Grand Lake is Colorado’s largest natural lake with a surface area just over 500 acres with a depth of 265 feet.  Early glaciers originating in the North Inlet and East Inlet valleys formed moraines along the north western and south western shores of the lake, as well as the moraine at the western end of the lake. 

Natural flows into Grand Lake come from the North and East Inlet streams, carrying snowmelt from watersheds extending to the Continental Divide, high in Rocky Mountain National Park largely undisturbed by people.  The natural outlet flow from Grand Lake was through a break in the moraine at the western end of the lake, now spanned by a pedestrian bridge at Point Park.  The flow out of Grand Lake formed the headwaters of the Colorado River (formerly called the Grand River).

Prior to the construction of the Colorado-Big Thomson project, the area now filled by Shadow Mountain reservoir was a broad, flat valley through which the Colorado River headwaters meandered.  In this meadow, the flow out of Grand Lake was joined by flow from the North Fork of the Colorado River, emanating from the Kawuneeche Valley in Rocky Mountain National Park. 

The islands which are now visible near the southern end of Shadow Mountain reservoir are terminal moraines, created by the advancing and recessing of a massive glacier that emanated from the Kawuneeche Valley and blended with ice from Grand Lake’s glaciers.  At one time in the distant past, there was likely a shallow lake in this valley partially blocked by these terminal moraines and fed by the receding glaciers. 

In contrast to the residual shallow lakes that often form after glacier advance and recession, Grand Lake is quite unique in its depth, noted earlier as 265 feet.  Thus it is likely that Grand Lake first existed as a deep crater lake, accounting for its depth, whose shores have been subsequently shaped by overriding glaciations.

The Colorado-Big Thompson (C-BT) Project, funded by the United States Senate in Senate Document 80 (SD80) and approved in 1937, changed the natural landscape and the historical flows of Colorado River water forever.  A well-written description of the Colorado-Big Thompson Project can be found online at the Bureau of Reclamation website.  The History section is particularly interesting as it describes the organized environmental resistance that the C-BT Project had to overcome in its infancy.

As part of the C-BT, Granby reservoir was constructed to collect runoff from a much larger watershed.  The Farr pumping plant on the north shore of Granby reservoir was built to pump water into Shadow Mountain reservoir, which was constructed in the same era.  As water is pumped into Shadow Mountain reservoir, water is forced backwards into Grand Lake through the old Colorado River headwaters (now a channel) connecting these two distinctly different water bodies.  The Adams tunnel, constructed as part of the C-BT, allows water to flow from Grand Lake underneath the Continental Divide eventually feeding Horsetooth and Carter reservoirs among many others on Colorado’s eastern slope.

While alleviating water supply problems for Colorado’s eastern slope, unanticipated consequences of the C-BT Project are now having harmful effects on the greater Grand Lake region. 

As approved by the Senate in 1937, Grand Lake was to be preserved and treated as a scenic resource as well as a recreational resource.  The language of SD80 mandated that the project be operated “To preserve the fishing and recreational facilities and the scenic attractions of Grand Lake, the Colorado River, and the Rocky Mountain National Park”.

SD80 is a synopsis of a much larger document developed by the Bureau of Reclamation to justify the C-BT project.  In the Bureau’s 1937 Report on Plans and Cost Estimate Colorado-Big Thompson Project, Volume 4, they state: “The approach to the western gateway of Rocky Mountain National Park will be along the shores of Shadow Mountain Lake and a view of clear water…”

Simple observations of conditions today show that the “clear water” of Shadow Mountain reservoir is often fouled with weeds, silt, algae and algal toxins, all of which are pumped into Grand Lake resulting in degradation rather than preservation:

In the early 1930s when the C-BT Project was being proposed, the understanding of lake behavior was only a developing science with much to be learned and with unintended consequences in store as a result.  Being shallow with an average depth of less than ten feet, the Petri dish design of Shadow Mountain reservoir has proved to be an ideal breeding ground for weeds, algae and algal toxins resulting in very poor water clarity during peak tourism season.  Worse, those newly added contaminants now degrade water quality and clarity of Grand Lake, and even appear far downstream at the water treatment plants supplying drinking water to eastern slope towns.

In 1941, a world-renowned lake scientist from the University of Colorado named Robert Pennak measured the clarity of water in Grand Lake at 9.2 meters (over 30 feet) using a simple device call a Secchi disk.  He noted that after the start of C-BT pumping the clarity decreased and that lake water quality had been “irreparably harmed”.  Today, we now measure Grand Lake water clarity at 2 meters or less when pumping flow is at a maximum.  Further, there is convincing data that Grand Lake clarity is at its best when there is no pumping and at its worst with greatest pumping:

The graph above is one of many that show Secchi depth readings averaging 4 meters when there has been no forced pumping in the prior weeks, degrading to less than 2 meters following forced water transfers.

