The reach of water [downstream from here] commences with the Maple-Durham Lock pool, in my opinion, far the best of the whole river Thames.
This pool, which forms no part of a back or mill stream, and over which, previous to the canalisation by means of locks, the Queen's highway must necessarily have run, is now claimed exclusively by Michael Blunt, Esq., of Mapledurham House, as his own private fishery.
This claim on the part of the public, I most utterly and entirely deny; but, should a stranger row his boat within the charmed precinct, and attempt to fish, Shepheard, the lockman, will at once put off from the Round House, and continue to row and splash about him.
In this Shepheard only does what he is paid to do; but how, for this last twenty years, he has escaped with a whole skin and a dry shirt, is a mystery beyond the powers of my solution.
From the mouth of this pool down to the tail of the eyot opposite the Roebuck Inn, is first-class water for large trout, jack, chub, and perch; but the right of netting it is leased by Mr. Blunt to the above-named Shepheard, and is exercised by him very freely. This does not, however, stop its being good angling water, for the stream being very rapid, and running over gravel, with occasional 'aids', causes the fish from the lower deep to constantly stive up, while it renders at the same time the process of netting anything but easy.

1867-: Lock Rebuilt?
1873: Taunt's Map and Guide to the Thames -

The Lock also, in combination with the Weir, is well worth notice, presenting at every turn a varied arrangement, each variation as lovely as the last.
Mapledurham is essentially a "Painter's Paradise".

1881: George Leslie, "Our River" -

The lock is picturesque, with a nice old lock-keeper.  But this pretty corner of the river is dreadfully marred by an ugly little iron bridge for the tow-path;  if it had only been of wood, no harm would have been done.  It is very hard that this place, of all others, should have been singled out for the display of improved modern construction
Just above the lock, a friendly row of trees casts an agreeable shade across the river and tow-path;  here a small island is reached, a favourite resting-place for camping parties. 
The attractions of Maple Durham also induce possessors of house-boats to anchor there.  I am glad to say, they generally have the taste to moor above the lock, so as not to interfere with the beauty of the scene below.  In all my river experiences I have never tried one of these boats, but they have their charms, no doubt, and much fine, independent pleasure may be got out of them.  They look inviting and snug with their little windows and curtains, their bird cages and pots of flowers, the smoke curling up from the kitchen chimney and the cooking and washing up going on inside;  but I cannot help thinking it must be a little tedious, and I have observed, that if not employed on some active business, such as cleaning or cooking, the occupants very often wear rather a blasé expression.
Of course there are house-boats and house-boats.  Some of the great saloon barges, varnished and gilt, and furnished with profuse magnificence, refrigerators, pianos, &c., with kitchen in a separate boat and a host of attendant servants, appear sadly out of place on the river, and make one suspect that the proprietors are gentleman with a penchant for yachting, but deterred from the marine indulgence of their hobby by dread of sea-sickness.  In a moderate-sized house-boat an artist or any one fond of the river ought to be pretty happy, especially if he is not above doing a lot of things for himself, as it is precisely the novelty of such work which gives the whole charm to this mode of life;  and in any case house-boats are in no sense open to the objections of the steam launch.

1882:  Wm Sheppard retired after 54 years service.  Dean Church wrote of him:

He was the most inveterate destroyer of fish that the Thames has ever known.  He rented the right of netting, and skinned the river relentlessly.  With his bag-nets and flue-nets, and other diabolical contrivances of misplaced ingenuity, he cleared the river of everything that was much above the size of a sprat.  He would sometimes send as much as half-a-ton of fish to Leaden Hall Market.

