South Platte and Metro Basin Water Entities

This story highlights the various types of water entities in the South Platte and Metro basins, such as municipalities, municipal water providers, agriculture, environmental, recreational and industrial entities.

The purpose of this story is to provide general context for the number, location and extent of such entities in the basin, provide links to useful datasets and highlight important water resources issues.

Background on Colorado water law and other topics is included to provide context and references for Colorado water resources.

See the Instructions page for how to view this story. Created by the Open Water Foundation.

Water Resources Concepts

Water comes from one of two sources: surface water or groundwater. Streams and their associated watersheds, lakes and reservoirs comprise the surface water network. Groundwater exists in aquifers. Aquifers consist of permeable rock or materials such as gravel, sand or silt that can contain or transmit water. Groundwater often exists in shallow alluvial aquifers that return the water to streams underground, but this can take months or years. Some groundwater can filter into deeper aquifers and remain there for thousands of years. Groundwater is available for use via wells or springs.

The predominant water source for Coloradans is surface water from snowmelt, rain and surface water reservoirs that release stored water.

The following is a concise summary of the surface water network of the South Platte Basin (Citizen's Guide to Where Your Water Comes From, p.20):

"The headwaters of the South Platte River are formed by the combination of several smaller rivers--the north, middle and south forks...The north fork of the river originates in the peaks around Mt. Evans while the south fork originates in the South Park area. In South Park, the south fork is impounded by multiple reservoirs: Antero, Spinney Mountain and Eleven Mile Canyon. It drops many feet in elevation before exiting the mountains and flowing into Cheesman Reservoir. The South Platte then makes its way through Denver to Greeley, where it travels northeast to its confluence with the North Platte River at North Platte, Nebraska...Many substantial tributaries feed the South Platte. North to south, these include the Cache la Poudre, Big Thompson, St. Vrain, Boulder Creek, Clear Creek, Tarryall Creek, Cherry Creek, Sand Creek and others. In the lower South Platte, many off-channel reservoirs store water diverted from the river so that it can be used at a later time. These include: Barr Lake, Riverside, Empire, Sterling, and Julesburg reservoirs."

Colorado Water Rights Concepts

The following information is derived from the Citizen's Guide to Colorado Water Law.

The Colorado Doctrine is a set of laws regarding water use and land ownership, adopted by Coloradans in the 1860s. One of its essential principles is that water is a public resource and can be used for beneficial use by public agencies, private persons and entities. Beneficial uses include uses for municipal water supply, agriculture, industry and recreation, among others.

A legal framework called the prior appropriation doctrine regulates the use of surface water and tributary groundwater that is connected to streams. This doctrine is also referred to by the phrase "first in time, first in right". This means that in times of short water supply, court-decreed water rights holders who obtained their rights earlier (senior rights) can use water before decreed rights with later dates (junior rights) may use any remaining water. The water user must have a definite plan to divert, store or otherwise capture, possess and control water, and must specify the place of diversion or storage, amount of water, type of use and place of use. Water is administered by the Colorado Division of Water Resources.

Water rights holders are typically organizations such as municipal utilities, ditch companies, natural resource organizations or industries, although individuals can also own water rights. The costs for water rights are passed on to water users. For example, utility customers or farmers in a ditch company pay for the delivery of water and those payments cover the costs of acquiring water and the infrastructure to deliver the water.

Another important beneficial use of water in Colorado is to keep the water in the stream. The Colorado Water Conservation Board is legally permitted under state law to make instream flow appropriations. These are meant to assist in preserving the natural environment to a reasonable degree by ensuring and enhancing minimum flows. However, these instream flow rights typically are junior rights.

Water Use Concepts

Many entities compete for Colorado's water resources for various uses. These entities need water at different times of the year. Streams have peak runoff flows from snow melt in May and June; to capture this water, storage water rights are obtained that allow for the storage of water in reservoirs until the water is needed. For example, agricultural demand for water is typically only from May to October. Municipal water demand is fairly constant throughout the year for indoor use but greatly increases for outdoor use in the summer months to water landscaping. Environmental and recreational flow requirements vary by species and recreational activity. The graphic at right (from Headwaters Magazine, The Energy Issue, p.12) shows statewide water withdrawals.

