News & Information
River Basin Plans
Basin Advisory Groups
SNAKE/SALT RIVER BASIN PLAN
SCOPE OF SERVICES
The 2001 Legislature authorized the Wyoming Water Development Commission to complete
the Snake/Salt River Basin portion of the State Water Plan. The Consultant will complete the
tasks and requirements outlined in this document.
B. PROJECT DESCRIPTION
1. Location. The project is located in all or portions of Fremont,
Lincoln, Sublefte, and Teton Counties, Wyoming. This includes the portions of those
counties in Yellowstone National Park.
2. Purpose. The project will include the preparation of a
basin plan for the Snake and Salt River Basins in Wyoming. All data collected and
provided by the Consultant must be compatible with applicable data standards
established by the Water Development Commission for the State Water Plan, with the
database requirements of the Water Resources Data System, Department of Civil and
Architectural Engineering at the University of Wyoming, College of Engineering, and
with the Wyoming Office of Geographic Information Systems.
3. History. The 1996 Wyoming Legislature authorized the
Wyoming Water Development Commission (WWDC) and the State Engineer's Office
(SEO) to prepare a proposal for updating the 1973 Framework Water Plan. In 1997, the
Legislature appropriated funds for a water planning feasibility study. The WWDC and
the SEO chose the Bear River Basin as a pilot area to test planning assumptions, cost
estimates and public involvement techniques. The WWDC and the SEO organized a
Basin Advisory Group (BAG) that met on a regular basis during 1998 and submitted a
final report to the WWDC in September of 1998. The 1999 Legislature authorized the
preparation of river basin plans for the Green and Bear River Basins, which are
complete. The Bear River BAG was reconvened to assist with the planning process. A
BAG was formed in the Green River Basin for the same purpose. The 2000 Legislature
authorized the preparation of river basin plans for the Powder/Tongue and Northeast
Wyoming River Basins. BAGs are currently meeting there on a regular basis during
Plan development. Following this model, BAGs will be established in both the
Wind/Bighorn and Snake/Salt River Basin Planning Areas.
4. References. The Consultant should be familiar with the
following documents, all of which are available for review in the WWDC Office or the
Wyoming Water Plan Home Page:
Jorgensen Engineering and Land Surveying. Teton County Water Supply Master
Plan, Level 1, February 1999.
Water Development Commission, et. al. State of Wyoming Water Planning
Questionnaire Report, January 1998.
Water Development Commission, et. al. Final Report: Bear River Basin Water
Planning Advisory Group, September 1998.
Water Development Commission, et. al. 1999 Wyoming Water Planning Process
Implementation Recommendations Executive Summary, undated.
Water Development Commission, et. al. Bear River Reference Notebook, and Green
River Reference Notebook
Water Development Commission, et. al. Water Planning Newsletter. January 2001.
Water Development Commission, Bear River Basin Water Planning Process. March
Water Development Commission, Green River Basin Water Planning Process. March
Water Development Commission, Guidelines for Development of Basin Plans. March
C. PROJECT REQUIREMENTS
1. Progress Reports
The Consultant shall submit a brief monthly progress report outlining the study status,
progress, and results to date, regardless of whether or not a billing statement is
submitted, on or before the last working day of the month.
Each billing statement must include a task-by-task report and receipts for reimbursable
expenses justifying the cost items contained in the billing statement. The monthly
progress report may be used as the justification for the billing statement as long as all
cost items covered in the billing statement are addressed in the progress report.
2. Computer Models, Statement of Assumptions, Project Work File
- If the Consultant writes or uses a computer model or spreadsheet
as a part of this project, the Consultant shall submit to the WWDC for approval
all proposed model names and data formats prior to beginning work on that task.
All data shall be submitted to WWDC in written and digital form with the final
report. Digital media shall be labeled by the Consultant to provide sufficient
detail to access the information on the media. User manuals shall be submitted
by the Consultant to WWDC providing complete documentation of computer
models developed under this project. The user manuals shall also contain the
source code language and the type of computer equipment necessary to operate
the model(s). The computer models and spreadsheets (written and digital forms)
are due on the same date as the final report that contains the information
generated by the model.
- To facilitate the Commission's accurate evaluation of the Consultant's work
product, computations, conclusions and recommendations, the Consultant shall:
- Include in the final report a section describing the assumptions and
methodology used by the Consultant in generating the data and conclusions
contained in that report.
- Maintain a project work file containing the materials used in project
analysis. This file will be available for review by the Commission and should be
organized in such a way as to allow replication of the steps and procedures used
by the Consultant to reach the conclusions described in the study.
- Prepare a project notebook containing a description of the
assumptions and methodologies used in the project analysis. The notebook shall
be organized in such a way as to allow replication of the steps, calculations, and
procedures used by the Consultant to reach conclusions, described in the draft
final report. The project notebook shall be submitted with the draft final report.
3. Cost Estimates
The Consultant shall provide, as a part of project cost estimates, an estimate of:
- The cost to prepare final plans and specifications.
