#Groundwater Issues

[wall-of-knowledge]

Problems caused by Excessive groundwater withdrawal

Table of Contents Key PointsDirect AnswerWhat Happens When We Take Too Much Groundwater?Real-World ExamplesUnexpected DetailComprehensive Analysis of Excessive Groundwater Withdrawal IssuesBackground and ImportanceDetailed Problems Caused by Excessive WithdrawalCase Studies: Ogallala Aquifer and IranComparative AnalysisMitigation Strategies and Future OutlookConclusionKey Citations Key…

[themorningnewsinformer]

Delhi's Water Crisis 2025: Causes, Impacts, and Solutions for Citizens

Introduction Delhi’s water crisis in 2025 has escalated to a critical level, affecting millions of residents. As water scarcity worsens, understanding the causes and solutions becomes essential for every citizen. Causes of the Water Crisis Over-Extraction of Groundwater The demand for water in Delhi outpaces the Delhi Jal Board’s (DJB) supply, pushing residents to rely heavily on groundwater…

[journosatyam]

bhakra-canal-dispute-between-haryana-and-punjab-complete-story

भाखड़ा नहर के पानी पर हरियाणा-पंजाब के उलझने की पूरी कहानी

गर्मी की शुरुआत हो और दिल्ली, पंजाब और हरियाणा में पानी को लेकर विवाद हो, ऐसा हो नहीं सकता. दिल्ली में जब आम आदमी पार्टी (AAP) सरकार थी, तब यह विवाद सुप्रीम कोर्ट तक पहुंच गया था. अब दिल्ली और हरियाणा दोनों जगहों पर भारतीय जनता पार्टी (BJP) की सरक���र है, दूसरी तरफ पंजाब में आम आदमी पार्टी की सरकार है. हरियाणा और दिल्ली में एक-दूसरे पर आरोप-प्रत्यारोप लगाने का दौर थमा तो पंजाब से नई जंग शुरू हो गई. भाखड़ा नहर के पानी पर विवाद इतना बढ़ा कि हरियाणा में सर्वदलीय बैठक तक बुलानी पड़ गई.

भाखड़ा ब्यास प्रबंधन बोर्ड की बैठक में हरियाणा और पंजाब सरकार के अधिकारियों के बीच में ऐसी झड़प हुई, जिसके बाद हंगामा ही बरप गया. दिल्ली में शुक्रवार को हरियाणा, पंजाब, राजस्थान और भाखड़ा ब्यास प्रबंधन बोर्ड की बैठक हुई लेकिन कोई राह नहीं निकल पाई. बैठक में तो यह सलाह दी गई कि हरियाणा को 8 दिनों तक के लिए अतिरिक्त 4500 क्सुयसेक पानी मुहैया करा जाए, भाखड़ा डैम से पंजाब पुलिसकर्मियों को हटा दिया जाए. सहमति तो नहीं बनी लेकिन इस पर सिसायत छिड़ गई है.

पूरा आर्टिकल पढ़ने के लिए यहां क्लिक करें👇

भाखड़ा नहर के पानी पर हरियाणा-पंजाब के उलझने की पूरी कहानी

[wausaupilotreview]

Wausau files federal lawsuit over PFAS contamination, citing long-term environmental and health risks

Greater Wausau Chamber CEO Eckmann is sharply critical of this effort. But Council President Rasmussen said, "I’d be far more concerned about what it says about Wausau if we make ratepayers absorb the cost...while letting polluters off the hook."

By Shereen Siewert | Wausau Pilot & Review Wausau in January initiated a comprehensive legal battle against multiple corporations doing business in the city to address PFAS contamination affecting its public water system, a move that is seeing mixed reaction in the community. The lawsuit, lodged in the United States District Court for the Western District of Wisconsin, targets companies like…

[aemiron-main]

watching the coal development moratorium get lifted in alberta & knowing that all of the water from the rockies to all of southern alberta is going to be completely fucked & toxic/filled with selenium (and we’ve already got issues with that & how it’s affecting the fish and bighorn populations) from coal-mining runoff & it’s going to cause absolute ecological disaster in this area and disaster for people re: safe water access & there’s ZERO new coal mining safety regulations in place (the only regulations are from 45 years ago and theyre barely anything/might as well not exist at all) and it’s just. A nightmare situation. The conservatives really are hellbent on fucking everything and everyone in this province over

[auroraborewellss]

Discover the crucial signs that indicate your borewell needs immediate cleaning in this informative SlideShare presentation. Learn about common issues like reduced water flow, foul smell, and sediment build-up that could compromise water quality. Ensure the longevity and efficiency of your borewell with these expert tips for timely maintenance.

