#Colorado vulnerable to mudslides

Grand Mesa mudslide May 2014 via The Denver Post

Here’s a guest column from Paul Santi that’s running in The Denver Post. Here’s an excerpt:

The ingredients for deadly debris flows are steep mountain slopes, a loose mantle of soil and rocks covering the hillsides and choking the valleys, and occasional severe rainstorms. These things converge surprisingly often, and most canyons around here have an apron of both ancient and fairly recent debris flow deposits at their mouths, revealing a historic legacy of these events. However, the next ingredient is the kicker: wildfire. Suddenly, the tiny bit of stabilization offered by our patchy arid-climate vegetation is gone. On top of that, rainfall on burned areas runs off faster and in much greater volumes, since any sort of interception by plants or infiltration into the ground is drastically reduced. Oh, and by the way, the changing climate means that wildfires have been more frequent and larger, and intense rainstorms are more likely. More water, more tumbling rock and debris, and more danger.

That was the story in California last week, as the fire-flood-mud sequence played out once again. That has also been the story in Colorado many times in the past. In 2012, the Waldo Canyon Fire burned hillsides above Colorado Springs, and a rainstorm the next summer brought muddy debris down Highway 24 near Manitou Springs, tragically sweeping two people to their deaths. Post wildfire debris flows have destroyed houses and damaged roads and bridges above Boulder, Glenwood Springs, Durango, and many other Colorado cities over the last dozen years.

So what can we do about this? First, you need to know if you are personally in danger. The simple answer is that if you live near a canyon mouth, you live in risk from debris flows. If the forest above you burned, you are at even greater risk for the next few years, until the vegetation comes back. The same goes for highways crossing these areas. A more complex picture can be filled out with tools developed by the U.S. Geological Survey and others that predict that probability of debris flows, how big they will be, how much rain is needed to cause them, and where they will go. The USGS now routinely produces maps showing probability and volume for debris flows in areas where there were significant wildfires (over 80 of these maps were created in 2017 alone, including the Thomas Fire in Santa Barbara County that caused the maelstrom last week).

Second, and this is just as important, if you live near a canyon below a burned forest, evacuate when it rains, as even small storms can cause debris flows in this hair-trigger setting. Natural processes are highly variable and unpredictable, so warnings and evacuation orders have to be conservative — and this means that there will be false alarms. Don’t fall prey to “evacuation saturation” and ignore a warning because the last one didn’t pan out. It is heartbreaking to think of how many lives would have been saved in California last week had those families been somewhere else at the time.

Finally, we need to carefully consider where we are willing to build. Mountain canyons concentrate geologic hazards, and increase the likelihood of accidental fires. Therefore, the encroachment of our communities into steep forested terrain must be accompanied by planning and vigilance to protect ourselves. The scientific tools help, and they are getting better all the time, but our own awareness and caution can be life saving.

‘Atmospheric rivers’ aid the West — and imperil it — @HighCountryNews

From The High Country News (Emily Benson):

When a rainstorm slammed California’s Russian River watershed in December 2012, water rushed into Lake Mendocino, a reservoir north of San Francisco. The cause? An atmospheric river, a ribbon of moisture-laden air that can ferry water thousands of miles across the sky. When the tempest hit, the state was on the brink of an exceptional drought. But instead of storing the surge the storm brought for the dry days to come, the reservoir’s owner, the U.S. Army Corps of Engineers, let it run downstream.

They had to. Army Corps rules say Lake Mendocino must be partly drained during the winter, leaving room for the next deluge to prevent downstream flooding. But in 2013, that space ended up being superfluous, mostly because drought conditions kicked into high gear and the rainy season essentially ended after the December downpour. “We lost that water,” says Shirlee Zane, who serves on the board of the Sonoma County Water Agency, which delivers water from Lake Mendocino to nearby homes. The agency estimates that more than $2 million slipped down the river. It was a loss that might have been prevented if the Army Corps had known they could safely store the water — and one managers would hate to repeat. “We lose millions of dollars of water if we don’t have better forecasting,” Zane says.

Atmospheric river storms swelled the American River in January 2017, inundating a footbridge near Sacramento, California.
Dale Kolke / California Department of Water Resources

Now, scientists are getting closer to solving that problem. Atmospheric rivers can cause dangerous deluges — an atmospheric river contributed to the mudslides that recently killed more than a dozen people in southern California — but they also provide up to half the annual precipitation on the West Coast. To make the most of those benefits while reducing risks, researchers are improving forecasts using computer models, weather balloons and instruments dropped from airplanes. The knowledge they’re gaining could help reservoir managers stockpile more water for dry periods without sacrificing the safety of downstream communities. And as climate change intensifies both floods and shortages in the coming decades, meeting that balance will become even more critical.