- The cost to acquire permits and to mitigate project impacts.
- The cost of project legal expenses.
- The cost of acquiring access and rights-of-way.
The Consultant shall use the following format and guidelines in calculating final cost estimates.
Final Cost Estimates
Preparation of Final Designs and Specifications $___________
Permitting and Mitigation $___________
Legal Fees $___________
Acquisition of Access and Rights of Way $___________
Cost of Project Components $__________
Construction Cost Subtotal #1 $__________
Engineering Costs = CCS #1 x 10% $__________
Construction Cost Subtotal #2 $__________
Contingency = CCS #2 x 15% $__________
Construction Cost Total $__________
Project Cost Total $__________
5. Final Documents
The Consultant shall use the Contract Scope of Services as the outline for draft and final documents so
that Consultant compliance with Contract provisions can be verified. IF THE FINAL DOCUMENTS
CONTAIN INFORMATION OF AN ENGINEERING NATURE, THE COVER OF THE FINAL
DOCUMENTS, ALL PLATES, AND THE EXECUTIVE SUMMARY MUST BE STAMPED AND
SIGNED BY A PROFESSIONAL ENGINEER LICENSED IN THE STATE OF WYOMING. IF THE
FINAL DOCUMENTS CONTAIN INFORMATION OF A GEOLOGIC NATURE, THE COVER OF
THE FINAL DOCUMENTS, ALL PLATES, AND THE EXECUTIVE SUMMARY MUST BE
STAMPED AND SIGNED BY A PROFESSIONAL GEOLOGIST LICENSED IN THE STATE OF
6. Final Documents - Digital Format
In addition to the paper submittal described in Section C.5 above, the Consultant shall also provide the
final documents and related materials in a digital format. This digital format shall contain the final
documents in their entirety, including all text, tables, plates, figures, etc. The deliverables under this
section shall be contained on a standard CD ROM(S). The documents shall be in Word 2000, or
compatible, format. Any plates, figures, etc. not suitable for Word 2000 shall be in AutoCAD Map
2000, ArcView 3.2, Adobe Acrobat, or compatible format. Other formats may be used if approved in
advance by the WWDC project manager. The final documents will also be provided in an "internet
ready" digital format to facilitate their distribution via the Waterplan website.
7. Anticipated Project Funding Assistance
The Consultant shall clearly identify project components eligible for WWDC funding,
both in cost estimates and in project mapping. The Consultant shall verify project
component funding eligibility with the WWDC prior to commencing any economic
analysis. Unless otherwise directed by the WWDC project manager, the Consultant
shall assume that all projects will be funded with a 50% grant and a 50% loan. The
WWDC loan portion of the project will be financed at the interest rate established by the
State Lands and Investments Board (presently 7.25% for municipal and domestic and
6% for agriculture) with a term to be specified by the WWDC project manager. If
funding is anticipated from another agency, such as the Office of State Lands and
Investments, Abandoned Mine Lands (AML), or Rural Utility Service (RUS), the
Consultant shall prepare cost estimates for system components not eligible for WWDC
assistance in a format and level of detail acceptable to the potential funding agency.
If required in the Contract Scope of Services, the Consultant shall provide the
information necessary to complete applications to RUS, the Office of State Lands and
Investments, and any other identified funding sources.
8. Project Access
The Consultant shall be responsible for obtaining access as required for project tasks.
9. Stand-By Time
The WWDC will not reimburse the Consultant for stand-by time charges for the
Consultant's supervisory personnel.
10. Well Permitting
All wells developed under this program shall list the State of Wyoming, Water
Development Commission as the permittee.
11. Verification Log
After all casing has been installed in the well, the WWDC may require that a
geophysical log be performed on the well to verify casing placement. A copy of this log
shall be included in the final report.
12. Units of Measurement
All units of measurement used in the water planning process shall be English.
D. SCOPE OF SERVICES
Task 1. Meetings
The Consultant shall attend Basin Advisory Group (BAG) meetings, which will be held every
other month for the duration of the contract. For cost estimating purposes the
Consultant shall assume twelve meetings with the BAG, three hours in length, in the basin.
WWDC will arrange meeting places, provide public notification, prepare agendas, and provide
a facilitator for the regular BAG meetings. The Consultant shall be prepared to give a
presentation on current work progress at each meeting and to respond to comments from those
in attendance. The Consultant shall prepare the meeting record for each meeting in a format
determined by WWDC, and deliver same, in both digital and written formats, to WWDC within
7 days of the meeting. The meeting record should include any handouts distributed at the
meeting, as well as a copy of any presentations.
Project meetings shall be conducted as necessary for the coordination of project activities and
for informing the WWDC of project progress. Due to the number of agencies, entities, and
individuals with a stake in the outcome, the Consultant shall be in regular contact with the
WWDC Water Plan Project Manager, and will coordinate on a regular basis with the
Consultant under contract with WWDC to prepare the Snake/Salt River Basin Plan. This
coordination is necessary to promote consistency in the basin planning process and
compatibility of planning products. For cost estimating purposes the Consultant shall assume
eighteen project meetings will be held in Cheyenne.