Of primary interest is the consumptive use of water. Consumptive use is the amount of water that is permanently withdrawn from its source because it has evaporated, has been transpired by plants, incorporated into crops or it is directly consumed by people, livestock and industries. Water that is diverted for municipal, industrial or agricultural purposes that is not consumed returns to rivers and/or aquifers by surface flows or underground flows. These surface and underground flows are collectively called return flows and can be used by downstream water users. Water that is diverted from other basins, such as the Colorado River, can be 100% consumed. Specific requirements may be in place for certain transbasin diversions. For example, Colorado-Big Thompson (C-BT) transbasin diversions are single-use; this ensures that entities in the Northern Water (the administrator of C-BT water) service area benefit from return flows.

Statewide, 89% of consumed water goes to agriculture, 7% goes to municipalities and about 4% goes to large industries (Citizen's Guide to Colorado Water Conservation, p.3). Note that this is consumed water, not total water withdrawals as shown in the graphic at right. Withdrawals are generally equivalent to diversions.

However, while agriculture consumes the most water, the U.S. Geological Survey has estimated that approximately only 37% of the water diverted statewide for agriculture is actually consumed (Citizen's Guide to Where Your Water Comes From, p.12). Irrigation return flows are often reused multiple times. Because of this repeated reuse of water, the annual diversions in a river basin can be multiple times the natural water supply.

A water right that was originally decreed for one use, such as agriculture, can be transferred to other uses, such as municipal supply. In this case, the consumptive portion of a water right can be transferred and historical return flow patterns must generally be maintained. Some storage is typically required to assure timing. Transbasin diversions that are returned from wastewater treatment plants are also an important source of water to meet requirements.

Pumping of alluvial groundwater for urban and agricultural uses can remove water from the river and leave senior surface water users with less water than they had previously. In these situations, engineering plans called "augmentation plans" are required to ensure that water extracted from groundwater wells does not unfairly take water from surface water users or senior well users. These plans must be approved in a water court. Permits for new wells are frequently denied unless they also contain an augmentation plan (Citizen's Guide to Where Your Water Comes From, p.17).


There are 117 municipalities in the South Platte and Metro Basin. Collectively, the South Platte and Metro Basin is the most populous basin in Colorado. Approximately 85% of Colorado's population resides in the Front Range. By 2050, the Basin's population may nearly double from approximately 3.5 million people to 6 million people (CWP, p.3-12).

The 10 largest cities in the Basin, based on 2016 population data, from largest to smallest, are: Denver, Aurora, Fort Collins, Lakewood, Thornton, Arvada, Westminster, Centennial, Boulder and Greeley (see next page for population numbers). Each contains over 100,000 people. Except for Colorado Springs and Pueblo, these are also the largest cities in the State (Colorado Springs is the second largest city; Pueblo is the ninth largest).

In this map, municipalities are color-coded by 2016 population and sized by the percent change in population from 2006 to 2016. The greatest percentage changes in population since 2006 are those municipalities in the northern Front Range and include Firestone, Frederick, Johnstown, Mead, Severance, Timnath, Wellington and Windsor. These municipalities may have undeveloped water supplies (own water rights but have not used them) or may seek new supplies from various sources.

Municipal Population Data

Historical population trends and projections are important to understand because more people generally translates to overall higher water demand. (Water use efficiency is discussed in a later section).

This map shows municipal population from 1980 to 2016. Click the "Play" button on the lower-left side of the map to automatically move through the years. Municipalities are color-coded by population and sized by percent change since 1980.

The table below shows the 2016 population (the most recent year of available data) for each municipality in the Basin, as well as the percent of the total state population (5,538,180) and the cumulative percent of the state population. Note that the cumulative percent does not total 85% as stated in the previous page.

Source: Department of Local Affairs State Demography Office, County and Municipal Population Time Series 1980-2016.

Population Projections to 2050

Population growth is the single largest driver of the need for additional water supplies in the South Platte River Basin (BIP, p.1-17). Water providers and agencies typically plan for water demand and supply using a long lead time because of long timelines for project implementation.

