Parkway Trail Patrol, Long Overdue and Much Welcomed

From Sacramento County:

“American River Parkway Bike Patrol Hits the Trails

“Article Date: Thursday, August 6, 2020

“This past February, the Sacramento County Board of Supervisors voted to authorize the establishment of the American River Bike Patrol to watch over the bike trails on the American River Parkway. The volunteer Bike Patrol, organized by the National Ski Patrol (NSP), has recruited and trained members and began patrolling the trails in July.

“The patrol’s 55 volunteer members were trained by the NSP in first-aid, CPR and basic bicycle repair. Regional Parks Rangers helped to train volunteers on expected trail etiquette. All volunteers are required to wear a volunteer bicycle patrol uniform, distinguishing themselves from regular users of the trail. NSP coordinates bicycle trail volunteer schedules with Regional Parks.

“We are excited for these volunteers to hit the trails to help teach trail users about trail safety and etiquette,” said Liz Bellas, Director of Regional Parks. “We have seen an increase in new trail users this year and these new users don’t always know proper trail etiquette, which can be dangerous for other trail users. The Bike Patrol members will be great educational resources.”

“We are delighted to be part of the Parkway team and our agenda focuses on safety; safe cycling, safe walking and family enjoyment on the trail,” said Jim Che​ng, Bike Patrol Representative.

“Members of the Bike Patrol will act as trail ambassadors providing directional advice, equipment assistance, safety insights and bike safety programs, assistance with events and first-aid services.

“Similar volunteer trail programs exist throughout the state, including the American River Parkway Equestrian Patrol, Fort Ord Friends, East Bay Regional Park District Volunteer Trail Safety Patrol, Oakland Bike Patrol, Santa Monica Mountains National Recreation Area Mountain Bike Patrol, Marin Open Space Bike Patrol, and Tahoe Bike Patrol.

“If you see one of the Bike Patrol members while out on our trails, make sure you wave and say hello as you pass! For more information on the bike patrol, visit their website. “

Retrieved August 6, 2020 from

Be Well Everyone!

Posted in Public Safety

Suing Over Parkway/River Pollution

Local groups could use this action, as reported by KCRA,  as a model to help protect the Parkway.

An excerpt.

“A nonprofit environmental group is suing Caltrans over a homeless camp that is on the department’s land.

“The Stewards of the Mokelumne River say that a piece of property near Turner Road and Highway 99 in San Joaquin County has not been properly secured by Caltrans and as a result, homeless have moved into the property.

“According to the suit filed in Sacramento federal court, human and animal feces, used feminine hygiene products and used condoms are among the materials now polluting the river. The Mokelumne River is one of the sources of drinking water for the city of Lodi.

“The group is asking for an injunction requiring Caltrans to clean up the site and to secure it so the homeless camp cannot pollute the river.”

Retrieved August 3, 2020 from

Be Well Everyone!

Posted in Environmentalism, Homelessness, Public Safety

Folsom Lake Marina

The lake is getting too low for boats to remain, have to pull out, as this story from KCRA reports.

An excerpt.

“The water level at Folsom Lake is dropping by nearly half a foot each day, and soon boaters who rent a slip at Folsom Lake Marina will have pull their boats out.

“Marina managers told the tenants they should plan on removing their boats from the water by around Aug. 16, which is when the lake is expected to sink to an elevation of 412 feet above sea level. Below that elevation, water at the marina’s slips becomes too shallow to dock boats.

“The docks will eventually come to rest on the lake bottom as water continues to be released from Folsom Dam for fish habitat, agriculture, power generation and drinking water supplies downstream.

“As of Monday morning, the lake was sitting at 422.33 feet above sea level, according to data from the California Department of Water Resources.

“Since the start of July, Folsom Lake has dropped 17.5 feet and in the last week dropped 3 feet alone.

“The marina warned all boaters to use caution on the lake as obstacles are becoming too numerous to mark.

“There is a 5 mph speed limit with 200 feet of the shoreline. The 5 mph speed limit will expand across the entire lake when the elevation drops below 400 feet. At the current rate, the lake will likely hit that level by mid-September.”