Task 2. Basin Water Use Profile
The Consultant shall inventory current consumptive and non-consumptive surface water and
groundwater use within the basin of interest. Water use will be divided into the following
Water Use from Storage
The Consultant shall identify and document, to the extent feasible, all previous water use,
availability, modeling, and conservation studies and, where applicable, incorporate those results
into this task.
Concurrent with developing the Basin Water Use Profile, the Consultant shall collect
information regarding both actual and perceived current water problems within the basin. The
Consultant shall use the Basin Advisory Group (BAG) as a resource in identifying water
concerns. The Consultant shall prepare a technical memorandum outlining water-related
concerns within the basin, including location and approximate magnitude of current water
shortages and water quality issues. Water quality issues should include sediment, total
dissolved solids and individual constituents, and point source discharges.
At a minimum, the Consultant should utilize the resources of the Water Resources Data System
in compiling existing reports and information under this task.
Base Topographic Data
The Consultant shall develop a 1:24,000 scale digital map based on USGS Quadrangle
Mapping for the basin. These base maps should include hydrography, roads, towns, and other
physical features. The individual GIS layers in base maps shall be used to provide context,
when appropriate, to other planning product layers as well as a source for general
Scale, Format, and Accuracy of GIS Data
The Consultant shall use and prepare the appropriate scale GIS data as specified in the Scope of
Services and under the direction of the project manager. The Consultant shall only represent
map scale as intended by the creators of any specific GIS coverage. (For example, 1:100,000
scale GIS data should be noted as such when represented in association with 1:24,000 scale
data.) GIS layers created as part of this scope shall be at a 1:24,000 scale. Basin planning
products compiled from existing GIS data sources forthis scope shall use the largest scale data
available. Refer to WWDC, Guidelines for Development of Basin Plans.
The Consultant should identify, record and use the most current data available to produce
planning products, and shall adhere to USGS National Mapping Accuracy Standards when
developing GIS planning products. The Consultant shall record and provide metadata on all
GIS products, including AutoCAD files with geo-referenced information. All metadata will be
Federal Geographic Data Committee compliant. All GIS deliverables will be provided as Arc-
Info export files and ArcView Shape files, and will be in Geographic, NAD27 DD format. In
general, all data generated during the planning process shall be of sufficient detail,
documentation and accuracy to meet litigation standards. Data standards may be defined in
greater specificity in the Consultant contract.
2A. Agricultural Use
The Consultant shall estimate the agricultural use within the basin by determining
current irrigated acreage, estimating crop types, and estimating crop consumptive use.
In addition, the Consultant shall obtain diversion records applicable to the selected
period of record, and prepare descriptions of large irrigation operations.
1. Determine Irrigated Acreage
The Consultant shall acquire or prepare irrigated lands mapping for the study
area. Irrigated lands mapping has been completed in the past few years for the
areas shown on the attached maps. This existing work is available from
WWDC, and should be utilized in this effort. The Consultant shall prepare
mapping for those irrigated lands in the study area where current mapping is
not available. This work should be based on current imagery. If suitable
imagery is not available it shall be acquired as part of this project. These
coverages shall be imposed on a 1:24,000 scale digital USGS Quadrangle Map
based in ArcInfo. These coverages shall be consistent with the Wyoming
Geographic Information Advisory Council (WGIAC) GIS Hardware and
Software Standards, and mapping completed for the Green, Bear,
Powder/Tongue, and Northeast Wyoming River Basins. This base mapping
shall include topography, hydrography, roads, towns, and other physical
features in the basin.
The State Engineer's Office Water Division Superintendent will assist in field checking to
verify actual usage. The Consultant shall incorporate the Division Superintendent's comments
and corrections into the final irrigated acreage mapping, and actual acreage under irrigation will
be determined. The Division Superintendent will also be questioned regarding lands where
consumptive use requirements are generally not satisfied by available water supplies.
2. Estimate Crop Types
Water requirements vary by crop type; therefore, it is necessary to estimate the types of crops
under irrigation. The Consultant shall determine cropping patterns using Wyoming
Agricultural Statistics and National Resource Conservation Service (NRCS) data for irrigated
lands published yearly by county. The local water commissioner and irrigation district officials
will be contacted to review the resultant crop types, to provide additional detailed information
on cropping patterns, and to provide input on yearly variance in crop types.
3. Estimate Crop Consumptive Use
Based on the irrigated acres of each crop type, water requirements can be estimated. The
Consultant shall use consumptive use values presented in WWRC Publication #92-06,
"Consumptive Use and Consumptive Irrigation Requirements in Wyoming", or more recent
documents as approved by the WWDC. In addition to average monthly consumptive use, dry
year and wet year monthly consumptive use values will be determined. Dry and wet year crop
consumptive use will be determined from the maximum and minimum values reported in
WWRC publication #92-06.