The Department of Local Affairs (DOLA)'s State Demography Office provides population projections to the year 2050 for each of Colorado's counties. This choropleth map shows county populations for the years 2018 to 2050. Click the "Play" button on the lower-left side of the map to automatically move through the years. (Source: Department of Local Affairs State Demography Office, Population Forecasts - years (2000-2050), 1 year increments.)

As part of the Colorado Water Plan, five planning scenarios were developed that represent how the State's alternative water futures may look in 2050. The scenarios are based on drivers such as population, land use, climate predictions, social values, etc., and are intended to bracket possible growth scenarios. These scenarios are described briefly below in terms of how population may affect water supplies (Colorado Water Plan, p.6-7).

  • Hot Growth - the economy is thriving, which fuels development. A warming climate draws people to relatively cool Colorado and communities struggle to provide needed services. Families seek low-density housing and rural mountain living, resulting in rapid development of open lands.
  • Adaptive Innovation - again, the economy is thriving, and the warm climate draws people to a relatively cool Colorado. But in this scenario, high-density housing predominates and strong investments in research lead to greater efficiencies in water use.
  • Business As Usual - the economy grows slowly with anticipated spikes and falls and most Coloradans live in single-family homes. Water conservation has slowly increased.
  • Cooperative Growth - population growth is concentrated in cities and resort communities and water and energy conservation measures are willingly adopted.
  • Weak Economy - the economy struggles in Colorado and the nation as a whole; population growth is less than expected.

The SWSI Update is incorporating these planning scenarios into its estimates of the water supply gap in 2050. It is not currently understood how the Update will use the population projections quantified by DOLA.

Municipal Water Supply

How a municipality collects, stores, treats and distributes water to its customers can be a complex process. If this also includes the use of transbasin water (water diverted from watersheds west of the Continental Divide to the South Platte Basin), then this process becomes even more complicated.

For example, Denver Water, the municipal water provider for the City and County of Denver serving many communities, collects and stores its water in a complex system. The primary water sources are the South Platte and Blue rivers. Secondary water sources include the Fraser River, Williams Fork River, South Boulder Creek, Ralston Creek and Bear Creek. The water is stored in 13 main reservoirs. The largest is Dillon Reservoir with 254,036 acre-feet of active capacity, followed by Eleven Mile Canyon (97,779 acre-feet), Cheesman (79,064 acre-feet) and Gross (41,811 acre-feet) reservoirs. Additional reservoirs include Antero, Marston, Ralston, Strontia Springs, Long Lakes, Platte Canyon and Soda Lakes. Williams Fork and Wolford Mountain reservoirs are also used, primarily for water exchanges necessary to meet the needs of downstream water water rights or endangered species requirements (Citizen's Guide to Where Your Water Comes From, p.23). Transbasin water is diverted via the Roberts Tunnel Collection System and Moffat Collection System. For more information, go to the Your Water section of Denver Water's website. Denver Water and other water providers typically design their systems to provide a normal water supply even in years of drought, such as a 1-in-50-year drought, with drought restrictions imposed in severe drought.

Another example, WISE (Water, Infrastructure and Supply Efficiency), is a regional partnership that provides new supply to 10 Douglas County entities by combining unused capacities in Aurora Water's Prairie Waters Project with unused supplies from Denver and Aurora. During years that Denver and Aurora don't need all of their water supply, and when excess capacity is available in Prairie Waters, these entities can buy the unused water, which helps reduce their reliance on nonrenewable groundwater. The 10 entities are: Town of Castle Rock, Centennial Water and Sanitation District (WSD), Cottonwood WSD, Dominion WSD, Inverness WSD, Meridian Metropolitan District (MD), Parker WSD, Pinery Water and Wastewater District, Rangeview MD and Stonegate Village MD.

The treatment and conveyance of a municipality's water supply may be covered more thoroughly in an enhanced version of this story.