Retrieved August 3, 2020 from

Be Well Everyone!

Posted in Water

Driving Alone to Work the Fastest

This article from New Geography upends one of the classic arguments for using suburban rail.

An excerpt.

“The long, streaking commuter trains (suburban rail) carrying workers mostly into and out of downtown every day may give the impression of “rapid transit.” However, regardless of the top speeds they reach, the average suburban rail rider spends far more time traveling to work than those using other modesof getting to work (Figure 1). They spend far longer than the majority of commuters, who drive alone. Even in the New York combined statistical area (CSA), with the largest suburban rail network a majority drive to work. Outside New York, nearly 2/3rds or more drive alone than use transit in the six CSAs with the next largest networks (Figure 2).

“Suburban rail travel times are extraordinarily long. The average one-way commute is 71 minutes, nearly 20 minutes longer than the average transit commute. Suburban rail comes closest to matching average transit times in Philadelphia, where its riders spend about 11 minutes longer traveling each way. Suburban rail trips are 28 minutes longer in Washington-Baltimore and 25 minutes longer in Los Angeles (Figure 3).

“This is indicated by American Community Survey (ACS) commuting data for 2018. ACS asks for information on how people commute to work (Figure 4). The 2018 question (#31) was “How did this person usually get to work LAST WEEK?” with this clarification “If this person usually used more than one method of transportation during the trip, mark (X) the box of the one used for most of the distance. Question #31 asks: “How many minutes did it usually take this person to get from home to work LAST WEEK?”

“This article reviews work trip travel times for the “railroad” mode in the CSA’s with the seven largest networks in the United States (Note). The larger labor markets that comprise CSA’s are used because the railroad networks are not confined to the core metropolitan areas. The largest suburban rail network is in New York, which carried 460,000 daily one-way commuters on three systems (Long Island Rail Road, Metro-North Railroad and New Jersey Transit). The smallest network, in Los Angeles carried 30,000 one-way commuters daily (Figure 5).

“Comparing Suburban rail to All Transit Modes

“The seven CSAs also the largest number of transit commuters, as well and the largest transit systems. They include the transit “legacy” cities of New York, Chicago, Philadelphia, Boston, San Francisco and Washington, as well as Los Angeles. These CSAs have the most comprehensive transit systems in the nation. Yet, the average one-way commute time is more than two-thirds greater than that of driving alone (51.0 minutes on transit and 30.2 minutes driving alone).

“Comparing Suburban Rail to Driving Alone

“Commuter rail riders have one-way trips that average 2.3 times that of those who drive alone in the seven CSA’s. Suburban rail commutes in Philadelphia compare best to driving alone, at just more than double (30 minutes more). Suburban rail riders have average trips 2.5 times as long as driving alone in New York, Washington-Baltimore and Los Angeles (Figure 6). Assuming travel to work and back home, the average suburban rail commuter in New York commutes for 90 more minutes than the average solo driver. The difference is even greater in Washington-Baltimore (94 minutes) and Los Angeles (96 minutes).”

Retrieved August 1, 2020 from

Be Well Everyone.

Posted in Transportation

Outer Space

A wonderful article from Aeon Magazine reminding us that it truly is infinite.

An excerpt.

“Space, as they say, is big. In The Hitchhiker’s Guide to the Galaxy (1979), Douglas Adams elaborates: ‘You may think it’s a long way down the road to the chemist, but that’s just peanuts to space.’ It’s hard to convey in everyday terms the enormity of the cosmos when most of us have trouble even visualising the size of the Earth, much less the galaxy, or the vast expanses of intergalactic space. We often talk in terms of light-years – the distance light can travel in a year – as though the speed of light is somehow more intuitive than a number written in the trillions of kilometres. We give benchmarks in the same terms (it takes light 1.3 seconds to travel between the Earth and the Moon) but, in our everyday experience, light is instantaneous. We might as well talk about the height of a building in terms of stacking up atoms.

