Pueblo Reservoir, a component of the Fryingpan-Arkansas Project water supply system.

D&A staff has provided ongoing water resources consulting services to the Arkansas Groundwater Users Association (AGUA) since 1996. AGUA provides well augmentation water for approximately 400 wells located in the Arkansas Valley from Leadville to Las Animas.

D&A staff assists AGUA with the identification, evaluation and procurement of sources of replacement water either for purchase or for temporary use through leasing. Two feasibility studies have been prepared to support purchases of water right. D&A staff assisted the client by obtaining low interest funding through the Colorado Water Conservation Board (CWCB).

D&A staff prepares annual plans that provide the mechanism allowing continued use of AGUA member irrigation, commercial and domestic wells. Without the replacement plan to mitigate out-of-priority diversions to the Arkansas River and its tributaries, the wells would not be allowed to pump. The plans are prepared in accordance with rules established by the Division of Water Resources, State Engineer's Office.

In addition to preparing the initial plan, D&A staff manages the operation of the replacement plan throughout the plan year. D&A staff works with State personnel at the Division Engineer's Office in Pueblo, CO to assure that adequate replacement water is provided to offset any adverse water rights impacts due to well pumping.

Client: Arkansas Groundwater Users Association
Project Cost: On-going

Thornton – General Water Rights Consulting
City of Thornton, Colorado

D&A staff have provided the City of Thornton with general water rights consulting
services since 1983. Litigation support for Thornton 's new water rights filings and
litigation support as an objector to protect Thornton 's water rights has been provided.

Thornton Northern Water Supply Project
City of Thornton, Colorado

D&A staff previously conducted historic consumptive use analyses for 103 farms
acquired by the City of Thornton, provided groundwater modeling, conducted Poudre
River basin modeling, provided raw water system planning, and provided litigation
support for water rights applications as part of Thornton 's Northern Water Supply Project.

The City of Thornton began acquiring farms and water rights in Northern Colorado in 1985 to meet future water demands. D&A staff conducted several engineering studies to assist the City in transferring the water rights to municipal use.

The engineering studies included an historic consumptive use analysis and return flow analysis for irrigation water applied to each of the 103 farms acquired by the City of Thornton.

D&A staff conducted a phased study of groundwater and surface water flow regimes and interactions in the Lower Cache la Poudre River basin. The study consisted of groundwater modeling, including analysis of existing and projected water quality impacts. D&A staff installed and designed monitoring wells, conducted aquifer tests, compiled surface and subsurface geologic data, constructed isopach structure contour and potentiometric surface maps, and implemented a detailed data base management system.

D&A staff conducted a project completion study to determine the most efficient way to deliver water from the Poudre basin to Thornton. The Project Completion Study involved: 1) determining project yields, 2) assessing present and future water demands, 3) determining project components, 4) estimating project costs, and 5) developing an augmentation plan.

D&A staff provided litigation support, including extensive expert witness testimony during the 55-day trial. A decree was awarded to Thornton that will provide an average annual raw water supply of 56,800 acre-feet.

Client: City of Thornton

Thornton/Westminster/Coors Agreement
City of Thornton, Colorado

D&A staff conducted an investigation of an exchange plan that resolved water
quality disputes between the City of Thornton, City of Westminster, and City
of Golden involving Clear Creek water. A Clear Creek model was developed to
include the components of the exchange plan. Water rights litigation support
was provided to facilitate the agreement between the parties.

The City of Thornton, as an owner of water rights in Standley Lake, was concerned about the water quality impacts due to delivery of Coors and Golden sewage effluent upstream of the Standley Lake inlet in the winter. D&A staff examined several alternatives to mitigate the water quality problems. The investigations focused on a plan that prevents the Coors and Golden sewage effluent from lowering the excellent water quality found in Standley Lake.

D&A staff worked with engineers from the City of Westminster, City of Thornton, and Coors to develop the exchange plan that was acceptable to all parties. Once the exchange plan was conceptually agreed upon, a computer model was developed to simulate the exchange plan. An existing Clear Creek basin water rights model was modified to include Thornton's raw water operations and other operations necessary to simulate the exchange plan. The model was tested, calibrated, and verified before it was applied to various exchange plan scenarios.

Preliminary cost estimates for storage facilities, pump stations, pipelines, and rights-of-way were provided as part of the investigation. The cost estimates were utilized in the agreement formed between the parties.

D&A staff provided general consulting to Thornton in regard to the agreement and water rights assistance to the subsequent water rights filings made in support of the agreement that was litigated in Case No. 88CW268.

Client: City of Thornton

Central City Water Resources Engineering
Central City, Colorado

Chase Gulch Reservoir, a component of Central City's water supply system
located on Chase Gulch, a tributary of North Clear Creek

D&A staff have provided on-going water resources consulting services to Central City since 1995. Services have included extensive water right analyses and litigation support for various types of water rights issues, including exchanges on Clear Creek and North Clear Creek, claims for reusable lawn irrigation return flows, plan for augmentation, and applications for junior conditional direct flow and storage water rights.

