides the adjusted 2001-year CIR quantity of 8.79 inches = 0.7325 feet x 101 acres = 74.0 acre-feet transferable to RID. Then, dividing 74.0 by 0.94 (RID return flow adjustment) gives a figure of 78.7 acre-feet that RID can divert and use while still remaining water budget neutral to the TWSA. The Cromartys= rights will be fallowed all irrigation season in the Teanaway subbasin.

WTP #2001-11 Rupel to RID transfer proposal:

The Rupels= two 1867-priority Wenas Creek water rights total 0.314 cfs, 47.1 acre-feet per year for irrigation of 15.7 acres from April 1 to October 15 each year. These senior water rights are expected to enjoy full season availability in the 2001 irrigation season. Adjusting the WIG CIR=s (for pasture at Yakima) to AWIG + 4 inches@ for the months of May through September provides the adjusted 2001-year CIR quantity of 38.63 inches = 3.22 feet x 15.7 acres = 50.5 acre-feet theoretically transferable to RID. However, this figure is slightly higher than the maximum limit of the water right. Therefore, only the maximum limit of the water right, 47.1 acre-feet can be bucketed and transferred to RID. No return flow adjustment can be made for the RID canal loss of 6% (return flows) above Parker either. RID must simply accept all canal conveyance losses out of the 47.1 acre-feet of transferred water. The Rupels= rights will be fallowed all irrigation season in the Wenas subbasin.

WTP #2001-12 Masterson to RID transfer proposal:

Mr. Masterson=s 1883-priority Teanaway River water right totals 4.8 cfs, 1527.5 acre-feet per year for irrigation of 235 acres and stock water from May 1 through September 15 each year. This senior right is expected to enjoy full season availability in the 2001 irrigation season. Adjusting the WIG CIR=s (for clover at Cle Elum) to AWIG + 5 inches@ for the whole season of use provides the adjusted 2001-year CIR quantity of 24 inches = 2.0 feet x 235 acres = 470 acre-feet transferable to RID. Then, dividing by 0.94 gives a figure of 500 acre-feet that RID can divert and use while remaining water budget neutral to the TWSA. Mr. Masterson=s right will be fallowed for the entire irrigation season in the Teanaway subbasin.

WTP #2001-15 Coe to RID transfer proposal:

Bruce Coe=s two 1884-priority Swauk Creek water rights total 3.29 cfs, 276.5 acre-feet per year for irrigation of 50 acres from April 1 through October 15 each year. These two rights are relatively junior rights from Swauk Creek. Therefore, Mr. Coe would likely only have water available to satisfy these two rights until July 15, 2001. Adjusting the CIR=s (for clover at Swauk Creek as recently analyzed by Tom Martin, consultant for Trendwest) to A28.61 inches plus 4 inches@ provides an adjusted 2001-year full-season CIR quantity that is 99% of the normal year WIG CIR for clover at Ellensburg. Applying this 99% ratio to the May through July 15, 2001 period Ellensburg WIG CIR=s for clover provides the adjusted 2001-year CIR quantity of 15.16 inches = 1.26 feet x 50 acres = 63.2 acre-feet transferable to RID (= fallowed CIR). Then, dividing by 0.94 gives a figure of 67.2 acre-feet which RID can divert and use while remaining water budget neutral to the TWSA. Mr. Coe=s rights will be fallowed for the entire irrigation season in the Teanaway subbasin.

WTP #2001-16 SNID to RID transfer proposal:

SNID fallowed acreage totals 216.65 acres (118 acres on the Powell Ditch, 42.96 acres on the LaFortune Ditch, and 55.69 acres on the Scott Ditch). These SNID water rights are: 3.54 cfs, 1234.3 acre-feet for the Powell Ditch 118 acres; 1.29 cfs, 307.6 acre-feet for the LaFortune Ditch 42.96 acres; 1.67 cfs, 675.5 acre-feet for the Scott Ditch 55.69 acres; for a total of 6.5 cfs, 2217.4 acre-feet for irrigation from April 1 to October 31 each year. These 1886 and 1892-priority water rights can expect to enjoy full season availability in 2001. Adjusting the WIG CIR=s (for clover at Yakima) to AWIG + 4 inches@ for the May through September period provides the adjusted 2001-year CIR quantity of 40.47 inches = 3.37 feet x 216.65 acres = 730.65 acre-feet (= fallowed CIR) transferable to RID. Then, dividing by 0.94 gives a figure of 777.3 acre-feet that RID can divert and use while remaining water budget neutral to the TWSA. SNID=s non-proratable TWSA bucket will be debited (6.5 cfs,) 2217.4 acre-feet for 2001. The SNID 216.65 acres will be fallowed all irrigation season.

WTP #2001-17 NSID to RID transfer proposal:

NSID fallowed acreage totals 127.2 acres. NSID has natural flow rights (1880 to 1890 priorities) to 46,254 acre-feet for irrigation of 10,600 acres from April 1 through October 31 each year (35,044 acre-feet from May through September), and 4486 acre-feet of storage rights (1905-priority proratable rights). April=s 674 acre-feet of storage rights are assumed to no longer be available to NSID, leaving a total of 3812 acre-feet of storage water available to NSID. With a 29% storage water prorationing forecast (May 1^st forecast), 3812 x 0.29 leaves 1105.5 acre-feet of storage water available to NSID for the May through September 2001 period. A total of 36,149 (35,044 + 1105) acre-feet of NSID water is expected to be available from May through September 2001, divided by 10,600 acres = 3.41 acre-feet per acre water duty for NSID for the May through September 2001 period x 127.2 acres = 433.8 acre-feet of maximum water right for these 127.2 fallowed acres. The diversion rates authorized for these 127.2 acres are 1.45 cfs in May, 1.46 cfs in June, 1.52 cfs in both July and August, and 1.36 cfs in September. The NSID TWSA water bucket will be debited (between 1.36 and 1.52 cfs, per the monthly schedule,) 433.8 acre-feet for 2001. The NSID 127.2 acres will be fallowed all irrigation season.

Adjusting the WIG CIR=s (for apples with cover at Yakima) to AWIG + 4 inches@ for the May through September period provides the adjusted 2001-year CIR quantity of 44.27 inches = 3.69 feet x 127.2 acres = 469.3 acre-feet (fallowed CIR) transferable to RID. Then, dividing by 0.94 gives a figure of 499.3 acre-feet which RID could theoretically divert and use while remaining water budget neutral to the TWSA.

However, this method calculates a 2001 drought-year CIR that=s slightly higher than the maximum limit of the water right. Therefore, only the maximum limit of the water right, 433.8 acre-feet can be bucketed and transferred to RID. No return flow adjustment can be made for the RID canal loss of 6% (return flows) above Parker either. RID must simply accept all canal conveyance losses out of the 433.8 acre-feet of transferred water.

Conclusion

The above calculations provide a best approximation of the transferable quantities of the several water rights that can be transferred while still maintaining water budget neutrality to TWSA.