“Maybe, if we’re feeling more adventurous, we use analogies based on personal experience. The distance to the Moon is 32 million school buses! If you could drive there in one of those school buses, going at 60 miles per hour, it would take you 166 days! I’m not sure that helps.

“I wish I could say that astronomers have a better intuitive grasp of all this. We don’t. Brains don’t really work that way. So we cheat with numbers. We use longer yardsticks to talk about bigger spaces: kilometres, light-years, parsecs, kiloparsecs, megaparsecs, gigaparsecs. We get comfortable with exponents (1,000 is 103; 1 trillion is 1012) and think in logarithmic intervals, where each successive step is a new power of 10. At some point, distance stops being a straightforward concept entirely. Here in the Solar System, space and time are both more or less well-behaved, but when you have to deal with the cosmos as a whole, you have to factor in the fact that it refuses to sit still for its fitting.

“Space is expanding. It has been since the Big Bang, and it’s not stopping any time soon. If you look at a galaxy far, far away, not only do you have to factor in that the image you’re looking at is old, you have to account for the fact that it’s no longer where it was when you saw it. Let’s say you see a supernova go off, in a galaxy a billion light-years away. Did the supernova just go off, or did it go off a billion years ago? You can say the latter, because the light has been travelling to us for a billion years, but since there was no way to observe it back then, what does saying that it went off in the past even mean? And that billion-light-year-distant galaxy – how far away is it, really? Maybe a billion years ago it was a billion light-years away, but the Universe has been expanding all that time, so now it must be much farther. Which distance do we use?

“Even time is distorted by the stretching of space. We can watch the brightening and dimming of that exploding star, as the shockwave tears through it, and say it took about 100 days to fade away. But if we compare it with a supernova nearby, on average, we’ll see that the distant one takes a few days longer. From our perspective, it’s exploding in slow motion.

Even with the limitations of definition, we do our best to measure our space and quantify its farthest reaches. We have catalogued countless galaxies, some so distant that their light has taken almost the entire lifetime of the cosmos to reach us. We have searched our maps of the cosmos for some indication of an edge, or a centre, and found none. We have no reason to believe the cosmos doesn’t just go on forever, in every direction, without any significant change in content or structure. Our galaxy is a single grain of sand in a vast unbroken desert; zoom out far enough, and everything looks more or less the same.

“There is a limit, though. However powerful our telescopes, and however long we stare, we will never see anything farther away than the edge of the cosmic bubble we call our ‘observable universe’. This is an imaginary sphere, centred on us, and defined by the speed of light and the age of the cosmos. The radius of this bubble is the distance that a beam of light could cover if it travelled for the entire age of the Universe.

“If every time we look out into the cosmos, we’re looking into the past, it stands to reason that looking far enough away could mean looking at the time so far into the past, it’s the moment when the Universe first formed. That’s what defines our cosmic horizon. Put another way, anything beyond our cosmic horizon is so far away that even if a light beam left it at the very moment the Universe started, 13.8 billion years ago, the distance is so vast that the light beam hasn’t had time to reach us yet. There hasn’t been enough time.

“We have good reason to believe that in this apparently boundless universe, there are galaxies beyond the horizon, just as, when you stand on the ocean shore and see nothing but water, you have reason to believe there’s land out there eventually, beyond what you can see. If you jumped in a ship and sailed away, your horizon would move with you, and you would eventually see that land. Similarly, if you could take off in an interstellar rocket ship to another part of the cosmos, your horizon would still be centred on you, wherever you were. Unfortunately, limited as we are by the laws of physics and the constraints of our modes of travel, getting far enough from home to significantly change our field of view isn’t practical. But we can still make inferences about what might lie beyond it. And despite the cosmic horizon being as subjective a boundary as a horizon is on Earth, it has one very important difference.