In addition, D&A staff have reviewed applications for water rights of a number of other water users on Clear Creek to ensure that no injury would result to Central City's water rights.

D&A staff developed a computer operations model of the Central City raw water supply system. The model included the operation of water rights on North Clear Creek and tributaries of North Clear Creek, water rights on Fall River, and exchange of Central City's Farmers' Highline shares from the Farmers' Highline augmentation station up to various points of diversion on North Clear Creek and its tributaries.

D&A staff also provided feasibility analysis, design, and construction engineering services for Chase Gulch Dam and Reservoir.

Client: City of Central

Water resources planning for the City of Longmont has been provided by D&A staff since 1982, including water rights litigation support, engineering design, and construction observation.

D&A staff have provided the City of Longmont with water resources planning services since 1982. D&A staff have conducted analyses of future raw water demands, evaluated the yield of the City's raw water supplies, compared future drought demands with raw water supplies to determine the adequacy of the City's raw water supply system, and evaluated alternatives for future raw water supplies. A raw water master plan was also developed for the City.

D&A staff has provided water rights litigation support for numerous City water rights applications. These applications included: changes of use from irrigation to municipal use, changes of use from direct flow to storage, changes in place of storage for storage decrees, new storage appropriations and quantification of the timing, amount, and location of lawn irrigation return flows within the City.

The largest of these projects was a water rights change of use for six irrigation ditches resulting in the successful transfer of 7,000 acre-feet per year.

D&A staff assisted in the settlement negotiations associated with these water rights applications.

Additional services include: design and construction observation to the City of Longmont for numerous transmission and distribution pipelines, sanitary sewer lines and dams.

Client: City of Longmont

Development of a spreadsheet model to evaluate the City of Thornton 's
Clear Creek exchange potential in Case No. 83CW081. Litigation
support, including expert witness testimony, was provided by D&A
staff to assist Thornton in obtaining a decree from the Water Court.

The City of Thornton previously owned water rights in South Park and a significant interest in the Burlington / Wellington system. To add operational flexibility to Thornton 's raw water delivery system, the City sought to exchange their South Platte River water up Clear Creek to the Lower Clear Creek Ditch headgate, which feeds the West Gravel Lakes and to the Church Ditch, Croke Canal, and Farmers High Line Canal headgates which feed Standley Lake. A point flow spreadsheet model was developed by D&A staff to determine the exchange potential on Clear Creek. The Clear Creek point flow model included the stream flows, diversions, and tributary inflows from the South Platte River confluence to the Clear Creek at Golden gage. The results of the spreadsheet model were utilized to support Thornton 's Clear Creek exchange filing in Case No. 83CW081, including negotiations with objectors, preparation of Court exhibits, participation in depositions, and providing expert witness testimony. The District Court in Water Division 1 awarded Thornton the right to exchange water from the South Platte River to Clear Creek in Case No. 83CW081.

Client: City of Thornton

Lake Erie Transfer
City of Thornton, Colorado

D&A staff assisted the City of Thornton in transferring 80 percent of the Lake Erie
Water right from irrigation use to municipal uses in Case No. 82CW222.
Expert witness testimony was provided by D&A personnel.

The City of Thornton acquired 80 percent of Lake Erie in 1980. Lake Erie is a 302 acre-foot reservoir that is located just north of Eastlake, Colorado. Lake Erie was historically filled with Clear Creek water. The Farmers High Line Canal and Signal Ditch delivered Clear Creek water to Lake Erie. Lake Erie water was used as a supplemental irrigation water supply.

The City of Thornton transferred the Lake Erie water from irrigation use to municipal uses and changed the location of storage to Standley Lake. D&A staff performed a consumptive use analysis and an analysis of the timing, location, and amount of return flows. D&A staff provided litigation support for Thornton in the transfer of Lake Erie water in Case No. 82CW222. Expert witness testimony was provided, as well as preparation of Court exhibits, negotiations with objectors, and deposition participation. A decree was awarded to the City of Thornton.

Client: City of Thornton

Prairie Ditch and San Luis Valley Canal
San Luis Valley, Colorado

The lands served by the Prairie Ditch and San Luis Valley Canal lie largely within what is known as the “ Closed Basin.” The Closed Basin occupies the northern portion of the San Luis Valley, and is separated from the Rio Grande 's alluvial valley by a low topographic divide and a shallow groundwater divide oriented roughly parallel to the river. Water imported into the Closed Basin does not naturally return to the Rio Grande.

The Prairie Ditch and the San Luis Valley Canal Companies recognize that continued importation of direct flow surface water from the Rio Grande, in conjunction with groundwater recharge, is crucial to sustaining the shallow groundwater reservoir that allows the continuing operation of their center pivot sprinkler systems. To this end, Company shareholders have constructed groundwater recharge facilities to artificially recharge groundwater.