“It’s possible to predict these storms, to a degree,” says Marty Ralph, the director of the Center for Western Weather and Water Extremes, part of U.C. San Diego’s Scripps Institution of Oceanography. Meteorologists can see an atmospheric river coming a few days in advance; and, just as important, they can also see when the coast is clear after a big storm swells reservoir storage. “With good enough forecasts of no big atmospheric river coming in the next few days,” Ralph says, “then it’s plausible that one could safely keep that extra water.”

To explore that possibility, Ralph and a group of scientists, water managers and agency officials are studying what would happen to water supply and flood risk at Lake Mendocino if reservoir operators didn’t always have to leave room for a winter storm that isn’t coming. Could they avoid a repeat of the December 2012 water dump, without imperiling people downstream? “It looks viable,” Ralph says.

Further improving forecasts could help. “We’re good at seeing (atmospheric rivers),” says Anna Wilson, also a researcher at the Center for Western Weather and Water Extremes. “But we are not yet good at telling exactly where they’re going to land, exactly how strong they’ll be, and, in certain instances, whether precipitation is going to fall as rain versus snow.” Wilson, Ralph and other partners, including a U.S. Air Force squadron nicknamed the “hurricane hunters,” plan to drop dozens of parachute-carried sensors measuring moisture, temperature and wind data through several atmospheric rivers early this year. Working with the National Weather Service, they hope to advance forecasts of storm location and other details.

Better forecasts could also help water managers deal with the increasingly intense atmospheric rivers climate change will likely cause. Because warmer air can hold more moisture, by the end of this century individual atmospheric rivers could drop substantially more precipitation on the West Coast than they already do, according to research done by Michael Warner, a Seattle-based meteorologist with the U.S. Army Corps of Engineers.

Those lessons won’t just apply to California reservoirs. For a place like Washington’s Howard Hanson Dam, more intense storms might demand faster reservoir releases, which could put downstream areas in peril. In addition to supplying Tacoma with water during the summer, the dam protects more than $6 billion in businesses, infrastructure and homes from flooding. “Every major flood in the coastal Pacific Northwest has been associated with an atmospheric river event,” Warner says.

Though it will take years of further research before official policies can be changed, managers at Lake Mendocino may try taking atmospheric river forecasts into account this year. This winter, for the first time, the steering committee of the Lake Mendocino project has requested that the Army Corps deviate from the rules that forced the agency to dump water in the past — if forecasts suggest it’s safe to do so. “We are in a feast or famine type of climate here on the West Coast,” says Zane, of the Sonoma County Water Agency. “If we have better data and we can do the forecasting … it’s going to improve our water management.”

This story was originally published at High Country News (http://hcn.org) on Jan. 11, 2018.

 

Rain totals from atmospheric river event in S. California January 8-9, 2018 via NWS Los Angeles.

Nederland budget approved

Mailboxes are laden with snow on April 17, 2016 in Nederland, Colorado. (Helen H. Richardson, The Denver Post)

From The Mountain Ear (John Scarffe):

A new Waste Water Treatment facility and sewer maintenance dominated the 2018, $4.9 million budget approved by the Nederland Board of Trustees during a regular meeting at 7 p.m., December 5, 2017, at the Nederland Community Center…

Estimated expenditures for each fund: General Fund: $2,793,371; Conservation Trust Fund: $16,000; Community Center Fund: $391,068; Water Fund: $708,808; Sewer Fund: $812,422; Downtown Development Authority Fund: $30,700; Downtown Development Authority TIF Fund: $2,900. Total: $4,755,269…

The Sewer fund capital improvements have multiple items such as manhole repairs, mains and a new vehicle. The design and engineering of the Waste Water Treatment Plant Biosolids project will get up to 100 percent in 2018 but will be reimbursed by a loan, Hogan said, and will hopefully be awarded a $950,000 grant for improvements. It is a $2 million project.

Capital improvements from the water fund include the other half of the new vehicle, a Micro Hydro Feasibility Study with a matching $8,000 grant, and other projects, Hogan said.

Grant activity includes a Colorado Department of Local Affairs grant for the Biosolids project, a Great Outdoors Colorado grant for Fishing is Fun; a Colorado Department of Public Health and Environment grant for Pursuing Excellence Raw Water Filtration, a Colorado Water Resources and Power Development Authority grant for the Micro Hydro Feasibility Study with an $8,000 match and a GOCO Parks grant with a $6,000 town match…

For the Water Fund, the changes in rates are explained in the fee schedule. Total revenue is $707,000, operating expenses are $475,000, capital improvements $91,000 and debt payments of $143,000, resulting in a net change in cash of negative $1,200.