[townpostin]

Water Crisis Sparks Protests in Adityapur's Srinath Global Village

Residents outraged over 8 lakh rupee water bill, demand action from builder and municipal corporation Severe water shortage highlights infrastructure challenges in rapidly growing urban areas. JAMSHEDPUR – Residents of Srinath Global Village in Ward 20 of Adityapur Municipal Corporation staged a protest on Sunday over ongoing water supply issues and exorbitant bills. The demonstration was…

[popp1n]

GHOSTING THE GOVERNMENT

|masterpost| ao3

Chap 1: A Not-so-Ghostly Getaway.

Pt 1

The diplomas, still crisp and smelling faintly of the school auditorium's mothball-esque stale air, lay forgotten in the storage pocket of the back seat. Outside, the oppressive silence of Amity Park clung to the humid night like a shroud. Under the sliver of a waning moon, three figures moved with struggling efficiency, their hushed whispers swallowed by the darkness, only interrupted by the thump and tumble of packing a small car's trunk full to the brim.

Sam wrestled a lumpy duffel bag into the cramped trunk of Jazz’s beat-up Corolla, its faded paint a familar reflection to the scuffed and chipped state of Amity Park's buildings and roads. Tucker carefully slid a disassembled and altered shortwave radio beneath a pile of old blankets, his knuckles pale as he adhered it to the floor with heavy-duty tape. In the driver's seat, Jazz checked the rearview mirror for the tenth time, her gaze flicking nervously towards the omnipresent, unblinking lenses mounted on nearly every lamppost, but most importantly those fastened to her childhood home.

This morning, Danny and his friends walked across that stage, officially free in the eyes of the State. Tonight, they were taking that freedom for themselves, one clandestine mile and issue at a time.

Sam finally managed to cram their luggage into place and successfully close the trunk without unnecessary noise. She slid into the backseat beside Tucker, who was checking the camera feeds again.

"The loop is still set, and I have my program ready to intercept feeds as we drive," Tucker sighed, lowering his computer screen and minimizing the glow, "All that's left is for Danny to finish and we can get out of here."

It was at that moment that they could hear keys jangling near the FentonWorks's front door. Danny made himself present and quickly hurried over to the open passenger side door.

The Corolla’s suspension groaned as Danny shoved a final ratty backpack crammed with scavenged ghost tech and blueprints onto the back seat, causing Sam to give a small indignant squawk at it landing in her lap before shoving it into place between her and Tucker. He slid into the passenger seat, closed the door, and buckled in a series of swift movements. Danny, ever the pragmatist, double-checked the rearview mirror, while Jazz gripped the steering wheel, knuckles white.

“Okay, everyone set?” Jazz’s voice was a low murmur, barely audible above the thrum of the engine.

Tucker huffed an affirmative, his gaze flicking to the other small, palm-sized device he’d carefully placed on the dashboard. It pulsed with a faint, stolen green light. “Just need to power that baby up once we’re a few miles out.”

Jazz reached over and squeezed Danny's arm. “Danny, are you sure about this? Leaving everything…” Her voice trailed off, the unspoken fear hanging heavy in the air.

“Positive,” Danny said, meeting her gaze. “Staying means… well, you know.” He glanced at Tucker, who offered a tight nod of agreement.

“So, portal us out of here then, speed demon,” Jazz said, a nervous edge to her usual teasing tone. “Last I checked, you could blink us to Gotham City before they even noticed we were gone.”

Danny sighed, running a hand through his already messy hair. “That’s the thing. I can’t.”

Jazz tilted her head to him, eyes on the road and confusion etched on her face. “What do you mean, you can’t?” She asked, her brow furrowed. “Are you… are you okay?”

“I’m fine,” Danny insisted. “Physically, anyway. But remember those ‘rural-urban wellness initiatives’ the government rolled out last year? The ones that supposedly monitored for earth quakes and groundwater?”