Municipal Water Providers

Most residents of Colorado get their water via a water provider entity. The provider may be a municipal utility, a special district, a private company or other entity type. Municipal utilities are often organized as enterprise funds that have independent budgets from the general fund of the municipality, are not-for-profit and balance rates with cost of operations and capital projects. A special district is local government entity formed to serve a single purpose, such as a water and sanitation district.

Municipalities are often served by multiple water providers. They may also have separate utilities or providers for wastewater and stormwater that have different service areas and rates.

Municipal water providers often have a water supply that comes from multiple sources, such as rivers, storage reservoirs, groundwater, transbasin diversions or reusable water. This ensures a reliable supply when one source is not available or has a lower quality.

Municipal water providers generally have a board of directors and hold public meetings. Water-related programs, such as conservation, agricultural water rentals and public education vary by entity type, size and relationship to other municipal programs.

Large water providers are required by federal law to annually publish a water quality annual report or "Consumer Confidence Report" (CCR). These are often available on the water provider's website under headings related to water quality.

Municipal Water Use

House Bill HB10-1051 was adopted by the Colorado General Assembly in 2010 and requires retail water providers that sell 2,000 acre-feet or more of water annually (termed covered entities) to report water use and conservation data on an annual basis. The goal is to improve the quantity and quality of data available that support statewide water supply planning efforts. The data are publicly available from the Water Efficiency Data Portal.

The Colorado Water Conservation Board (CWCB) was directed to develop reporting guidelines that include descriptions of customer categories, uses and measurements. The CWCB determined that the majority of water distribution systems could be classified as Potable Treated Water, Non-Potable Raw Water and Non-Potable Reuse (or Reclaimed) Water.

Within these categories, water use is designated as distributed or metered. Distributed water is the amount of water delivered to served customers. Metered water is the amount of distributed water that is metered by a provider and is calculated as distributed water minus water loss (Distributed - Loss = Metered). Water loss may occur for several reasons, including leaky pipes.

This map shows distributed potable treated water use for covered entities in the Basin for the years 2013-2017. (Note that many of the entities have not submitted 2017 data as of the last download of this data in March 2018). Water providers are color-coded by the population served and sized by the amount of water used.

Potable Treated water is then broken down into customer classes and categories typically include: Residential (Single Family and Multi-Family); Utility/Municipal Facility; Commercial, Industrial and Institutional; and Irrigation Only. Additionally, Wholesale water includes water sold by the reporting entity to another entity for resale to water users (customers). Future versions of this map may break down water use into customer classes.

The image below, from the Citizen's Guide to Colorado Water Conservation (p.3) shows that statewide, the largest municipal water use is residential, and that usage is roughly equal for indoor and outdoor purposes.

Municipal Water Use and Efficiency

Water Conservation vs. Water Efficiency: these terms are often used interchangeably but have different meanings. Efficiency is using the least amount of water necessary to achieve a result and focuses on reducing water waste. Conservation is the act of increasing efficiency and refers to methods that provide permanent water savings or a reduction in the amount of water consumed.

Cities in the South Platte and Metro basins are national leaders in water conservation and reuse (BIP, p.1-17). Municipal conservation programs have already been heavily implemented in the larger cities. This map shows water providers that have published water efficiency plans and pop-ups provide links to those plans. According to Colorado's Water Conservation Act of 2004, water providers that deliver at least 2,000 acre-feet of water per year to their customers are required to file a water efficiency plan with the Colorado Water Conservation Board (CWCB). The CWCB provides Water Efficiency Grants to eligible entities to develop water efficiency and drought plans, implement water conservation goals and educate the public about water conservation.

Water conservation is further categorized as passive or active conservation. Passive conservation is conservation that occurs through natural trends, such as the replacement of older household fixtures (toilets, showerheads, dishwashing machines, clothes washers) with new water-efficient models. Active conservation consists of programs that proactively drive change and require a customer's participation. These include rebates, audits and leak detection, among others. It has been estimated that 160,000 to 461,000 acre-feet of water could be saved statewide by 2050 through active municipal conservation measures and 154,000 acre-feet of water saved through passive conservation measures (Citizen's Guide to Colorado Water Conservation, p.2)

Additional reuse of water supply components including nontributary groundwater, the consumptive use component of changed native water rights and transbasin imports is possible but may affect downstream water availability, water management flexibility and interstate water compact compliance (BIP, p.1-17).