“When we look out to the edge of the observable universe, what we see is something truly astounding. The most distant light is also the oldest; it’s the light from the Big Bang itself. The early universe, right after the first moments of creation, was hot and dense, everywhere, humming with vibrating plasma; right at the edge of our vision, we’re looking into the past so far that we literally see that glowing plasma. The inferno persisted for around 380,000 years before space expanded and cooled enough that light and particles could travel freely through it. When we look at the edge of the observable universe, we see the last smouldering embers of that hot dense phase. We see a cosmos that is still on fire.”

Retrieved July 31, 2020 from

Be well everyone!

Posted in Technology

The City Organic

A very interesting article about cities from Aeon Magazine.

An excerpt.

“The ancient city of Alexandria lies on a narrow strip of Mediterranean coast to the west of the Nile delta. To the south is Lake Mariout, which once hemmed in the city rather closely, but has been reduced over the past century as land has been reclaimed for agriculture and for Alexandria International Airport. In 1921, during the period of British rule, a new masterplan was put in place for the city. It was prepared by William H McLean, a Scot who had an urban planning career across the colonial Middle East: he was town engineer in Khartoum, and also prepared a masterplan for Jerusalem. In his vision for Alexandria, McLean plotted its expansion to east and west, convinced that any land reclaimed from Lake Mariout would be needed for farming rather than housing. The fact that the city now straggles along the coast rather than sprawling inland is partly a result of this plan.

“The other striking thing about the form of Alexandria is its two bays. The site of the city was, when Alexander the Great founded it in the 4th century BCE, one large bay with an island at its centre, called Pharos. In the 3rd century BCE, a road was built to the island. Over time, the Mediterranean has added to the original earthworks to such an extent that Pharos has become the head of a peninsula rather than an island. On each side of this peninsula are the two bays of Alexandria. Before the Nile was dammed in the 19th and 20th centuries, its annual flood dragged silt from the length of the river to the delta. Along the way, the silt deposited in the riverbanks and in the delta itself created some of the world’s most fertile soil. This process also expanded the delta into the sea each year, and the earth that was carried westwards by the waves of the Mediterranean to add to the land connecting Alexandria and Pharos was also part of this cycle. The watery land of the delta held such agricultural value because of this rich earth carried north by the river, and so the reason that the land around Lake Mariout was claimed for farming rather than urban growth is embedded in a complex set of land and water movements.

“The Alexandria that you see on a map or satellite image today thus bears the long marks of actions by humans and nonhumans, its form emerging from centuries of collaboration between sea, land, river and people. But this is not generally how we imagine urban spaces.

“The city is a lie that we tell ourselves. The crux of this lie is that we can separate human life from the environment, using concrete, glass, steel, maps, planning and infrastructure to forge a space apart. Disease, dirt, wild animals, wilderness, farmland and countryside are all imagined to be essentially outside, forbidden and excluded. This idea is maintained through the hiding of infrastructure, the zoning of space, the burying of rivers, the visualisation of new urban possibilities, even the stories we tell about cities. Whenever the outside pierces the city, the lie is exposed. When we see the environment reassert itself, the scales fall from our eyes.

“Of course, cities are physically identifiable sites that are often clearly separated from the space around them. They might be surrounded by walls that define their limits, or green belts in which building is prohibited or heavily controlled. Even when large suburban districts surround the city, these often have separate governance systems. Nonetheless, all cities depend on a much wider territory beyond these boundary markers. Some or all of the following need to be brought in from outside to support an urban centre: food, water, building materials (wood, stone etc), workers, traders and their goods, raw production materials (wool, cotton etc), energy (in the form of material to be consumed, such as oil or coal, or on cables connected to a production centre such as a power plant or wind farm). This is the case irrespective of whether the city concerned has a clear physical edge or not.

“Much debate about cities, at least in English-speaking cultures, reproduces the confrontations between Robert Moses and Jane Jacobs in the mid-20th century. Moses is portrayed as the archetypal planner, seeking to control New York’s urban scene through the built environment, pushing through highways in the face of opposition on the ground. Jacobs, meanwhile, is thought of as the champion of street life, arguing that ordinary people, given freedom to mingle in their daily lives, are best-placed to bring order to the city. This ongoing confrontation between top-down and bottom-up models of urbanism is central to contemporary urban thinking, but it leaves out the nonhuman. Both Jacobs and Moses view the city, fundamentally, as an entity made by people, the unfolding of a human vision. It is this underlying assumption that I wish to reconsider.

