C.R.S. Section 37-68-101
Amended Costilla Creek compact

The general assembly hereby ratifies the amended compact between the state of Colorado and the state of New Mexico, designated as the “Amended Costilla Creek Compact”, signed in the city of Santa Fe, state of New Mexico, on the seventh day of February, A. D. 1963, by J. E. Whitten, commissioner for the state of Colorado, and S. E. Reynolds, commissioner for the state of New Mexico, which said amended compact is as follows:

Amended Costilla Creek Compact

The state of Colorado and the state of New Mexico, parties signatory to this compact (hereinafter referred to as “Colorado” and “New Mexico,” respectively, or individually as a “state,” or collectively as the “states”), having on September 30, 1944 concluded, through their duly authorized commissioners, to-wit: Clifford H. Stone for Colorado and Thomas M. McClure for New Mexico, a compact with respect to the water of Costilla Creek, an interstate stream, which compact was ratified by the states in 1945 and was approved by the congress of the United States in 1946; and

The states, having resolved to conclude an amended compact with respect to the waters of Costilla Creek, have designated, pursuant to the acts of their respective legislatures and through their appropriate executive agencies, as their commissioners:

J. E. Whitten, for Colorado

S. E. Reynolds, for New Mexico

who, after negotiations, have agreed upon these articles:

Article I

The major purposes of this compact are to provide for the equitable division and apportionment of the use of the waters of Costilla Creek; to promote interstate comity; to remove causes of present and future interstate controversies; to assure the most efficient utilization of the waters of Costilla Creek; to provide for the integrated operation of existing and prospective irrigation facilities on the stream in the two states; to adjust the conflicting jurisdictions of the two states over irrigation works and facilities diverting and storing waters in one state for use in both states; to equalize the benefits of water from Costilla Creek, used for the irrigation of contiguous lands lying on either side of the Boundary, between the citizens and water users of one state and those of the other; and to place the beneficial application of water diverted from Costilla Creek for irrigation by the water users of the two states on a common basis.

The physical and other conditions peculiar to the Costilla Creek and its basin, and the nature and location of the irrigation development and the facilities in connection therewith, constitute the basis for this compact; and neither of the States hereby, nor the Congress of the United States by its consent, concedes that this compact establishes any general principle or precedent with respect to any other interstate stream.

Article II

As used in this compact, the following names, terms and expressions are described, defined, applied and taken to mean as in this article set forth:

(a)

“Costilla Creek” is a tributary of the Rio Grande which rises on the west slope of the Sangre de Cristo range in the extreme southeastern corner of Costilla County in Colorado and flows in a general westerly direction crossing the boundary three times above its confluence with the Rio Grande in New Mexico.

(b)

The “Canyon Mouth” is that point on Costilla Creek in New Mexico where the stream leaves the mountains and emerges into the San Luis Valley.

(c)

The “Amalia Area” is that irrigated area in New Mexico above the Canyon Mouth and below the Costilla Reservoir which is served by decreed direct flow water rights.

(d)

The “Costilla-Garcia Area” is that area extending from the Canyon Mouth in New Mexico to a point in Colorado about four miles downstream from the boundary, being a compact body of irrigated land on either side of Costilla Creek served by decreed direct flow water rights.

(e)

The “Eastdale Reservoir No. 1” is that off-channel reservoir located in Colorado in sections 7, 8 and 18, township 1 north, range 73 west, and sections 12 and 13, township 1 north, range 74 west, of the Costilla Estates survey, with a nominal capacity of three thousand four hundred sixty-eight (3,468) acre-feet and a present usable capacity of two thousand (2,000) acre-feet.

(f)

The “Eastdale Reservoir No. 2” is that off-channel reservoir located in Colorado in sections 3, 4, 9 and 10, township 1 north, range 73 west, of the Costilla Estates survey, with nominal capacity of three thousand forty-one (3,041) acre-feet.

(g)

The “Costilla Reservoir” is that channel reservoir, having a nominal capacity of fifteen thousand seven hundred (15,700) acre-feet, located in New Mexico near the headwaters of Costilla Creek. The present usable capacity of the reservoir is eleven thousand (11,000) acre-feet, subject to future adjustment by the state engineer of New Mexico. The condition of Costilla Dam may be such that the state engineer of New Mexico will not permit storage above a determined stage except for short periods of time.