Jazz's eyes widened. “You think…?”

Tucker nodded grimly. “They weren’t just mapping out tremors and underground streams. They were mapping ectoplasm fluctuations...at least the sensors in town are. Every portal, even natural ones, creates a ripple. A pretty significant one, apparently.” He pointed towards the stolen and modified device on the dash. “This little beauty confirms it. They’ve got localized sensors all over Amity Park, calibrated specifically to detect any paranormal distortions. If Danny tried to portal us out now, it’ll be like setting off a silent alarm directly to GIW headquarters.”

A heavy silence descended upon the car. Jazz’s shoulders slumped slightly. “So, all those times they ‘randomly’ stopped by the house for ‘routine checks’ after you seemed a little… restless…”

Danny’s jaw tightened. “Yeah. They knew something. They’ve been watching. Waiting.” He sighed, "They probably wrote it off so far as interference from the lab portal and whatnot, but that isn't a foolproof defense."

Sam leaned forward in her seat. “This is the only way. Old-fashioned, on the ground, under the radar. Once we’re far enough out, past that massive ghost shield they're building, then maybe… maybe Danny can risk it. But not here. Not now.”

The weight of their words settled in the small car, replacing their initial surge of post-graduation hope with a stark dose of reality. It was a harsh reminder that their lives were nowhere close to normal. This was not a regular carpool to their shared college pick; although, it was no less emotional than the standard fair.

Tucker was excited for opportunities with the biggest technology conglomerate in the world. He and Danny managed to score scholarships along with paid internships with their practical demonstrations. Sam was interested in the gothic architecture and ecology courses that their destination had to offer. Danny was intrigued by the rumored curses around the city. Jazz was looking forward to finishing her psychology degree and potentially working in Arkham.

But home is home, no matter how strained it has become in recent years.

Emotions were complicated, and many a tear were shed by the teens as they pulled out of the neighborhood and headed towards city limits. Jazz offered each of them a blanket and bid them to rest.

Next>

[cathkaesque]

The local population in countries that export bananas typically eat different varieties grown primarily by small farmers. The ones for the Americans and the Europeans, Cavendish variety bananas, are grown in huge, monoculture plantations that are susceptible to disease. The banana industry consumes more agrichemicals than any other in the world, asides from cotton. Most plantations will spend more on pesticides than on wages. Pesticides are sprayed by plane, 85% of which does not land on the bananas and instead lands on the homes of workers in the surrounding area and seeps into the groundwater. The results are cancers, stillbirths, and dead rivers.

The supermarkets dominate the banana trade and force the price of bananas down. Plantations resolve this issue by intensifying and degrading working conditions. Banana workers will work for up to 14 hours a day in tropical heat, without overtime pay, for 6 days a week. Their wages will not cover their cost of housing, food, and education for their children. On most plantations independent trade unions are, of course, suppressed. Contracts are insecure, or workers are hired through intermediaries, and troublemakers are not invited back.

Who benefits most from this arrangement? The export value of bananas is worth $8bn - the retail value of these bananas is worth $25bn. Here's a breakdown of who gets what from the sale of banana in the EU.

On average, the banana workers get between 5 and 9% of the total value, while the retailers capture between 36 to 43% of the value. So if you got a bunch of bananas at Tesco (the majority of UK bananas come from Costa Rica) for 95p, 6.65p would go to the banana workers, and 38p would go to Tesco.

Furthermore, when it comes to calculating a country's GDP (the total sum of the value of economic activity going on in a country, which is used to measure how rich or poor a country is, how fast its economy is 'growing' and therefore how valuable their currency is on the world market, how valuable its government bonds, its claim on resources internationally…etc), the worker wages, production, export numbers count towards the country producing the banana, while retail, ripening, tariffs, and shipping & import will count towards the importing country. A country like Costa Rica will participate has to participate in this arrangement as it needs ‘hard’ (i.e. Western) currencies in order to import essential commodities on the world market.

So for the example above of a bunch of Costa Rican bananas sold in a UK supermarket, 20.7p will be added to Costa Rica’s GDP while 74.3p will be added to the UK’s GDP. Therefore, the consumption of a banana in the UK will add more to the UK’s wealth than growing it will to Costa Rica’s. The same holds for Bangladeshi t-shirts, iPhones assembled in China, chocolate made with cocoa from Ghana…it’s the heart of how the capitalism of the ‘developed’ economy functions. Never ending consumption to fuel the appearance of wealth, fuelled by the exploitation of both land and people in the global south.