Water-short systems may not be able to satisfy consumptive use requirements during average or
dry years. Therefore, a realistic value of actual water use, or supply-limited consumptive use,
must be estimated. Based on previous water use studies, and information from the local water
commissioner, the Consultant shall estimate the water supply-limited consumptive use for
water-short systems. Estimated supply-limited consumptive use will replace calculated
consumptive use for the associated acres.
4. Determine Source of Supply
The Consultant shall review the irrigated lands mapping and determine the source of supply,
including groundwater, surface water, and storage. Defining the agricultural use in a basin does
not require that specific lands irrigated be associated with their individual water rights.
Therefore, associating each water right with its respective irrigated acreage is not included in
this scope. The SEO maintains a groundwater database containing up-to-date groundwater
permits that is considered an accurate representation of current well locations and uses. The
Consultant shall query the groundwater database for groundwater permits issued for agricultural
use, and utilize other records of the SEO as appropriate. Monitor well permits, enlargement
permits, and canceled or abandoned permits should be excluded. The Consultant shall catalog
all active agricultural wells with permitted production rates equal to or greater than 50 gallons
per minute. The locations of agricultural wells will be determined from the SEO database and
incorporated into a GIS layer at 1:24,000 scale. Lands irrigated under groundwater permits will
be identified. The Consultant shall assume that consumptive use requirements not met by
adjudicated wells are met by surface water sources, including storage.
The Consultant shall perform water right attribution for all water rights within the basin
excluding only stock permits. This will include the following tasks:
- Obtain or prepare maps that identify polygons of irrigated lands.
- Compare these polygons to the records of the State Engineers Office for both
surface and groundwater.
- Abstract water right information (permit number, priority, amount, use, type,
etc.) and assign the polygon an attribute number.
- Associate polygon attribute numbers with water right information and develop
- Submit draft mapping to the appropriate State Engineer's Office personnel for
review and comment.
The Consultant shall compile, as appropriate for the selected period of record, all diversion
records for diversions with headgate capacity equal to or greater than 10 cfs from the Board of
Control Hydrographer's Annual Reports, from irrigation district records, and from WRDS
Hydrographer/Commissioner reports. These diversion records shall be associated with the
appropriate irrigated acreage. The Consultant shall prepare operating information
memorandums for ditches with capacity equal to or greater than 10 cfs, and for each irrigation
district. Each memorandum should include a brief history, a general description of the system,
water rights and structure operations, additional supplies from storage, general location and
distribution of return flows and how these were determined, and a physical description. These
memorandums should give enough detail to assist in any level of flow modeling, from simple
water budgets to detailed computer simulation models. The diversion record information
should be tabulated by recording interval, and should be presented in an Excel spreadsheet
Data on agricultural use will be compiled and presented in tabular, graphical, and spatial forms.
Examples of data to be presented include:
- Irrigated lands by major tributary basin.
- A summary of crop distribution.
- Monthly agricultural water use (surface and groundwater) for average, wet, and
- Location and permit data for agricultural wells.
2B. Municipal and Domestic Use
During the summer of 1999, the WWDC conducted a survey of known municipal and non-
municipal community public water systems in Wyoming. The Consultant shall use the State of
Wyoming 2000 Water System Survey Report, online at http://waterplan.state.wy.us , to determine the municipal
and rural domestic water supplies/uses within each basin. Information regarding the average
and peak day use, as well as the surface source of water and/or the number of supply wells, is
published in this document.
The Consultant shall identify wells permitted for municipal use by the SEO, and place the
information in a GIS data layer / spatial database. Monitor well permits and canceled or
abandoned permits should be excluded. The Consultant shall catalog all active wells with
permitted production rates equal to or greater than 50 gallons per minute. The Consultant shall
use the WWDC Water System Survey to determine the average monthly diversion and/or
pumping, additional supplies from reservoirs, the estimated consumptive use, the river location
of treated return flows, and variance in average use during dry and wet years for each
municipality. The Consultant may complete this data by direct contact with individual system
administrators if necessary. If these data are unavailable, the average day use from the Water
System Survey will be used and the consumptive use will be estimated to be forty-five percent
(45%). This value is considered acceptable.
The Consultant shall identify wells permitted for domestic use. These wells shall be aggregated
into groups of appropriate size and the information placed on a GIS data layer at a
Data on municipal and domestic use will be compiled and presented in tabular, graphical, and
spatial forms. Examples of data to be presented include:
- A breakdown of groundwater and surface water supplied for public water
- A listino of average monthly consumptive municipal water use.
- A summary of permitted domestic use.
- Locations of municipal water use within the basin.
- Locations and permit data for municipal wells and aggregated domestic
Determining surface water rights for municipalities is not necessary for defining the municipal
water use within a basin, therefore it is not included in this scope.
