Wyoming State Water Plan, Wyoming Water Development Office
Rafting on Snake River Lake Marie, Snowy Mountains Wyoming Wind River Range picture

Bear River Basin Water Plan
Technical Memoranda

SUBJECT: Appendix D
Key Structures and Diversions
Lannon & Lone Mountain Diversion

PREPARED BY: Bear River Basin Planning Team





	




Diversion Description:  The diversion control structure consists of a single 48-inch CPM 
culvert with a steel slide gate. The river is diverted approximately 200 feet upstream of 
the diversion gate.  The river channel is diverted using a hand placed rock dam.




Lannon & Lone Mountain diversion gate





Diversion Location:	Diversion is on the Upper Bear in Utah.  Irrigated lands are located in 
Wyoming  as shown in the location map hereafter.

			

Latitude  	N   40° 59' 16.1"	

Longitude  	W  110° 51'  46.1"






Conveyance Description: Open Channel Canal, approximately 10,560 feet in length.1







Direct Flow Water Rights:2







Priority Date 
Permit 
Number		
Permitted Use 
Permitted 
Acres		 
Flow 
(CFS)		
Cumulative 
(CFS)		 
Comments



-1898 
U21-26&37
Irrigation & Storage 
864.69
13.42 
13.42 
Lannon (Utah) -
overlaps WY proof
 9127



06-23-1910 
U21-312
Irrigation & Storage 
305.16
4.50 
17.92 
Lone Mountain -
Undefined in WY or
compact







Bear River Compact:  Although the Lannon & Lone Mountain Diversion is located in Utah, the 
Bear River Compact acknowledges Wyoming's right to administer these water rights.   
Article X, Paragraph "B"  of the Compact specifically states: 



"B.  All interstate rights shall be administered by the state in which the point of diversion is 
located and during times of water emergency, such rights shall be filled from the allocations 
specified in article IV hereof for the section in which the point of diversion is located, with the 
exception that the diversion of water into the Hilliard East Fork Canal, Lannon Canal, Lone 
Mountain Ditch, and Hilliard West Side Canal shall be under the administration of Wyoming. 
During times of water emergency these canals and the Lone Mountain Ditch shall be supplied 
from the allocation specified in article IV for the Upper Wyoming section diversions."



Associated Storage Rights: 
Associated Storage Rights:





Reservoir
Shareholder
Volume 
(Acre-ft)		
Est. % of Shares Used this Diversion3
Comments



Whitney
Sharon Ruffi
90
100%




Whitney
Kyle Lowman
131.62
100%




Whitney
Sam Lowman
179
100%




Whitney
John Burton
111.38
100%







Irrigation Practices:  Land is all flood irrigated. 3


Estimated Diversion Efficiency: Canal losses are relatively high due to porous nature of soils in 
the higher reaches of the Upper Bear.  




Calculated Diversion Efficiency = Conveyance Efficiency X Application Efficiency:





Conveyance Efficiency: 45%


Application Efficiency: 55%


Overall Diversion Efficiency: 25%








Conveyance efficiency is estimated by total length of main canal.  Application efficiency 
for flood irrigation and sprinkler irrigation is estimated at 55% and 85% respectively.




Crop Types / Consumptive Use:  Water is used entirely to irrigate meadow grasses, primarily 
Timothy, Meadow Foxtail, etc.3


Return Flows:  Return flow is split between the Lewis Ditch (approx. 30%) and Mill Creek 
(approx. 70%).

The following return flow pattern was adopted for modeling in this study are as follows: 



	
			Month
		(after initial Diversion)	Percent of Return
			0				70%
			1				20%
			2				10%
			3				0%
							100%








click to enlarge


References:

    

  1. USDA -Soil Conservation Service Economic Research Service-Forest Service in Cooperation 
with the States of Idaho, Utah, Wyoming, Irrigation Conveyance Systems, Working Paper for 
the Bear River Basin Type IV Study, Idaho-Utah-Wyoming, April 1976

    

  2. Water rights summary obtained from State Engineer Interstate Reglist – revised April 14, 
1999

    

  3. Irrigation practices based on field investigation and interview with Mr. Don Shoemaker, 
Water Hydrographer-Commissioner  –  November 6,1999.