(h)

The “Cerro Canal” is that irrigation canal which diverts water from the left bank of Costilla Creek in New Mexico near the southwest corner of section 12, township 1 south, range 73 west, of the Costilla Estates survey, and runs in a northwesterly direction to the boundary near Boundary Monument No. 140.

(i)

The “boundary” is the term used herein to describe the common boundary line between Colorado and New Mexico.

(j)

The term “Costilla Reservoir System” means and includes the Costilla Reservoir and the Cerro Canal, the permits for the storage of water in Costilla Reservoir, the twenty-four and fifty-two hundredths (24.52) cubic feet per second of time of direct flow water rights transferred to the Cerro Canal, and the permits for the diversion of direct flow water by the Cerro Canal as adjusted herein to seventy-five and forty-eight hundredths (75.48) cubic feet per second of time.

(k)

The term “Costilla Reservoir System Safe Yield” means that quantity of usable water made available each year by the Costilla Reservoir System. The safe yield represents the most beneficial operation of the Costilla Reservoir System through the use, first, of the total usable portion of the yield of the twenty-four and fifty-two hundredths (24.52) cubic feet per second of time of direct flow rights transferred to the Cerro Canal, second, of the total usable portion of the yield of the direct flow Cerro Canal permits, and third, of that portion of the water stored in Costilla Reservoir required to complete such safe yield.

(l)

The term “usable capacity” is defined and means that capacity of Costilla Reservoir at the stage above which the state engineer of New Mexico will not permit storage except for short periods of time.

(m)

The term “temporary storage” is defined and means the water permitted by the state engineer of New Mexico to be stored in Costilla Reservoir for short periods of time above the usable capacity of that reservoir.

(n)

The term “additional storage facilities” is defined and means storage capacity which may be provided in either state to impound waters of Costilla Creek and its tributaries in addition to the nominal capacity of Costilla Reservoir and the Costilla Creek complement of the Eastdale Reservoir No. 1 capacity.

(o)

The term “duty of water” is defined as the rate in cubic feet per second of time at which water may be diverted at the headgate to irrigate a specified acreage of land during the period of maximum requirement.

(p)

The term “surplus water” is defined and means water which cannot be stored in operating reservoirs during the storage season or water during the irrigation season which cannot be stored in operating reservoirs and which is in excess of the aggregate direct flow rights and permits recognized by this compact.

(q)

The term “irrigation season” is defined and means that period of each calendar year from May 16 to September 30, inclusive.

(r)

The term “storage season” is defined and means that period of time extending from October 1 of one year to May 15 of the succeeding year, inclusive.

(s)

The term “points of interstate delivery” means and includes (1) the Acequia Madre where it crosses the boundary; (2) the Costilla Creek where it crosses the boundary; (3) the Cerro Canal where it reaches the boundary; and (4) any other interstate canals which might be constructed with the approval of the commission at the point or points where they cross the boundary.

(t)

The term “water company” means The San Luis Power and Water Company, a Colorado corporation, or its successor.

(u)

The word “commission” means the Costilla Creek Compact commission created by Article VIII of this compact for the administration thereof.

Article III

1.

To accomplish the purposes of this compact, as set forth in Article I, the following adjustments in the operation of irrigation facilities on Costilla Creek, and in the use of water diverted, stored and regulated thereby, are made:

(a)

The quantity of water delivered for use in the two states by direct flow ditches in the Costilla-Garcia Area and by the Cerro Canal is based on a duty of water of one cubic foot per second of time for each eighty (80) acres, to be applied in the order of priority; provided, however, that this adjustment in each instance is based on the acreage as determined by the court in decreeing the water rights for the Costilla-Garcia Area, and in the case of the Cerro Canal such basis shall apply to eight thousand (8,000) acres of land. In order to better maintain a usable head for the diversion of water for beneficial consumptive use the adjusted maximum diversion rate under the water right of each of the ditches supplying water for the Costilla-Garcia Area in Colorado is not less than one cubic foot per second of time.