[ So much for the "nice old lock keeper"! ]

William Morris 'News from Nowhere" (in a future rural utopia) -

We were at the lock in a very little time; and as we lay rising and rising on the in-coming water, I could not help wondering that my old friend the pound-lock, and that of the very simplest and most rural kind, should hold its place there; so I said:
I have been wondering, as we passed lock after lock, that you people, so prosperous as you are, and especially since you are so anxious for pleasant work to do, have not invented something which would get rid of this clumsy business of going up-stairs by means of these rude contrivances.
Dick laughed. My dear friend, said he, as long as water has the clumsy habit of running down hill, I fear we must humour it by going up-stairs when we have our faces turned from the sea. And really I don't see why you should fall foul of Maple-Durham lock, which I think a very pretty place.
There was no doubt about the latter assertion, I thought, as I looked up at the overhanging boughs of the great trees, with the sun coming glittering through the leaves, and listened to the song of the summer blackbirds as it mingled with the sound of the backwater near us.
So not being able to say why I wanted the locks away, which, indeed, I didn't do at all, I held my peace. But Walter said
You see, guest, this is not an age of inventions. The last epoch did all that for us, and we are now content to use such of its inventions as we find handy, and leaving those alone which we don't want. I believe, as a matter of fact, that some time ago (I can't give you a date) some elaborate machinery was used for the locks, though people did not go so far as try to make the water run up hill. However, it was troublesome, I suppose, and the simple hatches, and the gates, with a big counterpoising beam, were found to answer every purpose, and were easily mended when wanted with material always to hand: so here they are, as you see.
Besides, said Dick, this kind of lock is pretty, as you can see; and I can't help thinking that your machine-lock, winding up like a watch, would have been ugly and would have spoiled the look of the river: and that is surely reason enough for keeping such locks as these.

Good-bye, old fellow! said he to the lock, as he pushed us out through the now open gates by a vigorous stroke of the boat-hook. May you live long, and have your green old age renewed for ever!

Ironically in 1956 this became the first powered lock on the Thames!

1885: Mapledurham Lock, Henry Taunt -

Mapledurham Lock, Henry Taunt, 1885
© Oxfordshire County Council Photographic Archive; HT5144

1886: Miss Sailor-Boy, Mapledurham Lock, August, Joseph Ashby-Sterry -

I pause and watch the boats go by,
And paint her portrait on the sly !
 
Her age is twelve;  half bold, half coy
Her friends all call her Sailor-Boy
With sweet brown eyes beyond compare,
And close-cropped, curling, sunny hair;
Her smart straw hat you'll notice, and
See Jennie broidered on the band,
Her sailor's knot and lanyard too,
With jersey trim of navy blue;
Her short serge frock distinctly shows
Well shapen legs in sable hose
And symphonies in needlework,
Where dimpled pearly shadows lurk
Which, as she swings her skirts, you note
Peep out beneath her petticoat.
This sunburnt baby dives and floats,
She manages canoes or boats;
Can steer and scull, can reef or row.
Or punt or paddle, fish or tow.
The lithest lass you e'er could see
In all Short-petticoaterie !

Joseph!  Are you still taking your medicine?

1890:  Mapledurham Lock, Francis Frith -

1890:  Mapledurham Lock

1890

Mapledurham Weir, lantern slide 1883-1906, W.C.Hughes, research by Dr Wilson, courtesy of Pat Furley

Mapledurham from above lock, lantern slide 1883-1906, W.C.Hughes, research by Dr Wilson, courtesy of Pat Furley

1906: G.E.Mitton -

Mapledurham is greatly spoilt by the churlishness of its main landlord. The lock-keeper is strictly forbidden to ferry anyone across the river, and though the crossing would be but short, and would involve only a walk of a few seconds along the bank to the mill, it is not permitted. The place certainly is worth some trouble, but it is small, and the restrictions are tiresome. The fine old Elizabethan house is a real mansion of the good old sort; one could imagine endless stories of romance connected with it.

1908:  The Lock was rebuilt beside the old one, and greatly enlarged. Fred Thacker -

I well remember the stream through the old lock when filling, due to the leaky condition of the lower gates.

1908

1917: Mapledurham Lock, Francis Frith -

1917: Mapledurham Lock, Francis Frith

1955/6: Electro mechanical gear installed which made this the first powered lock on the Thames.
Rymer and paddles in the 1970s:

Rymer & Paddles, 1970s

1973: Hydraulic power installed.

Mapledurham Lock

Mapledurham Weir 2020
Notice the walkway stops short of the Mapledurham bank