The promises of preserving Grand Lake and of clear water in Shadow Mountain reservoir seem to have evaporated with indifference, as these water bodies are now regarded by many as simply convenient conduits to move water.

The Greater Grand Lake Shoreline Association is committed to the mission of preserving Grand Lake and its surroundings.  We have been analyzing data and information often collected by others in our attempt to recapture those promises made in Senate Document 80 and in the Bureau of Reclamation’s background documents.  And we think that we are making some progress, as described below.  But we will need help.  What follows is a brief chronicle of post-C-BT construction events, leading to the water quality work we are now trying to foster.

Post-C-BT-Construction History

Although approved in 1937, much C-BT construction was put on hold during WWII as much more pressing matters naturally consumed all federal resources.  By the late 1940s things were back on track.  The C-BT system began its operations in full scale in the early 1950s.

Water quality problems in Grand Lake appeared immediately after the startup, with the first rounds of algae blooms attributed to nutrient influx from the recently-flooded meadows now under water at Shadow Mountain reservoir and Granby reservoir.  These meadows of course contained hay and weeds as well as cow and elk poop that led to the first major non-natural influx of nutrients into Grand Lake.

Shortly thereafter, deficiencies in the Town of Grand Lake’s then-primitive sanitation treatment facilities became quite evident.  Water treatment lagoons processing Town wastewater originally discharged into the headwaters of the Colorado River at a time when there were few downstream users to notice problems with the discharge.  Now however, discharge into the north end of the new Shadow Mountain reservoir turned right around and flowed into Grand Lake where there were many people relying on Lake water for drinking water and residential uses.  This “right back at you” discharge led to further algal blooms and bacterial problems for the surrounding community.

It took decades (until the early 1980s) for Grand Lake residents to adequately address that problem.  With federal grant help, the Three Lakes Water and Sanitation District was formed.  Sewer mains were installed around Grand Lake and along the shores of Shadow Mountain reservoir replacing septic systems, and new water treatment lagoons were constructed to the east of Granby reservoir.  By design, effluent from the lagoons did not flow into Granby reservoir, but was diluted and transported through irrigation canals and into Willow Creek, eventually reaching the Colorado River near Windy Gap.  In 2003, the Three Lakes Water and Sanitation District replaced the lagoon system with a state-of-the-art indoor sanitation facility, further improving the wastewater treatment process.

In the early 1980s the Windy Gap project was added to move additional water collected from the Fraser River up into Granby reservoir, roughly doubling the size of the C-BT collecting watersheds.  Prior to Windy Gap, the human influences on nutrient supplies to reservoir water were much more limited.  Grand Lake’s natural watershed emanates from Rocky Mountain National Park; Shadow Mountain reservoirs natural collection includes that from the Kawuneeche valley, also in Rocky Mountain National Park; and Granby reservoir collects water from the Indian Peaks wilderness area from its eastern watershed.  Windy Gap, however, collects not only natural runoff but also nutrient-rich effluents from large human-influenced areas, including effluents from sanitation systems in Winter Park, Fraser, Tabernash and Granby.  Further nutrients are added to the Fraser River by runoff from fertilizer applications on golf courses including Pole Creek, the Headwaters Golf Course at Granby Ranch, and Grand Elk.  Soon another new golf course at Orvis Shorefox will contribute its share of nutrient rich runoff to the Colorado River just above Windy Gap.  Windy Gap pumps this water up into Granby reservoir; the Farr pumping at Granby reservoir plant pumps it into Shadow Mountain reservoir;  Shadow Mountain reservoir then serves as a conduit for this water, acting as a Petri dish to grow weeds and algae prior to flushing these materials into Grand Lake and then under the Continental Divide through Adams tunnel.

It is hard to comprehend the massive quantity of water moving through Grand Lake, even while standing on the pedestrian bridge over the channel from Shadow Mountain reservoir.  At maximum flow through the Adams tunnel conveys roughly 1000 acre-feet of water daily.  This is equal to a water column 1000 feet high covering a football field, and is equivalent to replacing the upper two feet of Grand Lake every day.

The capacity of Shadow Mountain reservoir is about 18,000 acre-feet, so at maximum flow a volume equal to the entire contents of that reservoir can be moved into and through Grand Lake every 18 days.