(b)

There is transferred from certain ditches in the Costilla-Garcia Area twenty-four and fifty-two hundredths (24.52) cubic feet per second of time of direct flow water rights, which rights of use are held by the water company or its successors in title, to the headgate of the Cerro Canal. The twenty-four and fifty-two hundredths (24.52) cubic feet of water per second of time hereby transferred represents an evaluation of these rights after adjustment in the duty of water, pursuant to subsection (a) of this Article, and includes a reduction thereof to compensate for increased use of direct flow water which otherwise would have been possible under these rights by this transfer.

(c)

Except for the rights to store water from Costilla Creek in Eastdale Reservoir No. 1 as hereinafter provided, all diversion and storage rights from Costilla Creek for Eastdale Reservoirs No. 1 and No. 2 are relinquished and the water decreed thereunder is returned to the creek for use in accordance with the plan of integrated operation effectuated by this compact.

(d)

The Cerro Canal direct flow permit shall be seventy-five and forty-eight hundredths (75.48) cubic feet per second of time.

(e)

There is transferred to and made available for the irrigation of lands in Colorado a portion of the Costilla Reservoir complement of the Costilla Reservoir System Safe Yield in order that the storage of water in that reservoir may be made for the benefit of water users in both Colorado and New Mexico under the provisions of this compact for the allocations of water and the operation of facilities.

2.

Each state grants for the benefit of the other and its water users the rights to change the points of diversion of water from Costilla Creek, to divert water from the stream in one state for use in the other and to store water in one state for the irrigation of lands in the other, insofar as the exercise of such rights may be necessary to effectuate the provisions of this Article and to comply with the terms of this compact.

3.

The water company has consented to and approved the adjustments contained in this Article; and such consent and approval shall be evidenced in writing and filed with the commission.

Article IV

The apportionment and allocation of the use of Costilla Creek water shall be as follows:

(a)

There is allocated for diversion from the natural flow of Costilla Creek and its tributaries sufficient water for beneficial use on meadow and pasture lands above Costilla Reservoir in New Mexico to the extent and in the manner now prevailing in that area.

(b)

There is allocated for diversion from the natural flow of Costilla Creek and its tributaries thirteen and forty-two hundredths (13.42) cubic feet of water per second of time for beneficial use on lands in the Amalia Area in New Mexico.

(c)

In addition to allocations made in subsections (e), (f) and (g) of this Article, there is allocated for diversion from the natural flow of Costilla Creek fifty and sixty-two hundredths (50.62) cubic feet of water per second of time for Colorado and eighty-nine and eight hundredths (89.08) cubic feet of water per second of time for New Mexico, subject to adjustment as provided in Article V (e), and such water shall be delivered for beneficial use in the two states in accordance with the schedules and under the conditions set forth in Article V.

(d)

There is allocated for diversion from the natural flow of Costilla Creek sufficient water to provide each year one thousand (1,000) acre-feet of stored water in Eastdale Reservoir No. 1, such water to be delivered as provided in Article V.

(e)

There is allocated for diversion to Colorado thirty-six and five-tenths per cent (36.5%) and to New Mexico sixty-three and five-tenths per cent (63.5%) of the water stored by Costilla Reservoir for release therefrom for irrigation purposes each year, subject to adjustment as provided in Article V (e) and such water shall be delivered for beneficial use in the two states on a parity basis in accordance with the provisions of Article V. By “parity basis” is meant that neither state shall enjoy a priority of right of use.

(f)

There is allocated for beneficial use in each of the states of Colorado and New Mexico one-half of the surplus water, as defined in Article II (p), to be delivered as provided in Article V.

(g)

There is allocated for beneficial use in each of the states of Colorado and New Mexico one-half of any water made available and usable by additional storage facilities which may be constructed in the future.