Colorado WaterWise, a non-profit organization, has information about resources for the efficient use of urban water.

Agricultural Entities

Agriculture plays a key role in the economy of the South Platte and Metro basins. There are approximately 1.38 million acres of irrigated land in the basin (including the Republican Basin); this amounts to 40% of Colorado's irrigated acres (BIP, p.2-20).

In 2012, seven of the top ten agriculture-producing counties in Colorado were located in the South Platte Basin. Agricultural sales in the Basin for that year were $5.8 billion, representing 75% of the statewide total (BIP, p.2-15). These counties, in order of production, are: Weld, Yuma, Morgan, Logan, Kit Carson, Washington and Phillips.

With the exception of dryland wheat, most of the agricultural production in the Basin (and the State as a whole) requires irrigation to generate sufficient crop yields. Within the Basin, agriculture accounts for 85% of total water diversions (Colorado Water Plan, p.3-13).

Agriculture is the dominant water user in the Basin and is also one of the primary sources of water as water rights are reallocated from agricultural to municipal supplies.

Agricultural Entities

This map shows the 500 ditch service areas in the Basin. The largest, FRICO (Farmers Reservoir and Irrigation Company)/ Barr Lake Ditch, serves an area of over 100,000 acres. Service areas are not typically fully irrigated. Some areas within the service area may have been dried up, water rights transferred to urban use or perhaps were never irrigated because of the land use type. Ditch service areas cover many Front Range areas that are now urbanized. The water rights for these ditches are often transferred to municipal water providers, in which case ditch company board positions may be filled by municipal water providers.

To divert water from a river into a ditch or canal for agricultural use (or urban use), diversion structures called headgates are installed in the river. Headgates are typically metal gates that are raised and lowered to allow a controlled amount of water to flow into a ditch or canal. The amount of diverted water is measured and data are maintained by the Division of Water Resources. Ditches and canals often require a dam or inlet structure on the river to help push water into the ditch or canal. Canals and ditches move diverted water using gravity; they often follow the topography of the land and may wind for many miles to their final point of delivery. At certain points along a ditch or canal, additional headgates release water into smaller ditches called laterals or else into pipelines (Citizen's Guide to Where Your Water Comes From, p.26-27). Ditch rights of way may be used for trails and open space; urban ditches may deliver raw water to parks and natural areas.

Most ditches in Colorado are owned by the water users themselves. Small ditches are often owned in partnership by a handful of users. Medium and large ditches are often owned by shareholders of mutual ditch companies, which are private, non-profit organizations formed to distribute water to their member-owners. Owners generally pay a fee to the ditch company based on the share of water that they own. Shareholders also pay annual assessments to cover the costs of operations and maintenance (Citizen's Guide to Where Your Water Comes From, p.27).

The Ditch and Reservoir Company Alliance (DARCA) provides resources for ditch and reservoir companies, irrigation districts, laterals and private ditches.

Changes in Agricultural Lands

Agricultural land use has been changing over time for a number of reasons, including:

  • Conversion from flood irrigation to sprinkler irrigation (see following section)
  • Conversion of agricultural lands to urban areas
  • Conversion of irrigated agricultural to non-agricultural or dryland farming because water rights have been transferred off the land

When agricultural lands are converted to urban use, the term "buy and dry" is often used. This refers to a municipal water provider purchasing agricultural water rights and transferring the consumptive use portion of the right to municipal use. Quite often this process involves storing the water in a reservoir, and perhaps transitioning over time by using rental programs and other options to allow farming to continue. Return flows must be maintained at historical averages as if the land were still in agricultural production. Municipal entities typically don't need the water every year but are purchasing water to plan for growth and as an insurance policy against drought and climate change.

The image on the right shows how agricultural land use has changed over time at the boundary of irrigated agriculture and urban area, in this case near Greeley. Click on the arrows in the middle of the image to move from an image from 2005 to one from 2017. Note the adoption of sprinkler irrigation over time and urban growth onto agricultural areas. Whether the water that was used for agriculture can fully supply urban growth depends on the land use practices of the urban growth.