2C. Industrial Use
In many areas of Wyoming industrial water use is a significant component of the
overall basin water use. The Consultant shall identify industrial users not supplied
through municipal systems through discussions with local water commissioners, county
assessors, and others. Wells permitted for industrial and miscellaneous use (non-municipal and
non-public water supply) will be identified from the SEO records and shown on a GIS data
layer. Monitor well permits, enlargement permits, and canceled or abandoned permits should
be excluded. The Consultant shall catalog all active wells with permitted production rates
equal to or greater than 50 gallons per minute for all industrial uses. The Consultant shall
survey identified users to determine their average monthly diversion and/or pumping, and their
resulting consumptive use. If these data are unavailable, the maximum permitted production
rate will be assumed for wells, and the consumptive use will be estimated based on the average
consumptive use for the type of industry.
Data on industrial and miscellaneous use will be compiled and presented in tabular, graphical,
and spatial forms. Example of data to be presented include:
- Groundwater and surface water produced for industrial use.
- Average monthly industrial water production/use.
- Locations of industrial water production/use within the basin.
- Locations and permit data for industrial wells.
Determining and cataloging surface water rights for industrial use is not necessary for defining
the industrial water use within a basin, therefore it is not included in this task.
2D. Recreational Use
The Consultant shall compile readily available data and mapping on public
campgrounds, marinas, state and national parks, and historic areas and monuments in the basin,
as an indicator of water-related recreational activity. The Consultant shall hold discussions
with the Wyoming Business Council, the Wyoming Department of State Parks, the Wyoming
Game and Fish Department, and others regarding economic information on recreation. The
Consultant shall prepare a memorandum that describes qualitatively the water-related
recreational activities within the basin, and brackets the optimum reservoir levels and
streamflows that promote maximum use. Existing GIS mapping showing stream classification
and other recreational information will be identified and referenced, and included as appropriate
in the basin plan.
2E. Environmental Use
Environmental water use, including minimum reservoir pools and releases, and instream bypass
requirements to enhance fisheries and wildlife habitat, is important in defining the overall water
use within a basin. The Consultant shall compile existing minimum reservoir releases and
instream bypasses, and show their location on a GIS map layer. Existing GIS mapping showing
wetlands, big game habitat, and other environmental information will be identified and
referenced, and included in the basin plans. The Consultant shall survey local environmental
interests for input. The Consultant shall prepare a memorandum that describes qualitatively the
water-related environmental uses and benefits within the basin and brackets the optimum
streamflows and/or reservoir levels for these benefits.
2F. Water Use from Storage
Storage of supplemental water for municipal, industrial, and late-season agricultural use is often
an important component of basin water use in Wyoming. The Consultant shall identify all
reservoirs permitted for other than stock uses from the State Engineer's Office records.
Information to be obtained for each reservoir, as applicable to the selected period of record,
includes: permitted storage rights, historical end-of-month reservoir contents, area-capacity
tables, evaporation rates, spillway and outlet capacity, project water right owners, average
monthly release rates, and operational criteria including flood forecasting and hydropower
generation. Diversions served by the reservoir will be identified and shown on a GIS layer. An
operation memorandum will be prepared for each reservoir in sufficient detail for use in flow
Data on reservoir storage will be compiled and presented in tabular form. Examples of data to
be presented include:
- Reservoir capacities and pertinent information (use, permit Nos., priority date,
etc.) including location map.
- Average monthly storage for reservoirs.
- Estimated average monthly evaporation for reservoirs.
Task 2. Deliverables
Tabular, Graphical, Spatial Data
- Irrigated acreage by major sub-basin, and entire basin
- Crop distribution
- Average, wet, and dry year monthly agricultural use
- All agricultural diversion records
- Agricultural well information
- Reservoir locations and tabulation of reservoirs
- Average monthly municipal water use, including groundwater
- Average monthly industrial water use, including groundwater
- Inventory of all irrigated lands in the basin, by major sub-basin, with
associated water right information for both surface and
- Bibliography of previous water use studies
- Current water shortages and other concerns
- Diversion operations
- Reservoir operations
- Agricultural water use
- Municipal water use
- Industrial water use
- Recreational water use
- Environmental water use
Task 3. Available Surface Water and Groundwater
The Consultant shall develop spreadsheet modeling tools to determine streamflow in the basin
during average, wet, and dry years, under current operating conditions. This tool will be used to
verify the water use determined in Task 2, to determine additional available flow for future use
including the constraints of compacts and decrees, and to assess the impacts of future water use
opportunities. The modeling shall be documented within the spreadsheet through visible
equations, links, and text descriptions of assumptions and data sources. The Consultant shall
identify available groundwater supplies.
3A. Surface Water Data Collection and Study Period
Diversion records, reservoir operations and physical parameters, return flow
information, and consumptive use estimates, gathered or determined in Task 2, will be
required. Additional data to be collected include streamflow records, average monthly
precipitation, and water sales. A base map will be prepared showing basin hydrography
on a GIS layer at 1:24,000 scale. This mapping shall include basin and sub-basin
boundaries, stream networks, and major (>200 acre-feet) reservoirs and lakes.