“This is not to say that all 20th-century urban thinkers have been blind to the nonhuman. The philosopher Henri Lefebvre distinguished between urban spaces and urbanisation as a process; he foresaw a time when the latter would shape all modes of life at a planetary scale. The architectural historian Sigfried Giedion and the urbanist Lewis Mumford similarly saw essentially urban technologies conquering space and time. The literary scholar Raymond Williams traced the cultural separation between city and countryside. But all of this work has not succeeded in shifting the popular idea of the urban as human space, with a nonhuman outside. In fact, by claiming that urban processes or technologies might expand to dominate the rest of the world, some of these thinkers reinforce an imagined historical distinction between the city and nature.

“Even when thinking of nonhuman experiences of urban space, it can be difficult to move beyond the idea that the city is, in essence, human. In 2016, David Attenborough used episode six of his BBC television series Planet Earth II to follow animals in Jodhpur, Rome, New York and Mumbai. Viewers were encouraged to think of how humans might shape these spaces to be more accommodating to multiple species living together. But in this representation, humanity remains the architect of the city; New York is described as being ‘the most unnatural place on Earth’. So in fact what emerges is a new version of the lie, with humanity as the dominant force in the creation of a complex, multispecies habitat.

“You might wonder why I describe this as a lie. Surely architects, planners, engineers and municipal authorities make our cities? If I am claiming that they don’t, then, you might say, am I trying to help humans duck the blame for the ecological impact of urbanisation? I will deal with the first question by analysing the lie more deeply, before returning to the second in the conclusion.”

Retrieved July 30, 2020 from

Be well everyone!


Posted in demographics, History

High Speed Trains

I have always loved the idea of these, but, as this article from the Antiplanner notes, our success in building and managing them is not good, especially in California.

An excerpt.

“The California Debacle

“As is well known, the California high-speed rail project is incomplete and out of money. The project got its start in 2008 when the California High-Speed Rail Authority, chaired by former state senator Quentin Kopp, persuaded voters to approve the sale of $9 billion worth of bonds to build the system, which was then projected to cost about $33 billion. Proponents claimed that private investors, the federal government, and others would come up with the rest of the funds. As a safeguard, no bonds could be sold unless they were matched by someone else.

“No private investors materialized, but California scored almost 40 percent of Obama’s high-speed rail funds. In a purely political move, one of the Obama grants came with a requirement that construction should commence in California’s Central Valley, where two Democratic congressmen were fighting close re-election campaigns. The federal grants plus some local government funding allowed the state to sell about $5 billion dollars worth of bonds, giving it $10 billion. Costs quickly rose above projections with the latest estimate being $80 billion. California’s governor has said he has no intention of spending any more state money and even Quentin Kopp has backed away from the project.

“The one Amtrak train connecting Los Angeles with the Bay Area still trundles along at an average speed of less than 39 miles per hour. Result: $4 billion federal dollars and at least another $6 billion state and local dollars wasted.

“The Northeast Corridor Money Pit

“The 2009 economic stimulus law gave Amtrak $683 million to improve service in the Boston-Washington corridor. On top of this, the administration gave Amtrak close to a billion dollars more for the corridor.

“Before spending this money, the fastest trains in the corridor took two hours and 46 minutes to go between New York and Washington and three-and-a-half hours to go between New York and Boston. Today, the fastest trains between New York and Washington take two hours and 49 minutes, a slowdown from 81.7 to 80.2 miles per hour. The fastest trains between New York and Boston still take just three-and-a-half hours, but there are fewer trains that are that fast.

“Amtrak did introduce one train a day that runs non-stop between New York and Washington in two hours and 33 minutes in one direction and two hours and 35 minutes in the other direction. That sounds like progress, except that in 1969 the Penn Central Railroad ran non-stop trains in that corridor that took two hours and 30 minutes.