The impacts of urban growth on irrigated lands in Colorado are illustrated in these Colorado Irrigated Acreage visualizations.

Agricultural Water Use and Efficiency

Because agriculture is the dominant water user in the Basin, it is a common perception that if agricultural entities did a better job of conserving water then the anticipated gap in future water supplies could be met. One of the ways in which water can be conserved is through the use of more efficient irrigation systems, such as center pivot sprinklers or drip irrigation.

There are several reasons to switch to more efficient irrigation methods (Colorado Ag Water Alliance (CAWA) Brochure):

  • These methods do a better job of delivering water to the crop, which results in the crop being more evenly irrigated, which increases yield
  • These methods typically require less labor
  • These methods leach less water through the soil, so less money is spent on fertilizer and herbicides

The image at right shows the changes in irrigated acreage in the Basin. Each circle represents a diversion structure and is color-coded by the water district it is in. The x-axis represents the number of irrigated acres and the y-axis represents the number of acres irrigated by sprinklers using surface water and groundwater (circles at the bottom of the y-axis therefore represent flood irrigation). Circles are also sized by the percentage of acres irrigated with groundwater. To run the visualization, mouse-over the image at right and then click on the link in the popup. Key observations include:

  • The use of sprinkler irrigation began in the 1970s
  • Water districts 01 (South Platte River from Greeley to Balzac) and 02 (South Platte River from Denver to Greeley) contain the most sprinkler-irrigated acreage and overall contain the most irrigated acreage
  • Water districts 01 and 02 contain the largest numbers of acres irrigated via groundwater

For more detail on how to use the visualization, click on the Documentation tab within the visualization.

The table below shows the changes in flood- versus sprinkler-irrigated acreage from 2005 to 2015 for several crops in the Basin. Note that the total amount of irrigated acreage has declined by approximately 20,000 acres.

2005 Acreage 2015 Acreage
Crop Type Flood Sprinkler Flood Sprinkler
Alfalfa 120,079 116,995 72,057 127,983
Barley No data No data 3,812 1,275
Corn 148,858 134,900 94,653 199,203
Dry Beans 18,641 10,016 2,804 3,055
Grass Pasture 144,481 16,054 168,945 20,215
Orchard without Cover 1,298 72 No data No data
Potatoes No data No data 147 568
Small Grains 35,510 23,144 4,374 5,080
Sod Farm 2,148 6,044 No data No data
Sorghum Grain No data No data 3,107 2,845
Sugar Beets 12,415 12,751 7,640 13,062
Sunflower No data No data 1,643 2,220
Vegetables 15,947 10,124 331 328
Spring Wheat No data No data 35,086 38,808
Total 499,376 330,099 394,601 414,642

Source: Division of Water Resources, GIS Data Library Division 1 Irrigated Lands 2005 and Division 1 Irrigated Lands 2015.

The Colorado Ag Water Alliance (CAWA) is composed of agricultural leaders committed to the preservation of agriculture through the wise use of water resources. Members represent major facets of production agriculture (such as the Colorado Corn Growers Association, Colorado Dairy Farmers and Colorado Cattlemen's Association), as well as partner organizations such as the Colorado Water Institute, Colorado State University, Colorado Department of Agriculture and the Colorado Water Conservation Board.

Environmental Entities

The value of water is often quantified from the perspective of consumptive water uses such as agriculture and municipal supply. However, water that remains in a stream also has value for environmental and recreational (E&R) uses, also sometimes called non-consumptive uses, although E&R uses do consume water such as through evaporation from water surfaces and transpiration from vegetation. The non-consumptive use of water provides benefits to fish, wildlife, riparian habitat, wetlands and recreation. These uses also have economic value and are some of the important qualities that people associate with Colorado.