    

  4. State of Utah Natural Resources, Water Budget Studies – Utah, Bear River Study Area, 
September 1994
	





Monthly Diversion Records






YEAR
MAY
JUNE
JULY
AUGUST
SEPTEMBER



Total of Daily Ave for Month
Average
CFS		
Monthly Total
Ac-Ft		
Total of Daily Ave for Month
Average
CFS		
Monthly Total
Ac-Ft		
Total of Daily Ave for Month
Average
CFS		
Monthly Total
Ac-Ft		
Total of Daily Ave for Month
Average
CFS		
Monthly Total
Ac-Ft		
Total of Daily Ave for Month
Average
CFS		
Monthly Total
Ac-Ft



*1970
































1971
106
3.4
210.2
846
28.2
1678.0
550
17.7
1090.9
273
8.8
541.5
403
13.4
799.3



1972
298
9.6
591.1
913
30.4
1810.9
429
13.8
850.9
90
2.9
178.5
175
5.8
347.1



1973
135
4.4
267.8
717
23.9
1422.1
460
14.8
912.4
307
9.9
608.9
217
7.2
430.4



1974
244
7.9
484.0
621
20.7
1231.7
504
16.3
999.7
177
5.7
351.1
40
1.3
79.3



1975
56
1.8
111.1
768
25.6
1523.3
742
23.9
1471.7
224
7.2
444.3
291
9.7
577.2



1976
241
7.8
478.0
565
18.8
1120.7
244
7.9
484.0
51
1.6
101.2
513
17.1
1017.5



1977
174
5.6
345.1
239
8.0
474.0
46
1.5
91.2
0
0.0
0.0
64
2.1
126.9



1978
510
16.5
1011.6
666
22.2
1321.0
515
16.6
1021.5
176
5.7
349.1
130
4.3
257.9



1979
341
11.0
676.4
558
18.6
1106.8
291
9.4
577.2
103
3.3
204.3
136
4.5
269.8



1980
393
12.7
779.5
592
19.7
1174.2
474
15.3
940.2
164
5.3
325.3
69
2.3
136.9



1981
382
12.3
757.7
323
10.8
640.7
271
8.7
537.5
168
5.4
333.2
175
5.8
347.1



1982
319
10.3
632.7
503
16.8
997.7
548
17.7
1086.9
317
10.2
628.8
644
21.5
1277.4



1983
141
4.5
279.7
326
10.9
646.6
348
11.2
690.2
212
6.8
420.5
106
3.5
210.2



1984
346
11.2
686.3
542
18.1
1075.0
517
16.7
1025.5
131
4.2
259.8
21
0.7
41.7



1985
446
14.4
884.6
448
14.9
888.6
465
15.0
922.3
281
9.1
557.4
133
4.4
263.8



1986
146
4.7
289.6
520
17.3
1031.4
486
15.7
964.0
377
12.2
747.8
399
13.3
791.4



1987
388
12.5
769.6
443
14.8
878.7
319
10.3
632.7
175
5.6
347.1
171
5.7
339.2



1988
552
17.8
1094.9
944
31.5
1872.4
308
9.9
610.9
5
0.2
9.9
0
0.0
0.0



1989
606
19.5
1202.0
455
15.2
902.5
283
9.1
561.3
139
4.5
275.7
15
0.5
29.8



1990
409
13.2
811.2
564
18.8
1118.7
404
13.0
801.3
50
1.6
99.2
50
1.7
99.2



1991
273
8.8
541.5
479
16.0
950.1
380
12.3
753.7
106
3.4
210.2
87
2.9
172.6



1992
606
19.5
1202.0
305
10.2
605.0
185
6.0
366.9
186
6.0
368.9
3
0.1
6.0



1993
274
8.8
543.5
421
14.0
835.0
645
20.8
1279.3
444
14.3
880.7
609
20.3
1207.9



1994
599
19.3
1188.1
444
14.8
880.7
443
14.3
878.7
3
0.1
6.0
3
0.1
6.0



1995
345
11.1
684.3
441
14.7
874.7
501
16.2
993.7
293
9.5
581.2
404
13.5
801.3



1996
250
8.1
495.9
480
16.0
952.1
544
17.5
1079.0
359
11.6
712.1
180
6.0
357.0



1997
387.7
12.5
769.0
321.2
10.7
637.1
551
17.8
1092.9
302.4
9.8
599.8
271.7
9.1
538.9



1998
411.5
13.3
816.2
407.5
13.6
808.3
406
13.1
805.3
264.4
8.5
524.4
279
9.3
553.4



1999
146
4.7
289.6
383
12.8
759.7
432
13.9
856.9
257
8.3
509.8
195
6.5
386.8







AVERAGES


10.6
651.5


17.5
1042.0


13.7
840.6


6.3
385.4


6.6
395.6




Notes:

*1. No published records are available for this diversion 1970














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