“The real problem is that the Northeast Corridor has such a huge maintenance backlog that Amtrak, and the commuter railroads that use some of the tracks, need to spend $52 billion just to keep it running. Only after spending that much could any additional billions be expected to actually improve service. This makes the corridor little more than a giant money pit. Result: $954 million of high-speed rail funds wasted.

“Who Shot the Lincoln Trains?

“Before going to Washington, attorney Abraham Lincoln counted several railroads among his clients, and many years later the Alton Railroad operated a train between Chicago and St. Louis that it called the Abraham Lincoln. Today, Amtrak calls the four trains it runs on that route at an average of 53 miles per hour the “Lincoln Service.”

“The State of Illinois received $1.343 billion from the federal high-speed rail fund, plus $46 million in other federal funds, to speed up and increase frequencies in this corridor. The state spent much of this money double-tracking the line and improving grade crossings to allow trains to run at 110 miles per hour. This certainly benefitted Union Pacific, which owned the tracks and can now run more freight trains in the corridor.

“However, passengers haven’t yet seen any benefit. The Lincoln Service still has just four trains a day running an average of 53 miles per hour. Result: $1.389 billion wasted.

“The Pacific Northwest Tragedy

“The state of Washington received more than $800 million to speed up trains between Seattle and Portland. The state estimated that it could reduce the three-and-one-half hour journey by ten minutes, effectively increasing speeds from 53.4 to 56.1 miles per hour, which is still not anything close to high-speed rail. The state also promised to increase train frequencies.”

Retrieved July 29, 2020 from

Be well everyone!

Posted in Transportation

Lithium in Our Water

According to this article from the Sacramento Bee, this is a good thing.

An excerpt.

“An element commonly found in aircraft and some batteries is said to have an anti-suicidal effect when consumed via public drinking water, new research has found.

“A compilation of studies conducted between 1946 and 2018 show that areas with high concentrations of lithium in public drinking water had “correspondingly lower suicide rates,” according to a news release.

“Research that has touted this connection suggests the element — sometimes dubbed the “magic ion” — could be used to combat risks associated with mental health conditions, especially in communities that have a high prevalence of criminal behavior, chronic substance abuse and risk of suicide.

“The study was published Monday in The British Journal of Psychiatry.

“This study shows that the boundaries between medication and nutritional interventions are not as rigid as we used to think, opening up the possibility of new treatments that span both domains,” Dr. Carmine Pariante, a professor of biological psychiatry at the Institute of Psychiatry, Psychology and Neuroscience at the King’s College London, said in the news release.

“More knowledge of the beneficial properties of lithium and its role in regulating brain function can lead to a deeper understanding of mental illness and improve the well-being of patients with depression and other mental health problems.”


“Lithium is a naturally occurring element found in vegetables, grains, spices and rocks where it is weathered down into soils and thus into public drinking water, the researchers said.

“It’s also the lightest-known metal that is “so soft that it can be cut with a kitchen knife and so low in density that it floats on water,” according to LiveScience.

“What’s more, lithium is a mood stabilizer, the National Alliance on Mental Illness says. It’s widely used in medications for the treatment and prevention of bipolar disorder, which involves episodes of depression and mania.

“These health benefits have “been known for centuries,” the researchers said, and have ties to an ancient Native American medicinal spring famous for its lithium-enriched water and “health giving properties.”

“In fact, the popular soft drink 7-Up contained lithium when it was created in 1929,” according to the researchers.

“The team identified 415 studies that looked at the association between lithium concentrations in drinking water and suicide rates in 1,286 regions in Austria, Greece, Italy, Lithuania, Japan, the UK and the U.S., according to the paper.

“They then narrowed it down to 15 studies that demonstrated that “higher levels of trace lithium in drinking water may exert an anti-suicidal effect and have the potential to improve community mental health,” lead author of the study Dr. Anjum Memon, chair of epidemiology and public health medicine at the Brighton and Sussex Medical School, said in the release.