Based on available data the Consultant will select a study period for use in the model to
represent average, wet, and dry years. It is important that the period of record used in the model
reflects the range of conditions experienced in the basin over the long term. The study period
should ideally have a prolonged period of drought, a period of high runoff years, and periods
reflecting average conditions. The Consultant shall use the entire selected period of record to
determine the average year monthly streamflows. Annual total streamflow values will be
ranked, with the years failing at or below the 20th percentile used to determine dry year
monthly streamflows. The years falling at or above the 80th percentile will be used to
determine wet year monthly streamflows. The average monthly flows for each period
representing average, wet, and dry conditions will be determined from the arithmetic mean of
the representative data. Coordination with the Northeast, Powder/Tongue, and Wind/Bighorn
River Basin Plan Consultants will be performed throughout this process to provide consistency
in spreadsheet model assumptions and output format.
3B. Surface Water Data Synthesis and Spreadsheet Model
When performing mean monthly analyses, gaps in available data can often be ignored by simply
not using any data for these months or years. If necessary, the Consultant will extend and fill
gaps in the available data using appropriate, accepted hydrologic techniques, as approved by
WWDC. Data to be synthesized include streamflow, reservoir end-of-month contents, and
diversion records. The Consultant shall determine mean monthly flows and reservoir storage
values by calculating the arithmetic mean of the available data for each month. Average, dry
and, wet year monthly water use determined in Task 2 will be used. If diversion records were
obtained, diversions and return flows will be accounted for, otherwise, consumptive use
estimates will be used.
The Consultant shall review the locations of water use and storage identified in Task 2F. Each
of these locations will be represented as a node and the stream reaches between each node will
be modeled. Typically, only tributaries with diversions are included. Other tributaries may be
represented as a node to account for contributing streamflow. In addition, the Consultant shall
represent streamgage locations as nodes. If necessary, the linked node representation will be
modified to better suit the available data. The Consultant shall provide a schematic of the
linked node representation.
The Consultant shall develop virgin flows at each node selected for inclusion in the analysis. If
no major single or aggregate diversions or storage facilities exist above a node, historical flows
represent virgin flows and no adjustments will be required. Small diversions not identified
during Task 2 will be left in the gage - they will not be added back in during virgin flow
development nor subtracted out during model development. If identified diversions are made
upstream of a node, the flows will be adjusted to a virgin condition by adding back diversions,
and subtracting out flows that return that month above the node. In addition, the effects of
upstream storage facilities will be added or subtracted. If tributaries with substantial diversions
are not gaged, factors will be developed to distribute virgin flows seen at downstream gages
based on drainage area and precipitation. Historical gains and losses due to groundwater
interaction and stream surface evaporation will be estimated during the virgin flow
determination process, along with other ungaged inflows, as the difference between gaged
flows when all known storage and diversion effects are accounted for.
For the agricultural, municipal and industrial diversion records obtained in Task 2, return flows
will be calculated as diversion less consumptive use. Industrial and municipal return flows will
be assumed to return to the river during the month of diversion, unless otherwise determined in
Task 2. The Consultant shall estimate agricultural return flow timing and location using data
derived from existing studies, if available. Based on the information gathered in Task 2,
generalized return flow patterns and timing will be estimated and applied as appropriate.
If diversion records are not available, the consumptive use determined in Task 2 will be used
directly rather than estimating both diversions and return flows.
The Consultant shall develop three spreadsheets to simulate river flows within the basin for
average, wet, and dry year conditions. Average streamflows will be calculated at each node
beginning with the virgin flow at the headwater reaches. Diversions will be subtracted from the
nodes and return flows added back in at the nodes, or, if no diversion records exist, depletions
may simply be subtracted. The simple addition and subtraction will proceed sequentially
downstream until the basin mouth is reached. The Consultant will take compact or decree
restrictions into consideration in model development, and will coordinate with WWDC to
establish the nature and parameters associated with these restrictions. As a starting point, the
Consultant shall utilize the spreadsheet model developed by previous River Basin Consultants
to ensure consistency.
3C. Surface Water Model Calibration
Each model will be calibrated by comparing the average simulated flows to average measured
flows at key streamflow gages. Likewise, the simulated end-of-month reservoir contents will
be compared to average measured end-of-month reservoir contents, where available. If
necessary, the Consultant shall review and adjust any assumptions made during Task 2 and
Task 3 until modeled and historical streamflows and reservoir contents match reasonably well.
The Consultant shall prepare a memorandum that outlines the modeling process including data
extension methodologies, modeling assumptions, and calibration results.
3D. Available Surface Water Determination
The Consultant shall execute the spreadsheet model to determine the available flows in the
basin for average, wet, and dry year conditions. The Consultant shall prepare a memorandum
that describes the results of the three model executions and outlines available flows in tributary
and main stem reaches.
3E. Available Groundwater Determination
The Consultant shall characterize the aquifers in the study area based on existing
information. The Consultant shall identify and document previous groundwater studies
and planning documents and, if applicable, incorporate that information into this task.