The Sewer Fund will also contain a fee schedule increase. Total revenue is budgeted to be $814,000, operating expenditures $527,000, capital improvements $42,000 and debt payments of $244,000, resulting in a positive net change in cash of $2,000.

Hogan presented the 2018 Fee Schedule. Noteworthy increases include the water fee with a three percent increase, and the sewer fund with a four percent increase.

5 awareness tips on stormwater pollution

Barr Lake State Park photo via Colorado Parks and Wildlife.

From the University of Colorado at Boulder:

State and federal agencies task the office of Environmental Health and Safety at CU Boulder with ensuring everyone on campus does their part to keep our water clean by preventing chemical waste and other pollutants from being disposed of into storm drains and sanitary sewer lines.

As a large, eco-conscious community at CU Boulder, we have the great opportunity to become educated and work together to reduce our impact on stormwater. Small amounts of contaminants from all over the landscape add up to cause pollution in our water. It is important to remember even the little things matter. You will make a difference, no matter how small, if you can adopt simple habits and change the way you look at water quality.

A few important tips to keep in mind include:

  • Do not dispose of chemicals down the drain.
  • Report anything suspicious or unusual around stormwater.
  • Clean up after your pets, and do not litter.
  • Do not maintain or wash your car in public areas, where runoff will easily flow to storm water.
  • Be aware.
  • Evans: Riverside Park restoration update

    Evans Colorado September 2013 via TheDenverChannel.com

    From The Greeley Tribune (Tommy Wood):

    The beginning of the project was delayed because Evans kept the bidding for contractors open for a longer period than it planned, which pushed the project completion date to August 2018. The increased costs come from more complicated trash removal than contractors foresaw, and from increased wages for workers mandated by the Davis-Bacon Act. The project will cost $12.1 million, still under the $13.2 million budget.

    Riverside Park, 4000 Riverside Parkway, was destroyed in the 2013 floods when a berm protecting the park broke and inundated it under seven feet of water. The flood scattered debris all over the park and uncovered a landfill underneath Evans officials said they were unaware of. The park has been closed to the public since.

    Keith Meyer, the project manager for the restoration, said workers discovered asbestos in the trash that made cleanup riskier than they’d foreseen. It’s also heavier and denser than expected because it’s packed with dirt. Because Evans is paying for trash removal by the ton, that added $976,488 to trash removal costs.

    Additionally, Meyer said, Evans has to pay a total of $27,567 to workers to conform to the Davis-Bacon Act, which mandates public works laborers be paid the local prevailing wage — the hourly wage, usual benefits and overtime paid in the largest city in each county.

    The council will vote whether to accept the added costs in its next meeting, at 7 p.m. Jan. 2.

    After #Oroville, officials across the West review dam safety — @HighCountryNews

    New Oroville spillway finish work. Photo credit California DWR.

    Here’s an analysis from Emily Benson writing for The High Country News. Click through and read the whole thing. Here’s an excerpt:

    To avoid the risk of further erosion, however, both spillways [at Oroville] needed to be patched up before this winter. By early November, following months of ‘round-the-clock work, the California Department of Water Resources announced that Oroville was ready for the rainy season, though final repairs will take another year. And the consequences of the incident could last far longer: Its sheer scale means it has the potential to affect legislation and policy, as did earlier disasters at other dams. Safety officials in California and across the West are already reassessing spillways, updating disaster plans and refining evacuation maps, hoping to prevent a repeat of Oroville — or worse.

    Structural failures were the immediate cause of the Oroville catastrophe. The main spillway has successfully handled larger flows than what it saw last February. While it’s not yet clear exactly why it broke apart, some researchers say part of the blame lies in poor design and shoddy maintenance — and that those problems could have been addressed. An independent group of dam experts is investigating what went wrong, with a final report expected by the end of 2017. An interim report released in September notes that there was preexisting damage and repairs at the area that first crumbled. Weaknesses there could have allowed water to get beneath the spillway, potentially blasting apart the concrete from below.