“Although the levels of lithium found in drinking water are “far lower” than those found in medicines, the duration of exposure to the element in water “may be far longer,” Dr. Allan Young, chair of mood disorders at King’s College London, said in the release.”

Retrieved July 29, 2020 from

Be well everyone!

Posted in History, Public Safety, Water

Water Supply Reliability

A review of this issue from the California Water Blog.

An excerpt.

“Water supply reliability is a major policy and management goal in California, and in the rest of the world, today and since the beginning of time.  The goals of reliable water supplies have grown from supporting human health, to supporting economic prosperity, to supporting healthy ecosystems, even when these goals conflict.

“Since ancient times, water supply planning, engineering, and operations have sought to provide reliable water supplies.  But until 106 years ago, there was little sophistication on exactly how reliable a water supply would be or should be.

“Today, water uses have grown and diversified, and sometimes conflict when water availability is insufficient for all uses.   Water availability will always be limited, despite infrastructure investments, and often will diminish or become more expensive with climate change and evolving environmental and public health standards.

“However, perfect reliability is never possible, and high reliability often incurs high economic or environmental costs.  This has long been the dilemma in California.  How do we balance reliability, the costs of improving reliability, and the water shortage costs of unreliability?

“Allen Hazen’s 1914 paper established a direction for solving this balancing problem.  His paper, “Storage to Be Provided in Impounding Reservoirs for Municipal Water Supply,” assembled streamflow data for more than a dozen water supplies and examined their reliability for a range of water use levels and a range of reservoir sizes.  These calculations were done by hand.

Realizing that these streamflow records were short, he further fit these reliability results onto “probability paper” (which he invented) to better estimate reliabilities for different extremes, configurations, and demands.

“For water wonks with technical or modeling interests, Hazen’s paper remains well worth reading.  Few papers about delivery reliability today thoughtfully synthesize such breadth and detail.  Some of the paper’s main lessons remain relevant for water policy and management:

  • No water supply can be completely reliable (from an engineer or manager’s perspective).
  • Higher reliability requires greater infrastructure costs, with extreme reliabilities incurring extremely large infrastructure and costs.
  • Seasonal and over-year water storage should be considered quite differently. Seasonal storage of water in reservoirs requires less storage capacity per unit of reliable delivery.  Storing water for over-year droughts requires proportionally more storage capacity and costs.  “With a larger reservoir, there is some further gain with increasing size, but in a diminishing ratio.”
  • High levels of reliable supply require larger reservoirs, which are costly and will often take years to refill.
  • Even an infinite reservoir size cannot reliably deliver more than a reservoir’s average annual inflow.
  • Regions with more variable hydrology require greater water storage capacity to supply the same reliability, all else being equal.
  • Climate change is likely, but is hard to estimate. There also seem to be longer-term cycles in runoff records, which are difficult to characterize and predict.
  • Quantifying water shortage amounts is important. Probability distributions of shortage can be more useful than the mere probability of a shortage.  However, probability distributions of shortages are harder to estimate, as shortages are usually rare events.
  • Water reliability analysis is inherently approximate, and it is not worthwhile to overly refine data. “In all hydraulic data the probable error of measurement is considerable. There is, therefore, no justification for the application of extreme refinements in methods of calculation.” Evaporation estimates and data are “less adequate than could be desired.  Nonetheless, some approximations can be reached.”  Longer flow records reduce uncertainty, but do not eliminate it.  Even averages have errors. However, probable errors in such estimates can be quantified.
  • The natural storage in lakes and sandy stream and lake banks can only be approximated, but can “have a great influence on the required storage, especially at relatively low draft [withdrawal] rates. …”.
  • Modeling with monthly flows and operations is somewhat less accurate than daily flows, and tends to under-predict storage needs for a given reliability and other conditions. Weekly time steps correct most of this underestimation.
  • Balancing the cost of improving supplies against shortage costs is needed. Reducing water use or adopting other water supplies can be less expensive than expanding reservoirs to increase water storage, especially for infrequent droughts.
  • Sometimes hedging reservoir releases, to create more frequent small shortages, can be less damaging overall than accumulating a smaller number of large shortages instead.
  • Public displeasure with large drought shortages can lead to infrastructure overinvestment. And the public seeing water spilling from full reservoirs in a few years can encourage the public to think that a supply is not being used to its reasonable limit.
  • Hazen extensively discussed limitations of his methods and findings, and estimated and discussed probable errors in his findings. As he summarized, “frank recognition of the large probable errors in many of the results cannot fail to be advantageous.”

