KNOW YOUR SNOW: UNDERSTANDING THE IMPORTANCE OF COLORADO’S SNOWPACK TO WATER AVAILABILITY IN THE AMERICAN SOUTHWEST – February 19, 2020

Presentations were made by Colorado River District Deputy Chief Engineer Dave Kanzer and Dr. Jeffrey Deems, Ph.D. Research Scientist, CU-Boulder topics included:

  • Updates on current snowpack and conditions
  • The latest research in snow science, which defines our water supplies on Colorado’s Western Slope
  • Snow hydrology and its impact upon our water supplies in the face of our warming climate

Link to PowerPoint Presentation

We received some great questions from participants that we, unfortunately, did not have time to discuss during the Q&A session. With this in mind, the River District’s team compiled those questions and worked to provide answers below. 

Please let us know if you have additional questions or would like more information on a specific subject.

A: The Colorado River District only operates the Central Colorado Mountain River Basin (CCMRB) cloud seeding program. The CCMRB does not operate within the Gunnison Basin; however there are seeding operations in the Crested Butte area within the Gunnison Basin that are subject to a separate permit that is operated by the Upper Gunnison Water Conservancy District.

A: The Colorado River District only operates the Central Colorado Mountain River Basin (CCMRB) cloud seeding program. The CCMRB does not operate within the Gunnison Basin; however there are seeding operations in Montrose and Ouray county area within the Gunnison Basin that are subject to a separate permit that is operated by the Upper Gunnison Water Conservancy District; these operations occur mostly above 8500 feet above mean sea level. For the sake of privacy and safety of property owners and operators and for associated proprietary reasons, we are not able to provide any information related to specific locations of cloud seeding equipment.

A: For the sake of privacy and safety of property owners and operators and for associated proprietary reasons, we are not able to provide any information related to specific locations of cloud seeding equipment.

A: Silver iodide, even when atomized in the heating process, remains a solid and is not converted to a gas. So silver iodide, in and of itself, is not a climate-warming agent in any way. The material used in the heating process, however, is propane, which when burned releases a small amount of carbon dioxide, which is an identified greenhouse gas. The amount of propane utilized and associated carbon dioxide produced is minimal and less than an average vehicle being driven in a comparable time frame.

A: Thanks for the question, you are correct in that snow density directly influences the calculation of snow water equivalent (SWE). We have estimated the density fields that ASO produces to have an error on the order of 15%, though this tends to decrease later in the melt season as the snowpack densifies everywhere. The great majority of variation in SWE across the landscape comes from variations in snow depth, with snow density varying in a much narrower range of values. Since we are directly and accurately measuring snow depth, that give us a great head start towards an accurate SWE map, and the 15% density error has a minor effect on the overall SWE values.

A: The short answer is yes, although this is outside the scope of this presentation. There are numerous forest management studies that examine the impact of vegetative cover on watershed yield. For Colorado-specific studies and investigations, we would direct you to https://csfs.colostate.edu/2017/07/21/csfs-releases-report-linking-colorados-water-resources-forest-management/

A: Dr. Jeffrey Deems, Ph.D. Research Scientist, CU-Boulder https://nsidc.org/research/bios/deems.html and David ‘DK” Kanzer, Deputy Chief Engineer, Colorado River District https://www.coloradoriverdistrict.org/staff/

A: independent research indicates that snow fall can be enhanced by 0-15% per storm, depending upon specific conditions, such as the amount of available supercooled liquid water in the cloud system, the temperatures, cloud elevation, uplift and prevailing wind direction. For example, an unseeded storm that would otherwise produce 10 inches of snow, could be enhanced by up to an additional 1.5 inches of snow under optimal seeding operating conditions.