The capacity of Granby reservoir is roughly 550, 000 acre-feet when full.  About one-half of that enormous water volume is moved into and through Grand Lake each year (the C-BT system does operate at full flow on an annual basis).

Currently the Windy Gap firming project is in an evaluation stage, with a proposal to move yet more water from the Windy Gap basin up into and through Granby reservoir to Shadow Mountain reservoir and Grand Lake.  The draft Environmental Impact Statement for this project is due later in 2007, and GGLSA will add our displeasure to the voices of many others in opposing this project.

Recent GGLSA Actions

In 2004, the Grand County Water Information Network (GCWIN) collected data quantifying a major bloom of algae originating in Shadow Mountain reservoir. Anabaena is a form of blue-green algae (also known as Cyanobacteria) that is harmful when concentrations exceed certain levels.  For drinking, the World Health Organization (WHO) recommends less than 2000 cells/milliliter; at 20,000 cells/ml the WHO recommends that information be provided to swimmers and recreational water users; at 100,000 cells/ml the WHO recommends restrictions on bathing at beaches and public education campaigns to alert users to risk; at even higher levels surface scums will likely form and present high risk of human illness and animal poisonings. 

Measured levels of Anabaena in Shadow Mountain reservoir reported by GCWIN in 2004 exceeded 50,000 cells/ml.  The bloom repeated in 2005, exceeding 30,000 cells/ml.

GGLSA has written an overview paper on this subject that can be found on our website white paper.  Although this overview was distributed to local, county and state officials as well as a long list of agencies, the only response came from Grand County officials who share the concern that a rare gem (Grand Lake) may eventually be lost without action.

Discussions with Grand County officials led to the joint sponsorship of a scoping study to determine whether there might be less-harmful means of moving water to the eastern slope water users without using Grand Lake as a conduit.  With co-funding from Grand County, from the Three Lakes Watershed Association, and from the Northern Colorado Water Conservancy District (NCWCD), GGLSA arranged a contract with the consulting firm of McLaughlin-Rincon to conduct the study.  The McLaughlin-Rincon report identified several interesting possibilities including a new tunnel or an underwater pipeline, either of which could transport water to the Front Range without the negative influences on Grand Lake. 

Estimated costs of these alternatives range from $15 million for an underwater pipeline to $60 million for a new tunnel.  While seemingly a large amount of money, we note that if spread over the base of 750,000 NCWCD customers this would amount to a one-time fee of $20 to $80 per user.  This is negligible, however, when compared to user water tap fees on new homes along the Front Range which average over $15,000.  It is also negligible when compared to the projected cost of the Yampa River diversion that is under study by NCWCD.  The cost of that project is estimated to be in the billions of dollars.

NCWCD has made no response to the McLaughlin-Rincon report, although they funded one-quarter of the study.  The Bureau of Reclamation has responded, in a letter dated February 8, 2007, stating:  “To change the constructed facilities as envisioned in the McLaughlin-Rincon report would require Congressional authorization and a funding source.”  They go on to recommend that:  “We should all work together to share available information so that we can jointly reach an informed conclusion and develop any needed solution.”  This is of course aligned with the goals of GGLSA.

As the Bureau of Reclamation was developing their response, GGLSA was working to understand the process of setting water quality standards in Colorado.  In January of 2007 we were invited to make a presentation to the staff of the Colorado Department of Public Health and Environment (CDPHE).  CDPHE includes the Colorado Water Quality Control Commission and the Division of Water Quality under their umbrella.  The GGLSA presentation as presented at the  CDPHE  meeting can be viewed here.  After the meeting, CDPHE scientists followed up on our suggestion to examine whether a correlation exists between clarity and pumping, and they found indeed that clarity degrades with pumping.  In a letter dated May 8, 2007 Steve Gunderson (Director of the Water Quality Control Division of the CDPHE) wrote:  “Because of the uniqueness of Grand Lake as the largest natural lake in Colorado, the Water Quality Control Division believes that a site-specific water quality standard that establishes a water clarity goal is worthy of consideration.”  The full text of this letter can be found at in CDPHE Response Letter. 

As a result of the encouraging response, Grand County officials have agreed to be the focal point agency in driving the process of setting these standards.  A kick-off meeting was held at the Grand County Courthouse on July 13, 2007 with Lurline Underbrink-Curran (designated as SD80 coordinator for Grand County) presiding.  Presentations were made by John Stahl of GGLSA , by (a very large PowerPoint Presentation)  Dr. John Reutter of the Tahoe Environmental Research Center (TERC), and by Sarah Johnson (manager of the Standards department of CDPHE).  All three Grand County Commissioners were present for this meeting, which also involved representatives from NCWCD, the Bureau of Reclamation, the US Forest Service, the Colorado Department of Wildlife, the Colorado River Water Conservancy District, the Northwest Council of Governments, Trout Unlimited, and other stakeholders. 