“Much of today’s work on water supply reliability would advance to reflect some of the methods and thinking from 1914.”

Retrieved July 27, 2020 from

Be well everyone!

Posted in History, Technology, Water

31 Day Accurate Weather Forecasts

A dream you say, maybe not, according to this article from Scientific American.

An excerpt.

“Hey, Google, what’s the weather? We have become comfortable with the idea that we can make decisions based on accurate weather forecasts for the next three, five or seven days. Families plan cookouts for the upcoming weekend. Citrus farmers protect orange trees if a freeze is coming. Emergency managers evacuate towns that will be downwind of wildfires. Communities along rivers prepare sandbags to line homes and businesses if heavy rain looms.

“But all kinds of decisions could benefit from accurate prediction that stretched as far as three or four weeks out. Farmers could determine how safe it is to plant crops in early spring by finding out whether a late-season frost is expected. Ski-resort operators could choose to wait to start making snow if temperatures were likely to warm again before they could set a base. Water managers could draw down reservoirs in anticipation of spring flooding—or store water if drought were expected. And, of course, you could plan for what your vacation might be like next month.

“In the past several years atmospheric scientists have started to publish “subseasonal” weather forecasts that extend to three and four weeks. A typical seven- to 10-day outlook provides daily high and low temperatures, the percent chance of rain or snow, and wind conditions. A subseasonal projection predicts whether temperatures will be warmer or cooler than average for a given date, based on historical data, and whether it will be wetter or drier than normal. It also foretells hazardous and extreme weather. This time frame fills a big gap between short-term weather reports and seasonal forecasts that anticipate broad trends such as whether El Niño conditions in the Pacific Ocean will bring a warm summer to North America.

“Subseasonal forecasts are improving. For example, a set of weather models known as SubX (the Subseasonal Experiment), led by me at George Mason University and one of my colleagues at the University of Miami, accurately predicted several weeks in advance the increased rainfall associated with Hurricane Michael in 2018, a bitterly cold air outbreak in the Midwestern U.S. in late January 2019, and the July 2019 heat wave in Alaska. The SubX project, begun three years ago, combines forecasts from seven major climate and earth research centers in the U.S. and Canada.

“As an exercise for this article, on February 27 I used SubX to create forecast maps for the U.S. and for the world for March 21 through March 27—a time span 23 to 29 days out. The maps predicted warmer-than-normal temperatures in the Eastern U.S. and colder-than-normal temperatures in the West. They indicated that early spring conditions would prevail along the East Coast and that prolonged winter would persist in the West. The Southeast would continue to be wetter than usual, following a wet February. Several of the predictions were spot-on. A couple were not.


“The seven- to 10-day weather projections we depend on are based on computer models that simulate how the atmosphere evolves. They contain mathematical equations that estimate how temperature, winds and moisture will change second by second and day to day. Since the birth of weather models in the 1950s, forecasts have steadily improved thanks to better scientific understanding of these variables and to advances in computing power. In 1990 only three-day forecasts were 80 percent accurate or better. Today the three-, five- and seven-day outlooks are at that level.

“Many more factors must be considered in a week 3–4 forecast. Like a seven-day projection, this exercise begins with the current weather. Every day large national meteorological and space agencies around the world, including the National Oceanic and Atmospheric Administration and NASA, provide about four million observations of air temperature, atmospheric pressure, winds and humidity from weather balloons, weather stations, airplanes and satellites. Atmospheric scientists combine all these data in a weather model.”

Retrieved July 24, 2020 from

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