A: Yes most of the data shown in the webinar are available to the public at the following site: https://nsidc.org/data/aso/data-summaries. Most of the images shown were custom-produced for presentation. Please contact Dr Deems directly at jeff.deems@nsidc.org and https://nsidc.org/research/bios/deems.html

A: There is an active cooperative weather observation network in the area, called CoCoRaHS, this is an acronym for the Community Collaborative Rain, Hail and Snow Network. CoCoRaHS is a unique, non-profit, community-based network of volunteers of all ages and backgrounds working together to measure and map precipitation (rain, hail, and snow). Please see https://www.cocorahs.org/Content.aspx?page=snow for more information. Additionally, the Community Snow Observations effort (https://communitysnowobs.org/) collects citizen science data to support NASA snow science efforts.

A: The Colorado River District is an active cooperator with many entities, such as the Airborne Snow Observatory, either directly or through associations with state and federal agencies. The data produced by these snow science entities are essential to the mission of sustainable water management for the Colorado River District. Specifically, the Colorado River District utilizes the latest snow data sets developed through new technologies and analyzed using state of the art modeling tools both directly and indirectly with our partners throughout the Colorado River Basin.

A: The density of snow is an important parameter that is derived from manual and station measurements as well as physical snow models. Specifically, the Airborne Snow Observatory (ASO) data sets use the iSnobal model in specific basins. This is a physically-based distributed snowmelt model and it accurately estimates the snowpack density by simulating the development and melting of the seasonal snowcover. It is calibrated and constrained using ground-based measurements of snow density near the target area. For more information, please navigate to https://data.nal.usda.gov/dataset/isnobal.

In areas where iSnobal has yet to be implemented, ASO relies on density measurements from NRCS SNOTEL and Snow Course observations and targeted manual density measurements conducted during each flight.

A: Machine learning and artificial intelligence methods, certainly show promise for developing predictive capacities in complex systems. One caution is that machine-learning methods, like simpler regression methods, cannot reliably extrapolate beyond the data set that was used to train them. Given the demonstrated lack of stationarity in the hydroclimatic system, it seems effective at this point to rely on the full-basin inventory techniques presented for operational water resource management. There are no doubt interesting scientific questions to be addressed using those techniques.

KNOW YOUR SNOW: UNDERSTANDING THE IMPORTANCE OF COLORADO’S SNOWPACK TO WATER AVAILABILITY IN THE AMERICAN WEST – April 2, 2019

Presentations were made by Colorado River District General Manager Andy Mueller, Colorado River District Deputy Chief Engineer Dave Kanzer and Center for Snow & Avalanche Studies Executive Director Jeff Derry topics included:

  • The importance of snowpack monitoring and snow science to water availability on Colorado’s Western Slope
  • Updates on current snowpack conditions
  • Threats posed to our water supply by dust on snow  

We received some great questions from participants that we, unfortunately, did not have time to discuss during the Q&A session. With this in mind, the River District’s team compiled those questions and worked to provide answers below. 

Please let us know if you have additional questions or would like more information on a specific subject.

With climate warming, we can expect “extremer” extremes. This a question still being investigated. One study predicts more extreme atmospheric rivers with a warming climate, but a reduction in the number of atmospheric rivers we receive. Here’s a link you might find helpful: https://climate.nasa.gov/news/2740/climate-change-may-lead-to-bigger-atmospheric-rivers/

A: A SNOTEL maximum ranking map shows the current status of a SNOTEL station in terms of comparing the current data value with that SNOTEL’s historical record for that day. A maximum ranking of 1 tells you for that day it is the most SWE ever observed at that station (or whatever time period in question). A ranking of 5 tells you it is the 5th most SWE observed at that station. These rankings are based on a specific sites period of record and for the time frame being referenced or compared against.

A: At the beginning of the river forecast season soil moisture was a bigger concern, it is still a bit of a mystery how it will unfold depending on spring conditions, as there are not many previous years in our history to compare an extremely dry year followed by an extremely wet year. But in areas that received a lot of snow, with just the sheer amount of snow we have seen, the runoff forecasts are above 100% for all basins in Colorado currently. Here’s a helpful link that includes soil moisture in the forecast model: https://www.cbrfc.noaa.gov/rmap/grid800/index.php?type=snow&area=cbrfc&year=2019&month=4&day=&hour=&type=soilsa

A: The CBRFC Webinar on April 4, 2019 indicated that many streamflow peaks are expected to be in the top 30% of their historical record, but at this point based upon average conditions, no points are expected to reach flood stage. However, spring weather and related melt will ultimately determine how this year plays out. A delayed melt and increase in snowpack into May and/or a quick warm-up could increase flood risk in certain areas. Stay tuned.