The Consultant shall prepare a groundwater model(s) for appropriate areas and aquifers
in the study area if necessary to accurately understand the groundwater resources and
development potential in the basin. The Consultant shall prepare a memorandum
discussing the potential for additional aquifer storage and development and the potential
effects, if any, that development might have on the groundwater and surface water
Task 3. Deliverables
Tabular, Graphic, Spatial Data
- Basin hydrography
- Average monthly precipitation
- Schematic of linked-node representation
- Spreadsheet modeling tools
- Aquifer locations
- Aquifer storage and yield potential
- Bibliography of previous groundwater studies
- Modeling process
- Model execution and available flows
- Aquifer storage and yield potential
Task 4. Demand Projections
4A. Review Socioeconomic, Economic, Demographic and
other data sources
- Gather current and recent historical economic and demographic data for the
- Where relevant for subsequent analysis and modeling -- gather data for the State
of Wyoming and the U.S. as a whole.
- Examine and evaluate projections of economic and demographic change for the
study area, the relevant counties, the State of Wyoming as a whole and, as
relevant, for the U.S.
- In particular, examine both the Wyoming Population Forecasts and the
Wyoming Economic Forecast Model, available through the State Data Center.
- Gather and evaluate available projections from the Wyoming Business Council,
and other sources.
- Develop charts and tables summarizing current economic and demographic
conditions in the study area, trends in key economic and demographic measures and key
4B. Identify Planning Scenarios
- Develop preliminary recommendations for baseline, moderate growth, and high growth
- Review recommendations for consistency with the Northeast, Powder/Tongue, and
Wind/Bighorn River Basin Plan economic consultants and resolve or justify differences.
- Recommend three alternative planning scenarios (baseline, moderate and high growth)
for approval by the WWDC.
4C. Define Methodology
- Define the methodology for developing water demand projections for the basin.
- Examine and evaluate the appropriateness of alternative economic modeling tools (e.g.
input-output models and econometric models).
- Among the methodological issues to be determined in this subtask are:
- Basis for projected changes in basic sector activity and employment;
- Technique for linking basic employment to local service employment;
- Feasibility of cohort component demographic modeling versus simplified
- Key assumptions (commuting patterns into and out of the basin, labor force
participation rates, etc.);
- Develop preliminary recommendations regarding methodology and assumptions for
water demand projections.
- Review recommendations for consistency with the Northeast, Powder/Tongue, and
Wind/Bighorn River Basin Plan economic consultants and resolve or justify differences.
- Make recommendations regarding methodology and key assumptions to the WWDC,
along with a description of the basis for those recommendations.
4D. Construct and Calibrate Economic and Demographic
- Construct and calibrate economic and demographic forecasting model(s).
- Conduct interviews with local sources as needed to better understand key industries and
other economic and demographic aspects of the basin.
- Use the model to produce projections of economic activity and population under each of
the three planning scenarios. The projections will incorporate a thirty-year horizon.
- Review the economic and demographic projections prior to developing related
projections of water demand.
4E. Project Water Demands
- Develop water demand projections under each of the three planning scenarios
- Incorporate water demand coefficients appropriate to each water use sector.
- Incorporate water requirements for recreation and environmental needs.
- Document the water demand projections in a task memorandum.
- Review the water demand projections with the Basin Advisory Group.
4F. Consistency Reviews with Wind/Bighorn River Basin Team
- Prepare for and participate in two Cheyenne meetings with the Wind/Bighorn Consultant to
compare and coordinate methodologies, models, and data developed during the course
of the study.
- Offer and consider suggestions on how to keep the two basin studies consistent with
each other, and with the Northeast, Powder/Tongue, Green, and Bear River Basin Plans.
Task 4. Deliverables
Tabular, Graphic, Spatial Data
- Planning scenario recommendations
- Forecast methodology recommendation
- Forecasted agricultural, municipal, industrial, recreational, and
Task 5. Future Water Use Opportunities
The Consultant shall use the current shortages and needs identified in Task 2, water availability
identified in Task 3, projected future demands identified in the Task 4, and information
generated through the Basin Advisory Group (BAG) meetings as a basis for this task. Both
structural and non-structural potential future water use opportunities will be identified to meet
current shortages and needs, as well as the Baseline, Moderate, and High levels of projected
demand. Both surface water and groundwater sources will be
considered. Future water use opportunities will be identified to satisfy projected
agricultural, municipal, industrial, recreational, and environmental demands.
5A. Describe Issues Affecting Future Water Use
The Consultant shall identify issues that may potentially restrict future water use
opportunities in the basin. The issues include, but are not limited to, water quality
issues, compact requirements, federal legislation such as the Endangered Species Act,
the Clean Water Act, and the Safe Drinking Water Act, etc. The Consultant shall
prepare memorandums that describe potential limitations to future water use due to
these, and other issues.