It is perhaps better to think of environmental entities as attributes rather than entities. In the South Platte and Metro basins, these attributes include the following (Basin Implementation Plan, p.2-25):

  • Rare aquatic-dependent plants
  • Significant riparian plant communities
  • Plains fish that are either state-endangered, threatened or species of special concern, such as: Brassy Minnow, Common Shiner, Northern Redbelly Dace, Plains Minnow, Stonecat, Suckermouth Minnow, Iowa Darter and Plains Orangethroat Darter
  • State-endangered, threatened or species of special concern, such as: Boreal Toad, Lake Chub, River Otter, Yellow Mud Turtle, Northern Leopard Frog, Northern Cricket Frog, Plains Leopard Frog, Preble's Meadow Jumping Mouse, Common Garter Snake and Wood Frog

As part of the SWSI Update, the Environmental and Recreational Database (formerly the Nonconsumptive Needs Database) will be updated and will build upon these attributes. For more information see the SWSI Update Environmental and Recreational Methodology Fact Sheet.

E&R attributes are particularly important at specific locations and the assessment of E&R water requirements and supply are typically evaluated based on stream reach and local basin scale.

Environmental Flow Protection

The primary means of protecting environmental and recreational attributes is through the protection of flows. A range of flows are generally needed to protect aquatic species and their associated habitats. For example, minimum flows are the minimum amounts of water needed to preserve the aquatic environment, whereas peak flows can be cues for fish to spawn, flush sediment and deposit sediment to create new habitat.

The Colorado Water Conservation Board's Instream Flow Program is tasked with the "appropriation, acquisition, protection and monitoring of instream flow and natural lake level water rights to preserve and improve the natural environment to a reasonable degree". This map shows CWCB decreed instream flow reaches in the South Platte and Metro basins. Selecting a month on the right side of the map shows the decreed flow amounts for each month of the year. Hover over a stream reach to obtain more information, such as the number of miles of stream that are protected.

Instream flow rights are often junior to water rights that provide water supply for agricultural and municipal uses and therefore streams with instream flow rights can completely dry up. In other cases, a senior water right lower in a basin can draw water through a reach and help provide instream flow. The nonprofit Colorado Water Trust is an organization that helps improve flow conditions within the water rights system.

Environmental Entities

Entities do exist that provide stewardship, conservation or other services to protect and enhance environmental attributes. The Colorado Watershed Assembly maintains a directory of watershed groups. Other entities include The Nature Conservancy, Ducks Unlimited and Trout Unlimited, among others. Additionally, The Greenway Foundation specifically focuses on efforts to reclaim the South Platte River and its tributaries.

Additionally, the Open Water Foundation, in coordination with the CWCB, created this interactive visualization of watershed plans in Colorado. The State is divided into Hydrologic Unit Code (HUC) 8 watersheds and the number of plans in each watershed is indicated. By choosing a watershed ("Select Basin" dropdown), it is possible to view the names of watershed plans, who wrote them (Organization), and links to the plans. Many of the organizations are local river coalitions whose missions are to protect and/or restore their local watershed. The dataset for this visualization could be updated to provide additional resources and planning areas can be overlaid with stream reaches.

The South Platte Basin has the highest concentration of watershed plans in this dataset.

This visualization can also be viewed here.

Recreational Entities

Recreational entities are industries and organizations that benefit from and advocate for an environment that sustains recreational uses, which are often closely tied to environmental conditions such as flows in rivers and lake levels. Recreational opportunities often benefit individuals. Water resources data that helps to understand recreation includes locations of recreational opportunities such as boating, camping and fishing and analyses of water data, such as number of boating or fishing days in each year and trends.

The SWSI Update project is updating the Environmental and Recreational Database (formerly the Nonconsumptive Needs Database) to help understand recreational water needs and issues. More information may be added to this page once the SWSI Update is complete. For more information see the SWSI Update Environmental and Recreational Methodology Fact Sheet.

Updates to this page may include some discussion of rafting companies. The primary rivers for the rafting industry in the basin are the Cache la Poudre River and Clear Creek.

Important recreational entities include Trout Unlimited, Ducks Unlimited, American Whitewater and the National Audubon Society. Colorado Parks and Wildlife also implements programs that support recreation and manage environmental resources.