Article V

The operation of the facilities of Costilla Creek and the delivery of water for the irrigation of land in Colorado and New Mexico, in accordance with the allocations made in Article IV, shall be as follows:

(a)

Diversions of water for use on lands in the Amalia Area shall be made as set forth in Article IV (b) in the order of decreed priorities in New Mexico and of relative priority dates in the two states, subject to the right of New Mexico to change the points of diversion and places of use of any of such water to other points of diversion and places of use; provided, however, that the rights so transferred shall be limited in each instance to the quantity of water actually consumed on the lands from which the right is transferred.

(b)

Deliveries to Colorado of direct flow water below the Canyon Mouth shall be made by New Mexico in accordance with the following schedule:

Deliveries of Direct Flow Water to Colorado During Irrigation Season

UsableIncrementalPoints ofCumulativeRemarks

DischargeAllocationsInterstateAllocations

of Creek atto ColoradoDeliveryto Colorado

Canyon

(C.F.S.)

Intentionally left blank —Ed.

(C.F.S.)

Mouth

Gaging

Station

(C.F.S.)(1)(2A)(2B)(3)(4)(5) 25.001.05AcequiaIncremental allocation is 4.2%

Madreof the usable discharge when

usable discharge is less than

25.00 C.F.S.

2.53Cerro

CanalIncremental allocation is 10.13%

of the usable discharge when

usable discharge is less than

25.00 C.F.S.

4.70Cerro

Canal8.28This 4.70 C.F.S. is not a part

of the Colorado allocation of

the direct flow water of the

Costilla Reservoir System

and is not subject to

adjustment in the event of

a change in the usable

capacity of Costilla Reservoir.

Incremental allocation is

18.8% of the usable discharge

when usable discharge is less

than 25.00 C.F.S. This 4.70

C.F.S. allocated to Colorado

for delivery through the Cerro

Canal is 5.50 C.F.S. of the

original 6.55 C.F.S. allocated

to Colorado for delivery

through the Acequia Madre

less 0.8 C.F.S. correction for

losses.

36.88.38Cerro

CanalThis 0.38 C.F.S. is not a part

of the Colorado allocation

of the direct flow water of

the Costilla Reservoir System

and is not subject to adjustment

in the event of a change in the

usable capacity of Costilla

Reservoir. Incremental

allocation is 3.26% of the

usable discharge in excess

of 25.38 C.F.S. and less

than 36.88 C.F.S.

4.04Cerro

Canal12.70Incremental allocation is

35.11% of the usable discharge

in excess of 25.38 C.F.S. and

less than 36.88 C.F.S.

38.621.00Creek13.70Incremental allocation is

100% of the usable discharge

in excess of 37.62 C.F.S. and

less than 38.62 C.F.S.

44.762.24Cerro

Canal15.94Incremental allocation is

36.5% of the usable discharge

in excess of 38.62 C.F.S. and

less than 44.76 C.F.S.

50.916.00Creek21.94Incremental allocation is

100% of the usable discharge

in excess of 44.91 C.F.S. and

less than 50.91 C.F.S.

56.48.13Cerro

Canal22.07Incremental allocation is

11.18% of the usable discharge

in excess of 55.35 C.F.S. and

less than 56.48 C.F.S.

61.481.00Creek23.07Incremental allocation is

100% of the usable discharge

in excess of 60.48 C.F.S. and

less than 61.48 C.F.S.

64.22At usable creek discharge of

64.22 C.F.S. the Cerro Canal

direct flow permit becomes

operative after 1,000 acre-feet

has been stored in Eastdale

Reservoir No. 1.

139.7027.55Cerro

Canal50.62Incremental allocation is

36.5% of the usable discharge

in excess of 64.22 C.F.S. and

less than 139.70 C.F.S.

The actual discharges of Costilla Creek at the Canyon Mouth Gaging Station at which the various blocks of direct flow water become effective shall equal the flows set forth in column (1) increased by the transmission losses necessary to deliver those flows to the headgates of the respective direct flow ditches diverting in New Mexico.

The delivery of ditch water at the boundary shall equal the allocation set forth in columns (2a) and (2b) reduced by the transmission losses between the headgate of the ditch and the point where the ditch crosses the boundary. The allocations to be delivered to Colorado through the Cerro Canal represent, except as otherwise indicated in column (5) of the table above, 36.5 percent of those blocks of direct flow water of the Costilla Reservoir System which are subject to adjustment as provided in subsection (e) of this article.