[hope-for-the-planet]

From the article:

From Europe to North America, an energy revolution is breathing new life into empty, long-forgotten coal mine shafts — by repurposing them into places to store renewable energy. Using “gravity batteries,” these underground facilities aim to tackle one of renewable energy’s greatest challenges: storage. The method is simple: Excess renewable energy is used to power winches that lift heavy weights — such as containers filled with sand or rock — up the mine shaft. When additional energy is needed, these weights are released, generating power as they descend. This approach not only gives these disused mines a second life but also offers economic and environmental benefits to communities once reliant on coal. Hundreds of thousands of abandoned mines — about 550,000 in the U.S. alone — pose economic, environmental and safety risks. In some areas, these old shafts have caused collapses or polluted groundwater, while in others, the loss of mining jobs has hit local economies hard. Meanwhile, as renewable energy scales up, storage limitations become a pressing issue, especially with solar and wind, which are naturally intermittent. This year, solar is expected to surpass coal as a leading global power source, according to the International Energy Agency, highlighting the need for reliable storage to balance supply and demand. During the U.K.’s 2020 lockdown, for example, National Grid warned of potential blackouts when energy demand dropped by 20 percent, leading to excess renewable power that went unused.

Gravity batteries offer a straightforward but powerful — and cost-effective — way to address both of these problems at once. Their potential is already being realized. In Rudong, near Shanghai, the first commercial grid-scale gravity battery was connected to the grid in December 2023. Capable of storing up to 100 megawatt hours of energy, it can power nine homes for an entire year using only stored electricity. Across China, nine additional projects are in development, while in Switzerland, a commercial demonstration unit has been connected to the national grid for testing since 2019, showcasing the technology’s promise on a global scale. And now, other countries, from Finland to Australia, are getting on board.

[reasonsforhope]

Scientists have developed a new solar-powered system to convert saltwater into fresh drinking water which they say could help reduce dangerous the risk of waterborne diseases like cholera.

Via tests in rural communities, they showed that the process is more than 20% cheaper than traditional methods and can be deployed in rural locations around the globe.

Building on existing processes that convert saline groundwater to freshwater, the researchers from King’s College London, in collaboration with MIT and the Helmholtz Institute for Renewable Energy Systems, created a new system that produced consistent levels of water using solar power, and reported it in a paper published recently in Nature Water.

It works through a process called electrodialysis which separates the salt using a set of specialized membranes that channel salt ions into a stream of brine, leaving the water fresh and drinkable. By flexibly adjusting the voltage and the rate at which salt water flowed through the system, the researchers developed a system that adjusts to variable sunshine while not compromising on the amount of fresh drinking water produced.

Using data first gathered in the village of Chelleru near Hyderabad in India, and then recreating these conditions of the village in New Mexico, the team successfully converted up to 10 cubic meters, or several bathtubs worth of fresh drinking water. This was enough for 3,000 people a day with the process continuing to run regardless of variable solar power caused by cloud coverage and rain.

[Note: Not sure what metric they're using to calculate daily water needs here. Presumably this is drinking water only.]

Dr. Wei He from the Department of Engineering at King’s College London believes the new technology could bring massive benefits to rural communities, not only increasing the supply of drinking water but also bringing health benefits.

“By offering a cheap, eco-friendly alternative that can be operated off the grid, our technology enables communities to tap into alternative water sources (such as deep aquifers or saline water) to address water scarcity and contamination in traditional water supplies,” said He.

“This technology can expand water sources available to communities beyond traditional ones and by providing water from uncontaminated saline sources, may help combat water scarcity or unexpected emergencies when conventional water supplies are disrupted, for example like the recent cholera outbreaks in Zambia.”

In the global rural population, 1.6 billion people face water scarcity, many of whom are reliant on stressed reserves of groundwater lying beneath the Earth’s surface.

However, worldwide 56% of groundwater is saline and unsuitable for consumption. This issue is particularly prevalent in India, where 60% of the land harbors undrinkable saline water. Consequently, there is a pressing need for efficient desalination methods to create fresh drinking water cheaply, and at scale.