At the conclusion of the meeting, Lurline Underbrink-Curran addressed the audience and stated on behalf of the Commissioners that Grand County intended to drive the water quality standards process as the lead agency.  She further stated that while the County hoped that NCWCD and the Bureau of Reclamation would participate in the collaboration, the process would be driven forward in any event.  GGLSA regards the County’s leadership and forcefulness to be a significant turning point in our efforts to restore Grand Lake. 

On July 14, 2007 GGLSA held its annual all-members meeting with nearly 50 people present.  John Stahl made a brief overview presentation on Grand Lake.  The presentations from John Reutter of TERC and Sarah Johnson from CDPHE were repeated for all members to hear, and Nicole Seltzer of NCWCD presented an overview of the on-going nutrient study that NCWCD has in process. 

As further evidence of the seriousness of the County leadership, they have hired Katherine Morris (trained at the Colorado School of Mines in Golden) to coordinate the activities necessary to meet critical deadlines in the CDPHE process.  There is a scoping meeting in October of 2007 to present the intent to set standards for Grand Lake, and then a series of meetings in preparation for the June 2008 CDPHE meeting in which standards are set.  CDPHE will want proof that whatever standards are set can be achieved.  Katherine is already quite busy coordinating the meetings necessary to present a case at CDPHE, and GGLSA members are participating in this County-led effort.

Unfortunately, conditions in Shadow Mountain reservoir continue to deteriorate.  The photo below was taken on August 9, and show the ugly influx of poor quality water entering Grand Lake under the Rainbow Bridge:

It is obvious that we have a lot to do before our goal of restoring 9.2 meter clarity in Grand Lake can be achieved.

Key agencies and entities

There was a time when the citizens on and around Grand Lake could have understood and managed lake clarity on their own.  But post-C-BT, we collaborate with a long list of agencies that make decisions affecting Grand Lake and Shadow Mountain reservoir.  These include:

The U.S. Department of the Interior, Bureau of Reclamation:  This is the agency that proposed, designed and built the C-BT and is responsible for operation of all facilities.

Northern Colorado Water Conservancy District:  This quasi-government agency was created as the Northern Colorado Water Users District in SD80, and is responsible for scheduling water deliveries and moving water to assure the constant availability of water to their constituency (750,000 users, according to their website).

The U.S. Department of Agriculture, United States Forest Service:  USFS now has responsibility for Shadow Mountain reservoir as part of the Arapahoe National Forest.

The U.S. Department of the Interior, National Park Service:  NPS was an early opponent of the C-BT, but eventually approved the construction of the Adams tunnel which passes under Rocky Mountain National Park.  The North and East Inlet streams providing source water to Grand Lake originate in RMNP.

The U.S. Army Corps of Engineers:  The Corps of Engineers regulates certain activities on all water bodies in the United States.  If you want to put in a dock or dredge around an existing dock, you will need approvals from the Corps as well as the Town of Grand Lake and/or Grand County.

The U.S. Department of the Interior, U.S. Geological Survey:  USGS water quality scientists are frequently found surveying water quality on the lakes as part of their natural resources programs.

United States Environmental Protection Agency:  The EPA has responsibility under the Clean Water Act to enforce the laws preventing degradation of water bodies.  Water quality standards are to be set by the individual states, however.

State of Colorado Department of Public Health and Environment:  CDPHE has the authority to establish standards for Colorado water bodies through its Water Quality Control Commission and its Division of Water Quality.

State of Colorado Division of Wildlife:  The DOW has responsibility for fish and wildlife protection not only in the lakes but also in the streams that flow into and out of the lakes.

Grand County government:  The Grand County Commissioners have been especially helpful with water quality issues in our area, and they have appointed the County Manager, Lurline Underbrink-Curran, as Coordinator for SD80 matters.  The County is currently coordinating the development of site-specific water quality standards for Grand Lake.

Grand County Water Information Network:  Information about water quality is collected and disseminated to all other agencies and to concerned citizens.

Town of Grand Lake:   Grand Lake Village encompasses most of the southern and eastern shores of Grand Lake, and is responsible for public activities within their jurisdiction.

Three Lakes Watershed Association: 3LWA is a citizens group that represents the community in many water quality activities.  Most recently, they have pressed for an annual winter drawdown of Shadow Mountain reservoir as a means of controlling weed growth.