The provisions of article III (1)(a) shall not be applicable to the Colorado allocation of 5.08 C.F.S. which is transferred from the Acequia Madre to the Cerro Canal by this amendment to the Costilla Creek compact and shall not be applicable to the 0.8 C.F.S. which is transferred from Colorado to New Mexico by this amendment to the Costilla Creek compact.

The above table is compiled on the basis of the delivery to Colorado at the boundary of thirty-six and five-tenths percent (36.5%) of all direct flow water of the Costilla Reservoir System diverted by the Cerro Canal and the delivery at the boundary of all other direct flow water allocated to Colorado, in the order of priority, all such deliveries to be adjusted for transmission losses. In the event of change in the usable capacity of the Costilla Reservoir, Colorado’s share of all direct flow water of the Costilla Reservoir System diverted by the Cerro Canal, to be delivered at the boundary and adjusted for transmission losses, shall be determined by the percentages set forth in column (4) of the table which appears in subsection (e) of this article.

(c)

During the storage season, no water shall be diverted under direct flow rights unless there is water in excess of the demand of all operating reservoirs for water from Costilla Creek for storage.

(d)

In order to assure the most efficient utilization of the available water supply, the filling of Eastdale Reservoir No. 1 from Costilla Creek shall be commenced as early in the spring as possible and shall be completed as soon thereafter as possible. The Cerro Canal or any other ditch which may be provided for that purpose shall be used, insofar as practicable, to convey the water from the Canyon Mouth to Eastdale Reservoir No. 1. During any season when the commission determines that there will be no surplus water, any diversions, waste or spill from any canal or canals supplying Eastdale Reservoir No. 1 will be charged to the quantity of water diverted for delivery to said reservoir.

(e)

The commission shall estimate each year the safe yield of Costilla Reservoir System and its component parts as far in advance of the irrigation season as possible, and shall review and revise such estimates from time to time as may be necessary.

In the event the usable capacity of the Costilla Reservoir changes, the average safe yield and the equitable division thereof between the states shall be determined in accordance with the following table:

UsableAverage

CapacityAnnualDivision of Safe Yield

of CostillaSafe YieldColoradoNew Mexico

Reservoir(acre-feet)(acre-feet)(percent)(acre-feet)(percent)

(1)(2)(3)(4) (5)(6) 0

1,8001,51083.9

290 16.1

1,000

3,4002,00058.8

1,400 41.2

2,000

4,9002,45050.0

2,450 50.0

3,000

6,4002,91045.5

3,490 54.5

4,000

7,9003,37042.7

4,530 57.3

5,000

9,3003,80040.9

5,500 59.1

6,00010,700

4,22039.4

6,48060 . 6

7,00012,000

4,62038.5

7,38061 . 5

8,00013,200

4,99037.8

8,21062 . 2

9,00014,300

5,32037.2

8,98062 . 8

10,00015,200

5,60036.8

9,60063.2

11,00016,000

5,84036.510,16063.5

12,00016,600

6,02036.310,58063.7

13,00017,000

6,14036.110,86063.9

14,00017,400

6,27036.011,13064.0

15,00017,700

6,36035.911,34064.1

15,70017,900

6,42035.911,48064.1

Intermediate quantities shall be computed by proportionate parts.

In the event of change in the usable capacity of the Costilla Reservoir, the Costilla Reservoir complement of the Costilla Reservoir System Safe Yield shall be divided between Colorado and New Mexico in accordance with the percentages given in columns 4 and 6, respectively, of the above table.

Each state may draw from the reservoir in accordance with the allocations made herein, up to its proportion of the Costilla Reservoir complement of the Costilla Reservoir System Safe Yield and its proportion of temporary storage and no more. Colorado may call for the delivery of its share thereof at any of the specified points of interstate delivery.

Deliveries of water from Costilla Reservoir to the Canyon Mouth shall be adjusted for transmission losses, if any, between the two points. Deliveries to Colorado at the boundary shall be further adjusted for transmission losses from the Canyon Mouth to the respective points of interstate delivery.