Traditional desalination technology has relied either on costly batteries in off-grid systems or a grid system to supply the energy necessary to remove salt from the water. In developing countries’ rural areas, however, grid infrastructure can be unreliable and is largely reliant on fossil fuels...

“By removing the need for a grid system entirely and cutting reliance on battery tech by 92%, our system can provide reliable access to safe drinking water, entirely emission-free, onsite, and at a discount of roughly 22% to the people who need it compared to traditional methods,” He said.

The system also has the potential to be used outside of developing areas, particularly in agriculture where climate change is leading to unstable reserves of fresh water for irrigation.

The team plans to scale up the availability of the technology across India through collaboration with local partners. Beyond this, a team from MIT also plans to create a start-up to commercialize and fund the technology.

“While the US and UK have more stable, diversified grids than most countries, they still rely on fossil fuels. By removing fossil fuels from the equation for energy-hungry sectors like agriculture, we can help accelerate the transition to Net Zero,” He said.

-via Good News Network, April 2, 2024

[mindblowingscience]

Chemical engineers at the University of British Columbia have developed a new treatment that traps and treats PFAS substances—widely known as "forever chemicals"—in a single, integrated system. The research appears in Nature Communications Engineering. Per- and polyfluoroalkyl substances (PFAS) are widely used in manufacturing consumer goods like waterproof clothing due to their resistance to heat, water and stains. However, they are also pollutants, often ending up in surface and groundwater worldwide, where they have been linked to cancer, liver damage and other health issues.

Continue Reading.

[technofeudalism]

‘this is going to get worse before it gets better’: panama canal pileup due to drought reaches 154 vessels

the panama canal, a key route for global trade, is facing a crisis. 154 ships are waiting, with an average wait time of 21 days. drought has reduced the water level in the main reservoir to critically low levels, which has resulted in the canal's locks struggling to function.

40% of all u.s. container traffic travels through the panama canal every year. the current situation is a direct result of climate change and overuse of natural resources.

climate change: weather patterns have shifted, and the area is receiving much less rain than it used to. the lake that feeds the canal is refilling at a much slower rate.

overuse: development around the area has increased reliance on groundwater and freshwater sources. shipping traffic has surged, flushing more water down the canal.

each ship requires about 200 million liters to pass through, amounting to 2.8 billion liters per day at just 14 trips.

at peak season, that's 10 billion liters per day, all of it fresh water flushed into the ocean. gone. wasted. unusable.

the low water level creates two main issues: availability and pressure. emergency water conservation measures are in place, restricting the biggest boats movements and slowing down the entire process.

this ultimately leads to inflation. shit is about to become even MORE expensive.

this isn't just a problem for some boats or the shipping business. it's a reminder of how our actions and the changing climate are impacting the world in real and tangible ways. the panama canal is a microcosm of a global issue.

we have failed to recognize the interconnectedness of our world and we are paying the price. it will not improve under capitalism.

[bonefall]

Ok, im back with more names. The bog was hard to find, so I’m basing it off of the area of Carrington Moss, which is in the area I think BB takes place if I’m reading the maps right

Also bc we’re talking about Shadowclan

Ok, so the names

First of all: Fen, Bog, Mire, and Peat, all names for this biome. There’s also marls, a rock found in the area

Again, I’ll only be using names I don’t remember being in the series (the obvious one being moss. It’s all moss)

Asphodel (bog asphodel), rosemary (bog rosemary), cranberry, cotton (cotton sedge), blackberry, bluebell, foxglove, iris, a plant called Mad-dog weed, also known as a water-plantain, admiral (red admiral), pipit (meadow pipit), partridge (gray partridge, but very rare) bullfinch, and bunting (reed bunting)

Close but you're a bit off-- Carrington Moss is, confusingly, an example of a moorland!

Specifically it is a lowland peat bog. Upland peat, lowland peat, blanket bog, dune heath, upland heath, lowland heath, maritime heath... all of these biomes are completely different, but all of them are referred to as moorlands.

Also, those names for the biome are not interchangeable. Those all have more specific meanings;

Fen: An alkaline wetland. Fed by fresh groundwater or runoff, these biomes are a lot richer in nutrients and the water is higher in oxygen. Because of this, they often have a much larger diversity of plant and animal species. Fens can sometimes become bogs over time.