    Administrative failures — problems with inspections or regulations — may share the blame for what happened at Oroville. A patchwork of agencies meant to prevent such problems regulates dam safety in the United States. Federal agencies like the Bureau of Reclamation and the Army Corps of Engineers oversee inspection and maintenance at their own dams. Dams that belong to the state, like Oroville, or a utility company or other non-federal entity, are typically under the jurisdiction of a state agency; the Federal Energy Regulatory Commission (FERC) is also involved in dam inspections at non-federal dams with hydropower projects they license, including Oroville…

    In Colorado, Oroville confirmed that dam safety officials were already on the right track, says Bill McCormick, the chief of dam safety at Colorado Division of Water Resources. There, the big test came in 2013, when widespread flooding in north-central Colorado driven by torrential rain led to the failure of about a dozen small dams. Nobody was hurt or killed as a result of the failures, “but they did get people’s attention,” McCormick says. (Several people died elsewhere during the flooding.) Another wet season in the spring of 2015 made clear the need to plan for different levels of flooding and dam releases. “Our main lesson from Oroville is that we still need to be vigilant,” he says, “but we’re doing the right things.”

    Cities explore the future of urban #stormwater — University of Denver Water Law Review

    From the University of Denver Water Law Review (Alicia Garcia):

    Need for a New System
    Chicago has the largest wastewater capture quarry, water treatment facility, and water treatment plant in the world. However, Chicago still continues to experience significant flooding from stormwater runoff. In the past five years, there have been approximately 181,000 claims totaling over $753 million in flood-related property damage.

    Brenna Berman, Chicago’s chief information officer, says that the city is, “still getting the same amount of rain annually that we got [in the past] but it’s coming at a different rate than it once did. However, we’re getting rain more quickly, rain for a shorter period of time, most likely due to global warming.” Therefore, the same solution does not work the same in every location.

    A Greener Solution?
    In response, Chicago has been installing green infrastructure to hold and treat stormwater. Currently, Chicago is in the midst of a five-year, $50-million plan towards creating ten million gallons of stormwater storage in hopes of reducing stormwater runoff by up to 250 million gallons per year. Permeable pavement has been installed in bike lanes and alleys, which allows for water to be soaked into the ground rather than flowing into the sewer system. Additionally, there are bioswales, tree pits, and infiltration planters, which are areas of vegetation and soil collecting and filtering stormwater that prevent flooding and allow cleaner water to enter the sewer system. Although there are a number of green infrastructure solutions available, there is not much data available regarding which types work best and how well they are working. That’s where City Digital comes in.

    City Digital, a partnership of companies based at University of Illinois’ UI LABS, heads the pilot project which combines sensors and cloud computing as an innovative solution to stormwater runoff. The project aims to develop the next generation of sensing and monitoring tools for green stormwater infrastructure. The partnership is comprised of large, multinational companies including Microsoft, ComEd, Siemens, Accenture, Tyco, and HBK Engineering, as well as academic institutions such as the University of Illinois, Illinois Institute of Technology, Northwestern University, and Argonne National Laboratory.

    These companies, universities, and the City of Chicago are collaborating together to identify and solve large-scale infrastructure challenges in order to develop solutions that can be broadly commercialized.

    How it Works
    Beginning in August of 2016, City Digital has been installing low cost sensors and innovative software tools throughout the city in order to monitor and evaluate the city’s current green infrastructure.

    The ultimate goal of this smart green infrastructure monitoring is to create a system of sensors that combines weather information with surface and groundwater monitoring to evaluate the amount of water present, whether or not it is entering the green infrastructure, and what the water undergoes once it enters the infrastructure. Additionally, the system will measure the pH levels and the temperature of the water. Above the ground, the sensors work to monitor the weather conditions, such as precipitation amounts and air pressure levels. Below ground, the sensors monitor soil moisture, chemical absorption rates, and water quality to determine if the infrastructure is managing the water as intended.

    The data collected by the sensors is then communicated via cellular network into an analytics platform. There, the effectiveness of the various green-infrastructures can be monitored in real time. As of this past spring, there are six sites throughout Chicago that are transmitting more than 20,000 streams of real time data that translate into site specific recommendations for green infrastructure being built in the future.

    Ultimately, the purpose is not only to determine if the green-infrastructure is working, but where and when certain types of green infrastructure are most effective. Specifically, whether the green infrastructure is preventing rainwater from entering the sewer system and what green designs work best for different types of rain and lengths of the storm.

    Supporters of the pilot project urge that smart green infrastructure monitoring can be a low-cost alternative to traditional monitoring. Joshua Peschel, one of the key players of the Chicago pilot project says, “the traditional way of monitoring stormwater infrastructure, if done at all, is with expensive measurements that are often very sparse in space and time. This project seeks to fill the data gaps by adding unique measurement techniques and intelligence to these new green streets in Chicago.”

    By providing innovative, low cost monitoring for green infrastructure, the pilot project is changing the way not only Chicago, but cities all over the world address stormwater issues. The pilot project is designed to create a pathway to commercialization so that successful pilots can easily and directly be extended throughout other areas of Chicago and even further to other cities both nationally and globally.