Water stored in Costilla Reservoir and not released during the current season shall not be held over to the credit of either state but shall be apportioned when the safe yield is subsequently determined.

(f)

The Colorado apportionment of surplus water, as allocated in Article IV (f), shall be delivered by New Mexico at such points of interstate delivery and in the respective quantities, subject to transmission losses, requested by the Colorado member of the commission.

(g)

In the event that additional water becomes usable by the construction of additional storage facilities, such water shall be made available to each state in accordance with rules and regulations to be prescribed by the commission.

(h)

When it appears to the commission that any part of the water allocated to one state for use in a particular year will not be used by that state, the commission may permit its use by the other state during that year, provided that a permanent right to the use of such water shall not thereby be established.

Article VI

The desirability of consolidating various of the direct flow ditches serving the Costilla-Garcia Area, which are now or which would become interstate in character by consolidation, and diverting the water available to such ditches through a common headgate is recognized. Should the owners of any of such ditches, or a combination of them, desire to effectuate a consolidation and provide for a common headgate diversion, application therefor shall be made to the commission which, after review of the plans submitted, may grant permission to make such consolidation.

Article VII

The commission shall cause to be maintained and operated a streamgaging-station, equipped with an automatic water-stage recorder, at each of the following points, to-wit:

(a)

On Costilla Creek immediately below Costilla Reservoir.

(b)

On Costilla Creek at or near the Canyon Mouth above the headgate of Cerro Canal and below the Amalia Area.

(c)

On Costilla Creek at or near the boundary.

(d)

On the Cerro Canal immediately below its headgate.

(e)

On the Cerro Canal at or near the boundary.

(f)

On the intake from Costilla Creek to the Eastdale Reservoir No. 1, immediately above the point where the intake discharges into the reservoir.

(g)

On the Acequia Madre immediately below its headgate.

(h)

On the Acequia Madre at the boundary.

(i)

Similar gaging stations shall be maintained and operated at such other points as may be necessary in the discretion of the commission for the securing of records required for the carrying out of the provisions of the compact.

Such gaging stations shall be equipped, maintained, and operated by the commission directly or in cooperation with an appropriate federal or state agency, and the equipment, method, and frequency of measurement at such stations shall be such as to produce reliable records at all times.

Article VIII

The two states shall administer this compact through the official in each state who is now or may hereafter be charged with the duty of administering the public water supplies, and such officials shall constitute the Costilla Creek Compact Commission. In addition to the powers and duties hereinbefore specifically conferred upon such commission, the commission shall collect and correlate factual data and maintain records having a bearing upon the administration of this compact. In connection therewith, the commission may employ such engineering and other assistance as may be reasonably necessary within the limits of funds provided for that purpose by the states. The commission may, by unanimous action, adopt rules and regulations consistent with the provisions of this compact to govern its proceedings. The salaries and expenses of the members of the commission shall be paid by their respective states. Other expenses incident to the administration of the compact, including the employment of engineering or other assistance and the establishment and maintenance of compact gaging stations, not borne by the United States shall be assumed equally by the two states and paid directly to the commission upon vouchers submitted for that purpose.

The United States geological survey, or whatever federal agency may succeed to the functions and duties of that agency, shall collaborate with the commission in the correlation and publication of water facts necessary for the proper administration of this compact.

Article IX

This amended compact shall become operative when ratified by the legislatures of the signatory states and consented to by the Congress of the United States; provided, that, except as changed herein, the provisions, terms, conditions and obligations of the Costilla Creek Compact executed on September 30, 1944, continue in full force and effect.

IN WITNESS WHEREOF, the commissioners have signed this compact in triplicate original, one copy of which shall be deposited in the archives of the department of state of the United States of America, and one copy of which shall be forwarded to the governor of each of the signatory states.

Done in the city of Santa Fe, New Mexico, on the 7th day of February, in the year of our Lord, one thousand nine hundred and sixty-three.

(Signed)

J. E. Whitten,

Commissioner for Colorado.

(Signed)

S. E. Reynolds,

Commissioner for New Mexico.