Recreational attributes considered by the SWSI Update include Gold Medal streams, Colorado Outstanding Waters and Wild and Scenic Rivers (a 70-mile stretch of the Poudre is currently the only Wild and Scenic River in Colorado).

Industrial Entities

Industrial entities may also be large water users, especially in some areas. Industries may receive water from utilities and other water providers or may provide their own water as a "Self-Supplied Industry (SSI)". Examples of industries that require water, with potential data sources, include:

  • Dairy industry -- water is used directly and dairies also have large livestock feed inputs, with associated agricultural water demand. A potential data source is Dairy MAX (formerly the Western Dairy Association, which has merged with Texas-based Dairy MAX).
  • Cattle industry and feedlots -- potential data sources are the Colorado Cattlemen's Association and Colorado Livestock Association.
  • Brewing industry -- a common efficiency metric is gallons of water used per gallon of beer. Potential data sources are the Brewers Association, Colorado Brewers Guild and Colorado Craft Brews.
  • Skiing industry (snowmaking) -- this use is generally non-consumptive, but water demand in the winter is at a time when streams have low flows.
  • Energy and mining (which includes aggregate) -- some companies hold large conditional water rights such as for oil shale development that could have a major impact.
  • Thermoelectric power generation -- water is used for cooling.
  • Oil and Gas -- potential data source is the Colorado Oil and Gas Association.

Increasing water use efficiency in industry can help reduce statewide water demand. Reducing water input to industry also reduces costs to the industry.


This Water Entities story has been created during the South Platte Data Platform Project. This story and all of its content can be found at the swsi-story-sp-entities repository on GitHub. See the README file in the repository for an explanation of data sources and processing.

Additional information can be found at the following:

Statewide Water Supply Initiative (SWSI) 2004 (PDF) and SWSI 2010

SWSI Update

South Platte Basin Implementation Plan (PDF)

Colorado Water Plan

South Platte Basin Roundtable

Metro Basin Roundtable

Colorado Water Conservation Board Water Supply Planning Section

Questions or feedback? Contact Lacey Williams (

Last update: October 15, 2018


Tractor image available from Pexels.

Stream image, white water rafting image, oil well image and image of Rocky Mountain National Park available from Pixabay.

Horses digging ditch courtesy of the Poudre Heritage Alliance.


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Additional instructions for viewing the story include:

  • The content is best viewed on a relatively large display and has not been optimized for mobile devices.
  • If content does not seem to fit in the browser window, maximize the window size or use Ctrl - to reduce font sizes. Ctrl + can be used to increase font sizes.
  • For interactive maps, the default behavior for the mouse scroll is to advance the story page. Click on the mouse icon () in the map to change mouse scrolling to zoom behavior. Once changed, the behavior will apply only to the specific map.
  • Interactive maps can be repositioned by holding the left mouse button and dragging the map.
  • Scrollable text areas are provided in some pages and can be scrolled by dragging the text area scroll bar.
  • External pages are indicated with a graphic and will be shown in a separate tab when selected.
  • Links to sections within the story and external pages are generally the same font color as normal text but are indicated with underlines.
  • Visualizations that will slow down the story are linked to as separate pages and will be shown in a different tab when selected. Mouse over the image to see a popup link to the separate page.
  • Interactive maps provide popups to view data. If the popup flashes, drag the map to reposition it so that the popup does not occur in the same area as the map instruction box.
  • Some maps allow clicking on map markers to access links to additional data.

Interactive graphs typically behave as follows:

  • Zoom into the graph either by holding the left mouse button and drawing a rectangle on the graph or by clicking/holding/dragging the buttons on either end of the time slider in the overview graph below the main graph.
  • Once the time slider "window" (light blue shaded area in the overview graph) has been narrowed, use the mouse to drag the shaded area to another time period. Or, click in the overview graph on either side of the shaded area to center the graph period on the clicked point.
  • To fully zoom out, drag the ends of the shaded area in the overview graph to the margins of the graph.
  • All time series can be selected or deselected by clicking on the "Select All Series" or "Deselect All Series" buttons below the graph. It is also possible to individually select or deselect one time series at a time by clicking on the time series name in the legend.