Bog: An acidic wetland Thick moss, lots of dead matter, mostly a result of still water building up over many many years. Since the water is low in oxygen, you won't find many fish in these, and generally bogs are home to specialists who can handle the conditions.

Mire: Wet, muddy land that's hard to walk on Only synonymous with "bog" if you're using it in the informal sense of "being bogged down," not in the ecological sense-- a bog is a mire, but not all mires are bogs. You could have a mire made out of glue, tar, or caramel, if you were writing a really cool fantasy series.

Peat: A dark brown material formed from partially decayed plant matter. Essentially what happens when the top layer of moss or grass dies in a really wet place, is quickly grown-over by living plants, and then rots slowly underneath. A VERY important component of a bog, extremely useful as fuel.

For ShadowClan I'm actually modelling wetlands in and around Delamere Forest, specifically, because I ran into the issue you did of the British-English dialect having a lot of "overlap" in region names and scientific terms. If you want to go scouring for cool prefixes to suggest, you can check out Blakemere Moss, Black Lake, Mouldsworth Gap, and Abbots Moss.

Most of the plants you mentioned still grow here, though! Some other fun prefixes I've been thinking of though;

Lime (type of tree, no relation to citrus!)

Linden (another name for lime, which there are two types of)

Sphagnum (Important type of moss)

Snipe (type of bird that picks up its babies and flies away with them)

Coot (funny name bird)

Chaser (type of dragonfly)

Podzol (ashy soil found in places where plant decomposition is inhibited)

Quiver or Quake (Describing the movement of thick moss that has formed over the surface of stillwater, Q is a really rare letter in WC names)

Vetch (Common type of plant with a name I think is really cool)

Nymph (Baby dragonfly)

Skater, Skimmer, or Strider (Bug that hunts by gliding across the surface of water)

[rjzimmerman]

Excerpt from this story from The Revelator:

The water flowing from taps in Wilmington, North Carolina, looked clean, tasted normal, and gave no indication that it carried an invisible threat. For decades the Cape Fear River had provided drinking water to hundreds of thousands of residents in the region. But in 2017 tests revealed what many had feared: high levels of per- and polyfluoroalkyl substances (PFAS), chemicals linked to cancer, immune dysfunction, and reproductive issues, coursing through their water supply.

The contamination had been traced to Chemours, a spinoff of DuPont, which had been releasing PFAS chemicals from its Fayetteville Works plant for years.

The discovery sent shockwaves through the community, triggering lawsuits, emergency water-treatment plans, and a reckoning over how corporations and government regulators had failed to protect public health. But even as residents fought to hold polluters accountable, the company responsible for much of the contamination was tightening its grip on the agencies meant to regulate it.

A former DuPont and American Chemistry Council lobbyist, Nancy Beck, now holds a key position at the Environmental Protection Agency, shaping chemical safety policies that will determine how — or if — PFAS pollution is addressed. In the first days of the second Trump administration, the agency withdrew a proposed rule that would have imposed limits on PFAS discharges, a move that watchdog groups say amounts to giving polluters free rein to continue contaminating water supplies.

The crisis in Cape Fear and Bentham reveals the creeping, silent danger of PFAS, which has infiltrated groundwater, rivers, and drinking-water supplies across the world.

And yet, as the Trump administration accelerates its environmental rollbacks, the ability to regulate and mitigate this growing threat in the United States is being systematically dismantled.

“North Carolina is one area that I’m most familiar with where there’s an entire river system that serves hundreds of thousands of people [and] is very badly contaminated with PFAS,” Erik D. Olson, senior strategic director for health at the Natural Resources Defense Council, told The Revelator. “A lot of people are drinking that water every day.”

[ranticore]

the sea is a terrible place (or: here's some scary natural phenomena found in the sea of Siren)

The false reflection, mostly encountered by deep-diving phocids. This phenomenon occurs when ultra dense high saline water gathers in underwater brine pools on the sea floor. It appears reflective, like a mirror. Down in the deep, the only way you can see at all is to take some form of luminescence with you, which obscures the pool and shows you nothing but another phocid below, holding a light source. It's common for pelagic people to be unfamiliar with their own facial markings and reflection. They mistake the reflection as another phocid, or a ghostly apparition, and reach out. But the salinity of the brine pool is such that even touching it can scald the skin, especially as all mammals on siren are adapted to low salt conditions and require far far less salt than unaltered humans.