5B. Define Water Use Components Screening Criteria
The Consultant shall develop evaluation criteria and methods for comparing and ranking
alternative structural and non-structural components according to the following factors:
water availability, technical, economic, environmental, legal and institutional, public
acceptance, water quality, and ability to satisfy multiple demands. Defining the
screening criteria prior to developing a long-list helps assure that the criteria are not
biased towards any particular future water use opportunity. The criteria will be
submitted to the BAG for review and to the WWDC for approval.
5C. Develop Long-list of Future Water Use
The Consultant shall compile a list of potential structural and non-structural
opportunities to meet current and projected demands. The long-list will include new
and previously proposed projects in the basin, common solutions to water shortages
applicable to the basin, opportunities identified by the BAG, and others. Structural
components may include, but are not limited to storage reservoirs, conveyance system
upgrades, water distribution system enhancements, groundwater development, aquifer
storage and recovery opportunities, in-basin water transfer components, and trans-basin
diversion components. Non-structural components may include, but are not limited to
local and basin-wide conservation and management, revised reservoir operations,
municipal conservation, improved farm efficiencies, water right transfers and
exchanges, water banking, and conjunctive use options.
5D. Develop Short-list of Future Water Use
The Consultant shall develop a short-list of future water use opportunities for review by
the BAG and WWDC. The Consultant will use the results of the flow modeling
spreadsheets to determine mainstem and tributary reaches with flow available for future
use. Proposed opportunities that do not, in whole or in part, satisfy existing shortages or
projected demands will be eliminated. Information such as land ownership, wetlands,
threatened and endangered species, impaired stream segments, water quality issues,
floodplain mapping, and cultural resources will be used to identify fatal flaws likely to
restrict permitting of structural projects. Aquifer storage, groundwater quality, and yield
potential will be used to identify fatal flaws associated with groundwater development
and conjunctive use options. Some of the information used to identify fatal flaws may
be available in the Groundwater Vulnerability modeling done by the Department of
Environmental Quality, and other spatial databases, and should be used to explain the
results of this task.
5E. Apply Screening Criteria to Rank Short-list of Future
Water Use Opportunities
The screening criteria approved by WWDC will be used to rank the short-list of
future water use opportunities. The Consultant will determine the ranking using all
screening factors. The Consultant will present this work to the BAG at one of their
regular meetings, and the rankings and comments will be submitted to the WWDC for
5F. Water Quality Issues
The Consultant shall identify basin-wide opportunities to enhance or protect water
quality. The Consultant shall identify and describe on-going watershed management
planning by other entities, and define opportunities for cooperation and coordination
among these efforts. State and Federal agencies and other appropriate entities will be
contacted to identify areas within the basin where water quality issues are being
investigated, including the Department of Environmental Quality, the State Engineer's
Office, the Game and Fish Department, the Wyoming Association of Conservation
Districts, the Bureau of Land Management, the Natural Resources Conservation
Service, the U.S. Geological Survey, and the U.S. Environmental Protection Agency.
Monitoring locations and areas of concern identified by these sources will be described,
and shown on a GIS layer.
Task 5. Deliverables
Tabular, Graphic, Spatial Data
- Collection of existing GIS layers (cultural resources, endangered
species, critical habitat, etc.) to identify fatal flaws
- Mapping showing proposed future water use opportunity
- Potential limitations to future water use
- Screening criteria
- Long-list of future water use opportunities
- Short-list of future water use opportunities
- Opportunities to enhance or protect water quality and coordinate efforts
Task 6. Basin Advisory Group Discretionary Task
This task holds 15% of the total contract amount in reserve to address issues identified by the
Basin Advisory Group and WWDC. The Consultant shall not proceed with any work under
this task until approved in writing by WWDC.
Task 7. Basin Planning Report
On or before November 1, 2002, the Consultant shall submit to WWDC:
- Fifteen (15) copies of the draft report presenting the results of this study;
- One (1) project notebook as described in subsection C.2.b.;
- One (1) copy of all Technical Memorandums;
- Digital copies of the above;
On or before December 15, 2002, after receipt and incorporation of WWDC review comments,
the Consultant shall submit to WWDC:
- One hundred (100) stamped and signed copies of the final report;
- One (1) stamped and signed unbound reproducible original of the final report;
- Two hundred (200) stamped and signed copies of the Executive Summary, to be
no more than ten (10) pages in length;
- One (1) stamped and signed unbound reproducible original of the executive
- Fifty (50) stamped and signed copies of all Technical Memorandums;
- One (1) stamped and signed unbound reproducible original of all Technical
- Ten (10) digital copies of the final report, all related text files, database files, and
GIS coverages. The Consultant will also provide ten(10) digital copies
of the documents described above in an "internet ready" format. This
information will comply with the formatand standards set by WRDS for water
The Consultant may be asked to participate in public meetings, legislative hearings or WWDC
meetings to present findings. The Consultant should budget for two (2) meetings after the
submittal of the draft report, one in Cheyenne and one in the basin of interest.