A: These points are based upon comparing seasonal high point at Mead versus seasonal low point at Powell; additionally the active volumes of these reservoirs are slightly different, leading to slightly different percentage numbers. Of course, reservoir levels change day-to-day, season-to-season and year-to-year based upon inflow and outflow rates.

A: Yes. It is a question of soil stability. Activities that decrease soil stability can lead to ‘fugitive’ dust. Some example activities include, but are not limited to, dry land farming, off-road vehicles, oil and gas operations, over grazing, etc. Dry conditions and drought can significantly influence stability as well. Typically, a moist winter in the Southwest means a reduced number of dust events and/or less severe dust events here in Colorado.

A: There are many federal, state and local entities involved in funding snow research. We are fortunate in Colorado to be blessed with a plethora of snow and hydro-climate researchers, most of which are based in Boulder CO. Federal funds come from US Dept of Commerce (e.g., NOAA), NASA, US Department of Agriculture (e.g., NRCS) and US Department of Interior (e.g., US Bureau of Reclamation) and others. In the State – the Colorado Water Conservation Board is very active. The Colorado River District helps to fund snow science as well (e.g., Center for Snow and Avalanche Studies).

WESTERN SLOPE WATER WEBINAR – August 29, 2018

Presentations were made by Colorado River District General Manager Andy Mueller and former External Affairs Manager Chris Treese and topics included:

  • Efforts to protect our water resources on the Western Slope
  • Current drought conditions throughout the Colorado River basin mean for western Colorado communities
  • Drought Contingency Planning (DCP) efforts that may help avoid the curtailment of Upper Basin water uses from Compact administration

Link to PowerPoint Presentation 

We received some great questions from participants that we, unfortunately, did not have time to discuss during the Q&A session. With this in mind, the River District’s team compiled those questions and worked to provide answers below. 

Please let us know if you have additional questions or would like more information on a specific subject.

A: Colorado’s constitution gives priority to municipal water demands over agriculture and industry. To your question, we are not aware of any current proposals of this kind. Of course, the River District would vigorously oppose any effort to upend Colorado’s system of prior appropriation or to take rights away from historical water users on the West Slope.

A: Importantly, we believe moving water from other (upstream) CRSP storage buckets to Lake Powell should be done before we are in a crisis. Additionally, we acknowledge this strategy is essentially a one-time shot in the arm for Lake Powell.

One of the variables with moving water from the Upper Basin CRSP reservoirs indeed concerns the amount of water they hold, and after any year that looks like 2018, that is a problem that accelerates consideration of demand management.

A: The advantage of potentially banking water in Lake Powell is that it is at the bottom of the system and could capture saved water from any of the Colorado River system basins in Colorado. That is not to say a reservoir in Colorado could not be a water bank vessel, but it would be a part of a water banking structure, not the final holding vessel due to the fact that water saved in the San Juan basin, for instance, could not be held by a reservoir in the northwest corner of the state. Lake Powell also has the inherent advantage of size. It is 25 times larger than Colorado’s largest reservoir. Without federal protections for conserved savings in Powell, however, other options – including the construction of new Compact storage in Colorado – could make sense.

A: That is a good question and it depends on the accounting of the water moved to Powell. The answer will affect exercise of the filling right against junior rights. Our presumption is water moved from CRSP reservoirs to Powell will remain and be accounted as system/CRSP water. Extended operations just “bends the curve.”

A: Sedimentation does present long-term risks for our ability to store water in Lake Powell. These risks, however, are less immediate than those presented by declining elevation levels resulting from long term drought and historic overuse by the Lower Basin.