The abyss, of course. Most of the sea of Siren is not as deep on average as the sea on Earth. But there are cracks and trenches in the sea floor that go down, and down, and down... they are poorly explored (though the first settlers did send drones down) and sites of myth and legend for swimmers. The abyss is not usually dangerous, since it's easy to just not go down there, but sometimes the cracks seem to inhale and exhale - natural flows of groundwater, or attempts to fill a vacuum caused by a different crack releasing gas. So swimming over certain cracks might result in you being dragged down unexpectedly into the anoxic zone near the sea floor in the region... or it might result in you being unexpectedly shot up. These events are incredibly rare and usually passed off as tall tales, some selkie who claims to have flown due to being propelled into the sky

The snowstorm... an event that occurs when the sediment is agitated enough to completely white out the water. If the particles are the right size, echolocation clicks bounce back immediately, making sight and echo useless. Phocids and selkies trapped in the snowstorm could lose situational awareness and forget which way is up very easily, and the instant bounce-back of echo clicks is deeply unpleasant, giving the illusion of being 1 inch from swimming straight into a solid wall.

Shriekers. This is an issue where ice caps, glaciers etc meet the water. The ice cracks and breaks, and to sensitive phocid and selkie ears it's an unbearable shriek that can render them disoriented and deaf at long range, and break eardrums at close range. Around the ice wall, there's an almost constant background noise of screaming.

The false sky. A phenomenon that occurs when a swimmer loses situational awareness, and ends up diving deeper and deeper thinking that they're about to come up for air. The reduced gravity of siren means that it's more difficult under the water to feel gravity, resulting in a more weightless sensation than on Earth. Occasionally, a natural biolumescence in deep water may produce an illusion of the sky viewed through the turbid water, making the disoriented swimmers even more certain that they are travelling up, when really they are diving. In Spiral mythos this is treated as a specific type of mania.

The wanderer.. it looks like a phocid swimming in the distance. You hail them, click at them, wave your lantern, but they don't respond. If you get closer, they'll flee. This is a really common story among nearly all pelagic people worldwide, and what they are seeing are the vanishingly rare aquatic zeta, those who did not adapt to becoming terrestrial and became extremely solitary, so they were not able to regain language due to not having complex cultures and societies anymore. They resemble smaller, hairy phocids and are considered a type of (for lack of a better word?) fairy or trickster spirit in Spiral culture, a false friend leading you astray.

The flesh cloud. This is a mass of deceased scalefish, the hagfish-like animals which make up many of the fish shoals on Siren. If they enter an anoxic zone unexpectedly (if chased, pushed by currents, or just unlucky) they can die in large numbers, forming a tangled, decaying mass that drifts through the seas. These are heralds of rot and disease and the water around them is filthy and unclean, an infection risk for any swimmer with an open cut. Sometimes large nets are set up to catch and redirect them.

Sharp sand. Some substrate is made of silica and appears glittery, like fairy dust. When water mixes, these can form plumes which are hundreds of feet tall. They're not dangerous in and of themselves, but you had better make sure you close your eyes around it, no matter how pretty the dancing glitter might be. A common cause of corneal ulceration and abrasion.

Cherta's Tide. This is a big one. Tides are slow and rare most of the time, mixing the water and enabling life to flourish. But every so often, there are two different tides that come round, which can be predicted based on which moon is most prominent in the sky for the duration. Ishmael's Tide is a high water apocalyptic event, but there are many monitoring stations and contingencies to avoid it. Cherta's Tide (similar to a neap tide) is far more unpredictable and occurs irregularly, as the moon Cherta is smaller, darker, and harder to see. This tide is a low-water event. Vast stretches of the sea floor are laid bare and the underwater ridges suddenly become towering cliffs and barriers for people who can't fly. This can last for weeks at a time, and without the water of course most animal populations who can't hide in substrate take a huge hit. It can happen fast enough to strand a swimmer at the top of a ridge, nothing but air below all the way to what was once the sea floor, and they might be stranded, unreachable, and without food or water for a fatal period of time.