Out in the mountain ranges west of Canberra, the rivers are running full and the clouds hang low over the ridges.
ACT parks manager Brett McNamara stands on the access road amongst the ranges, in the valley below Mount Gingera and listens to the river run and the frogs croak.
"That is the sound of the city living," he says.
Canberra's park rangers are concerned legal protections given by the NSW government to a nearby, 6000-strong feral horse population across the border will eventually lead to the destruction of water catchments in Namadgi National Park.
These catchments are the whole reason Canberra was chosen to sit where it does, guaranteeing the capital a constant, clean drinking water supply.
McNamara explains this as he sits to drink from the Snowy Creek, using cupped hands to drink crystal clear water. The water will flow east to the Cotter, through the ridges, treated at a station near Casuarina Sands before coming out of some Canberran's tap.
Under the flowering alpine shrub by the creek is sphagnum moss, which has a texture like a sponge. McNamara tears out a small handful and squeezes out clear water; it acts as a natural filter and can hold water for years.
It's this same moss that houses the critically endangered yellow-and-black corroboree frog; the same moss that cleans Canberra's drinking water, meaning pumps don't have to work as hard.
It's also the same moss that wild horses — brumbies — south in the Kosciuszko National Park love to eat. The hard-hoofed animals wreck river beds and plants as they get to it and other flora, shredding a delicate alpine environment that never evolved to handle them.
Brumbies in Kosciuszko National Park were given protections by the NSW government in June. McNamara is concerned, the ACT's environment minister Mick Gentleman was amazed it even passed and environmentalists are angry.
The laws were spearheaded by NSW deputy premier John Barilaro, a Nationals member for the seat of Monaro to Canberra's east, overseeing an electorate that includes Queanbeyan and Kosciuszko.
It flies in the face of reason: scientists have repeatedly told the NSW government how destructive the animals are.
The whole reason Canberra is where it is, McNamara says, is because of these mountain ranges.
Brumbies have established themselves across the border and, left to roam free by laws protecting them in NSW, they will eventually come into ACT.
They would tear up valleys like the one where McNamara stands, polluting the water, driving up the cost of treating it and limiting the water resources future Canberrans had as Australia becomes hotter and drier.
"[Water] is just a commodity we take for granted," McNamara says.
Weather travels east across Australia, hitting the ranges of the Namadgi National Park, turning into clouds and dumping water in the ranges, which filter it as it flows east into Canberra's water catchments.
This is what Charles Scrivener, Australia's first surveyor, saw when he was looking for a spot to establish the Australian Capital Territory in 1913.
"The reason the ACT is shaped the way it's shaped is because of water catchments," McNamara says.
After the territory was established, one of the first pieces of legislation federal parliament passed were laws protecting the Cotter River and her water catchments.
That meant brumbies, which were well established in what would one day be Namadgi National Park, had to be driven out, corralled or killed. It was one of the ACT park ranger's first jobs.
McNamara says today rangers are always working to remove brumbies, kill wild pigs or stop hoons dumping cars and setting them alight inside the parks.
"What we do as park rangers is manage that human hand."
Horses are not native to Australia. They were first introduced to the alpine region in the 1800s and before long there was a feral population.
The laws protecting the Cotter catchments from pollution apply only in the ACT, which means the ridge lines straddling the western border have ruins of old homes built on one side of the ridge and out houses and kitchens built on the other.
People were not allowed to have any sewage or wastewater flowing into the Cotter, so it had to be piped out along the western-facing, NSW-side of the ridges.
Earlier, standing on Mount Ginini, McNamara looked south to see a small body of water just on the horizon; it's Tantangera, NSW, where a brumby population estimated to be in its thousands has established itself.
When brumbies start living in the ACT, they will be coming from Tantangera. There are no fences along the borders stopping them.
Members of the Save Kosci protest, a group lobbying for the NSW government to repeal the laws protecting brumbies, have shown The Canberra Times pictures of the damage horses have done there.
Healthy creeks are surrounded by tussock, lined in moss, shrubs and run clear water. The land horses had damaged was muddy, clear of moss and shrub, resembling a paddock or the backyard of a student share house.
Earlier in December, in the Kosciuszko National Park, where the mountains still hold patches of snow, helicopter pilot Colin de Pagter flew over the ranges to find horses.
His chopper startled a small group of brumbies — a stallion, a mare and a gangly foal — and they fled from the drum of the rotor blades.
"Just three ridges over from here is Thredbo," de Pagter said.
Kosciuszko Park's brumby population is estimated to be about 6000, maybe closer to 7000, and scientists have previously said the population would have to be reduced to 600 to save the Snowy Mountains.
De Pagter, the chief pilot for the Jindabyne based HeliSurveys, does surveying work for the NSW and ACT government as well as other organisations.
He said he risked losing business with the NSW government for speaking out but said he had a gutful of the lack of action on removing brumbies from Kosciuszko.
Their effects can already be seen in sections of the park mostly accessed by the public: trampled patches by the creeks, horse manure on the paths.
The ecosystem in the park is so delicate, visitors are asked to not answer nature's call near the glacial lakes in case the nutrients in their waste irreparably pollute the water.
In the park's south, De Pagter landed his helicopter where the CoWombat Track crossed the NSW and Victorian border.
The clearing was a picture of Namadgi's bleak future under brumby control. It was muddy, the creek and the nearby Murray River were in tatters, running at barely a gurgle and the water was dirty and thick in parts with green algae.
But in that same clearing four horse-proof, fenced-off sections had thick tussock growing to knee height, but still some horses had managed to get their heads through the wire to eat at outer edges.
McNamara warns once the brumbies are in the Namadgi, ranger resources will have to be constantly diverted to remove horses and reduce the damage they cause.
Environment minister Gentleman has made it clear the ACT will not follow NSW. Brumbies that cross the border will be shot or removed.
While some may be swayed by the romanticism around wild horses, Mr Gentleman says Canberrans know what is at stake.
"I believe Canberrans are quite critically aware of the danger and the importance of managing our environmental areas, particularly the pristine area of the Namadgi," he says.
The same laws protecting Canberra's water supply and keeping it clean mean the capital's rangers are obligated to remove brumbies.
McNamara says the romanticism around brumbies used to justify the new protections is a recent invention.
Back in the 1913, a Sydney Morning Herald article refers to the "scourge" of the brumby, a few decades after Banjo Paterson's famous poem.
At one point, according to the now defunct paper The Sun, in the 1940s brumbies were such a menace and attitudes were so against them, farmers advocated for the use of machine guns to thin numbers.
But today, Canberrans don't have to travel to the Victorian border to get a glimpse of what hard-hoofed animals are already doing to Namadgi.
McNamara stops by the roadside in Namadgi to look at large dug out patches. Feral pigs had sniffed out some roots they liked and shredded the ground to find them.
Damage like that destroys ground cover that holds the earth together and without it, when it rains, the water carries the loose topsoil into the rivers.
McNamara says the damage horses can do won't happen overnight, it would be generational. But he predicts strong signs could be seen as early as 2025 or 2030.
One day, Namadgi's wild valleys would look like horse paddocks, the water would be choked with mud and algae, the horses would be starving, the frogs would be extinct, Canberra's water catchments would be struggling and the whole reason Australia's capital sits where it does would be in ruins because of wild horses.