A: The Bureau of Reclamation’s 24-Month Study is a good place to learn about water levels and projections. It can be found here: www.usbr.gov/uc/water/crsp/studies. This BOR website is also information-rich: www.usbr.gov/uc/water/index.html.

Yet another website that is very good with Lake Powell data is: http://lakepowell.water-data.com.

A: The Division of Water Resources is looking at waste no matter the priority of the water right.

This is an emerging priority of the DWR with apparent immediacy in Water Division 6 (Yampa, White, and North Platte basins). As you know, the Colorado Supreme Court’s Arkansas River Compact ruling of more than a decade ago has led to close scrutiny of waste in Division 2.

A: Thank you. It’s important that we keep end-users in mind as we approach these technical issues. As you saw in the webinar presentations, Colorado is projected to see continued population growth in the coming years. And how we grow will have tremendous impacts on both water quality and quantity in the Centennial State. The Colorado River District’s risk study found that a 10% increase in Upper Basin depletions could double the frequency that demand management efforts would be needed in order to meet our obligations to the Lower Basin states.

Everyone in the arid West plays a role in wise stewardship of our scarce water resources. We’ll need everyone’s efforts, large and small, to meet the twin challenge of increasing demands and diminishing supplies.

A: Under Colorado law, water rights are privately held and can be bought and sold on the open market. We do not advocate changing that system. For the record, the Colorado River District and the Middle Park Water Conservancy District both have adopted policies that prohibit providing contract water supplies to properties from which the water rights have been sold to TMDs. As for what a county government can do, Pueblo, Otero and Crowley Counties, for example, have adopted 1041 regulations that claim regulatory authority over the purchase of agricultural property and/or water rights where the underlying intent of the acquisition to transfer the water off the land. Additionally, Western Slope communities can incentivize the continued use of water on the Western Slope through zoning and conservation easements for land owners.

A: Good question. For communities on both sides of the Continental Divide, it’s important that we educate the public on our shared reliance on the limited water resources of the Colorado River. We all have skin in the game, and we all have a lot to lose – economically, environmentally and socially – under Compact curtailment scenarios.

A: In terms of directly influencing the recruitment of any business to Eastern Colorado, the answer is nothing. What the Amazon recruitment highlights is that the Front Range and all of Colorado will continue to grow, and we have to grow water-smart. That means more closely linking growth with water-use policies such as influencing outdoor irrigation/landscaping to be more appropriate to an arid climate. As Denver Water has advocated, growth needs to occur in more dense patterns where landscaping is minimized and infrastructure is in place.

A: On the Front Range and for that matter in places such as California, water generated by agricultural fallowing is a tool to create new supply for cities. In western Colorado, a water bank is not intended to supply new uses. It is intended either to proactively protect critical levels in Lake Powell to avoid Colorado River Compact non-compliance or to meet a compliance “call.” In other words, it is all about Lake Powell water levels. It is not anybody’s new water supply for growth. It is to protect existing water uses in Colorado.

A: The irony you point out is not lost on us – and others. Projects such as Windy Gap Firming have been in planning and permitted for a decade or more, before drought and low levels at Lake Powell prompted the concerns that exists today — and thus talk of demand management. In this timeframe, the Colorado River District has cautioned that Colorado’s allocation of water under the Colorado River Compact of 1922 and the Upper Colorado River Compact of 1948 could be nearing their limits. But under Colorado’s constitution, water development can proceed without regard to compact risks to either those proposing projects or others that will be affected by compact administration if it were to occur. The game changer, although it is not embodied in law, is Colorado’s Water Plan. In Chapter 8, the plan lays out seven principles – “the Conceptual Framework” — under which a transmountain diversion should be reviewed in order for it to gain state approval. http://cwcbweblink.state.co.us/WebLink/ElectronicFile.aspx?docid=199506&searchid=80d50cb3-95bf-405c-bfa5-587c633c7136&dbid=0

That said, the Colorado River District believes that current uses of water are at risk currently, absent any new development, under what appears to be the “new normal” hydrology of the Colorado River.

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