D&A staff performed an investigation of the historical water use practiced by the Prairie Ditch and San Luis Valley Canal Companies. The objectives of this investigation were to confirm their historic practice of recharging the unconfined aquifer of the Closed Basin, and to present a methodology and accounting procedure to quantify the volume of recharge to the unconfined aquifer of the Closed Basin from their water rights.

D&A staff also performed a hydrologic analysis of the Closed Basin, updating the location of the groundwater divide. D&A staff provided expert witness testimony on the Prairie Ditch Case, which was settled in late-2001. The San Luis Valley Canal Case is currently pending.

Client: Prairie Ditch Company and San Luis Valley Canal Company
Project Cost: $100,000

Pueblo Water Resources Engineering
Pueblo, Colorado

Pueblo Reservoir, a component of the Board of Water Works water supply system.

D&A staff has provided ongoing water resources consulting services to the Board of Water Works since 1985. The Board provides water to approximately 110,000 people living in the City of Pueblo, Colorado.

Services have included extensive water rights analyses and litigation support for various types of water rights issues including river exchanges, changes of use from irrigation to municipal use, changes of use from direct flow to storage, claims for reusable lawn irrigation return flows, plans for augmentation and water quality analyses.

The analysis of lawn irrigation return flows included development of a MODFLOW groundwater model of the Pueblo service area and vicinity.

D&A staff developed a computer operations model of Pueblo 's raw water supply system. The model included the operation of water rights on the Arkansas River from the headwaters near Leadville, Colorado, down to John Martin Reservoir.

The model has been used to analyze the yield of Pueblo 's entire system, yield of exchange operations and analysis of competing water rights. D&A staff have also provided feasibility analysis, design and construction engineering services for the rehabilitation of three of Pueblo 's transmountain diversion canals: the Ewing, Columbine and Wurtz Ditches.

Client: Board of Water Works of Pueblo, Colorado

Rio Grande Project
Elephant Butte Dam and Reservoir, New Mexico

Competing interests among irrigators, cities, states, and nations in the
Rio Grande Valley creates and incredibly complex water supply scenario.

The Rio Grande Project furnishes an irrigation water supply for about 178,000 acres of land in the Rio Grande Valley in New Mexico and Texas. The project also supplies electric power for communities and industries in the area. The primary storage reservoir is Elephant Butte Reservoir with a capacity of 2,210,000 acre-feet.

D&A staff has provided engineering technical assistance to the Department of Justice and Bureau of Reclamation to resolve water rights and operational issues that have developed as part of a water rights litigation involving the Bureau of Reclamation, State of Colorado, State of New Mexico, State of Texas, International Compact Commission, Elephant Butte Irrigation District, El Paso County Water Improvement District No. 1, and other water users within the Rio Grande Project.

D&A staff conducted surface water hydrologic investigations, development of an operating plan, analyses of Rio Grande Project yields, analyses of Rio Grande Compact issues, analyses of water quality impacts and negotiations with other parties to assist in the settlement of their water rights litigation. D&A staff is expected to provide expert witness testimony should the on-going litigation proceed to trial.

Client: United States Department of Justice
Project Cost: $150,000 (engineering)

South Platte Gravel Pit Storage System
City of Thornton, Colorado

The City of Thornton identified the need for 30,000 acre-feet of South Platte River
storage between Thornton and Greeley, Colorado. D&A staff assisted the City of
Thornton in identifying gravel pit storage sites, conducting feasibility studies of the pits,
filing water rights applications, and providing litigation support in Water Court.

The City of Thornton identified a need for approximately 30,000 acre-feet of South Platte River storage to implement its Northern Project. Prior to Thornton 's Northern Project coming on-line, the City developed a plan for use of South Platte River storage. The plan includes storage of the reusable portion of water generated by potable water use within the City, storage of consumptive use water owned or controlled by the City that cannot be immediately used within the City, and storage of a new water right. The water stored in the South Platte gravel pits would either be exchanged upstream to Thornton facilities and used at the water treatment plants or pumped directly to the water treatment plants.

D&A staff assisted in field surveys, posted signs at the new points of diversion and storage, and assisted in preparation of the Water Court application in Case No. 91CW126. D&A staff provided litigation support for the application, including expert witness testimony.

D&A staff assisted in the development of a plan for exchange of the water stored in the South Platte gravel pits to raw water storage facilities near the City's water treatment plants. D&A staff aided the City in their South Platte River exchange application filed in Case No. 96CW1116, and in negotiating a settlement with objectors in this case. A decree has been obtained by Thornton in this case.

D&A staff researched the Division of Minerals and Geology (previously known as the Mined Land Reclamation Board) records and conducted field investigations to identify suitable gravel pit storage sites. Based on this information, volumes at 12 gravel pit storage sites were estimated. A computer model was developed and operated to estimate the volume of water that could be stored in each of these reservoirs under a 1991 water right appropriation.

Client: City of Thornton