Mapping the meanders

‘Geological Investigation of the Alluvial Valley of the Lower Mississippi River’ is the prosaic title for this map so beautiful it could be art. Created by Harold Fisk for the US Army Corps of Engineers in 1944, it is one of 15 that charts the changing meanders of the great Mississippi river, each colour like a ghost trail of where the water once flowed.

Dawn skies are mirrored in the Blackwater Estuary, where river and sea meet and swirl around the tidal island of Northey.

HIS IS THE END, beautiful friend…I’ll never look into your eyes again…can you picture what will be, so limitless and free.’ Jim Morrison (of The Doors) could have been standing at the mouth of an estuary when he wrote those languidly poignant song lyrics. It is the end of a river, the death of a river, and yet there is freedom in what’s to come. That’s the ambiguity of estuaries.

The Blackwater in Essex is one such mouth. On the map it resembles jaws swallowing a couple of pills – the islands of Northey and Osea. They could be sea-sickness tablets because, let’s face it, the River Blackwater is going to need them. Here at the estuary, it mixes its freshwater blood with the salt of the sea. Brackish is the word, and without getting bogged down in the appropriately ambiguous definition of an estuary, let’s just agree it’s the hosepipe that tops up the sea.

Three things coagulate at an estuary and this is a perfect example: mud, water and sky combine to make one of the richest habitats on the planet. The river brings down sediments from its whole course, dropping them as it greets the sea. This mud, or salt marsh, or whatever form it takes, is rich in life. And where there is life, there is something to suck the life out – in this case the hundreds of thousands of wading birds that overwinter on the feeding grounds of this last true wilderness.

The sky is of course the deliverer of this spectacle. I would argue fiercely that an estuary is

TCOUNTRY WALKING no longer about the river or the water, but about the bird-bearing air above it. Let me show you. We’re on the seaward edge of the tidal island of Northey. A cold easterly makes our eyes water salty tears as we look into the desolate tract of mud, water and towering sky that is the Blackwater estuary. Clouds build, morph, then collapse, all in shades of black, white and grey. The sun is in the south west by now, rich and golden. Beams of light slant into the spiralling waves of twenty thousand lapwing, golden plover, knot and dunlin: an estuary full of birds. They are burning, burning with fear as a peregrine stoops from four thousand feet, down into forty thousand fleeing, whirling, panicking feet. Like the river, the peregrine’s course is true, inevitable, and ends in a death.

It’s the weight of that sky that makes an estuary seem melancholy. It’s also the sky that will evaporate droplets from the surface of the sea and start the whole process again. There is never an end for a river.

WALK HERE

Turn to Walk 7 in this issue for a route to the tidal island of Northey in the Blackwater estuary. You can also download routes at Dartmouth in Devon, Laugharne on the Taf Estuary in Carmarthenshire (beloved by poet Dylan Thomas), on The Wirral between the mouths of the Dee and the Mersey, and from North Queensferry to Aberdour on the Firth of Clyde at livefortheoutdoors.com/bonusroutes

Waterways have been a muse for many writers. The nature-writing classic, by JA Baker, was set among these wide estuary skies in Essex, and Roger Deakin dives into rivers – and moats, canals, lakes, and the sea – in his

Olivia Laing traced the Sussex Ouse from source to sea in weaving her journey with a narrative about Virginia Woolf who tragically drowned herself in the water at Rodmell. On a lighter note, Jerome K. Jerome wrote the hilarious

about a trip down the Thames, a river that also inspired the children’s classic by

Kenneth Grahame,

The Wind in the Willows.