THE ORIGIN OF THE NORFOLK BROADS

"The main difficulty [with the theory of a man-made origin] lay in understanding how many great peat cuttings to a depth of 10-12 ft. or more could have been made in the face of water infiltration.

   The new Yarmouth evidence goes far to resolve the difficulty. For if the whole area once stood at least 10 ft. higher above sea-level, the reduced high-water area in the lower estuary would have led to a fall in the upper-valley fresh-water table. The possibility of cutting peat and the subsequent flooding of the hollows as the medieval trangression progresses are explicable even easy to understand."

                                        Charles Green, The Times, 14th May. 1956

Too easy.

The simple idea that great, formerly dry peat pits flooded subsequently when the sea level rose remains deeply embedded in the public psyche, despite the fact that the single body of evidence supporting it has been discredited for over thirty years.

Many misconceived notions stem directly or indirectly from this idea. Most of them became untenable in the light of the now generally accepted facts about medieval water levels, and of Martin George's lucid deduction that the broads must have originated as separate, fairly small peat pits;  yet common misconceptions still remain uncritically welded to the customary account of how the broads were created:

• Turves could only be dug or cut with turf-spades in a turbary which was completely free of water.
• Formerly dry turbaries became flooded one after another, over a period of about a hundred years, with 'downstream' turbaries  flooding first, 'upstream' turbaries later.
• Entire turbaries, having been kept free of water, became 'partially' flooded before they became 'completely' flooded, perhaps some decades later.
• Peat could only be dredged up in bulk and shaped into turves in turbaries which were 'partially' flooded.
• The purpose of dredging up peat in bulk and shaping it into turves was to maintain supplies of the high quality brushwood peat when a turbary had become flooded.
• Peat pits required 'maintenance', that is to say  bailing at regular intervals year after year so that more peat could be dug from them.

Not least:

• The turbaries were abandoned one by one when the depth of the flooding made further peat extraction impossible or uneconomic.

What were the effects of the dire weather at the start of the fourteenth century? Peat was clearly caught up in the same cycle of inflation and deflation that affected commodity prices nationally (see under "The price of peat"). The minimal data available suggests that in the first three decades

• peat prices and production costs increased, fluctuated, and then fell  back to thirteenth century levels.
• production at Martham and Hemsby increased;
• imports by Norwich Cathedral Priory increased.

Unlike other commodities, exceptional cold and exceptional rainfall would have stimulated demand for peat, as well as inhibiting supply. Price inflation demonstrates that the former exceeded the latter, but the facts also suggest that production methods were far from overwhelmed.

In any years when there was standing water on the surface of the turbaries at the time of the peat 'season', or water levels were very near the surface of the fen, then any digging, even of surface peat, would have been impossible. Turves could still have been shaped from bulk peat, but volume output would have been restricted. On the other hand, the evidence is that the most serious floods occurred in the autumn, well after the year's stocks of turves had been produced. When the weather improved, peat prices and costs fell back to thirteenth century levels.

• From 1340 onwards there is no evidence that peat production was inhibited either by the weather or by the environment.

Why would it have been? The climate was generally cooler and wetter than the Medieval Climate Optimum of previous centuries, but the evidence tells us that water levels, although rising very slowly, were still lower than they are today.

"The Black Death arrived in Norfolk in the spring of 1349 and spread up the river valleys from Yarmouth. It was particularly severe in South Norfolk, along the Yare and Bure valleys and on the coast."                                                                           Cornford, 2002

 "As local population levels fell dramatically in the wake of the Black Death, however, the costs of extraction and pit maintenance would have escalated, while the demand for peat - and thus the profits to be made from its extraction would have declined. In such circumstances, it is hardly surprising that no further deep pits were dug, and those already in operation were abandoned. Extraction continued but on a smaller scale, principally to satisfy domestic needs." Williamson, 1997

Apart from a superfluous reference to 'pit maintenance', here is an assessment which accords with the actual evidence. Land owners had to pay 4d. for a thousand turves to be dug by the 1380's, only 1d. before the Black Death.

• For the majority, who did their own digging in their own dole or rented plot, turves would have cost no more.
• Martham purchased turves at 14d. per 1000 in 1388-9 and 12d. in 1390-91, so the margins were still there. It was the volume which had disappeared.
  

Added to which,

"In Hoveton, bond turbary was accumulating in the lord's lands in the early 1350's . . . . . In the manor of Burgh Vaux, bond turbary was tending to fall to the lord's lands by 1336."               Smith, 1960

The movement of people away from the country into the towns continued throughout the fourteeenth century, leaving more and more land to accumulate in this way, to which was added the land of families who were wiped out by the Black Death, leaving no heirs.

• Not only was there no mass market for profitable sales, but some manors acquired a surfeit of land which had been designated as turbary.

It is thus also hardly surprising that

"There is in fact a long period of transition in the late fourteenth and fifteenth centuries when the usual way of describing the old turbaries changes to first to "fen" (mora) and then in a few cases to "water and marsh" or "water and fen"".                                               Smith, 1960

• Surplus areas of intact turbary were put to better use (see also under "The transition evidence").

To conserve land, peat production would have been concentrated on  the extraction of all the reserves from those parts of existing turbaries which could not be put to better use, in particular the walls of peat left as divisions within and between the doles and rented sections of the turbary. That is exactly what they were doing in the first half of the fifteenth century "on the several pondwaters of the lord" at Bartonbury Hall, and this process of broadening the several pondwaters into fisheries and larger areas of open water may well have lasted into the sixteenth century at some locations.

It is generally accepted that no new areas of deep turbary were created after 1350, but, despite the increasing availability of other (probably superior) fuels, peat was still a cheap option, and production in Broadland  expanded again considerably in the nineteenth century  (vid. Williamson, 1997, pp.100-104), continuing into the early twentieth century.

However, although the 'superior', deep brushwood peat could have been dug by hand, just as it still can be today, turves were usually only cut from the 'inferior'  peat on the surface, creating shallow turf ponds.(Williamson suggests that some nineteenth century diggings were two metres deep).

• This was clearly a deliberate decision, and not something dictated by environmental factors or cost considerations.

Martin George provides the explanation in Chapter 7 of his book, which deals with "The Natural History of the Fens, Past and Present":

". . . . most turf ponds would have been quickly colonised by Reedmace and other peat forming species, and the majority have subsequently been completely occluded by the fresh peat formed by such communities. Indeed, in many cases the only signs that a fen gas been exploited as a sourse of peat are the lines of bushes or trees alomg the edge of the former turf pond, and a slight lowering of their surface relief compared with adjoining unworked areas." 

"The exact rate at which the infilling took place cannot be determined . . . . . Nevertheless, according to Gunn (1864), derelict workings in the Ant valley were subject to a rate of peat 'growth' of a foot (30.5 cm) in twenty years - a high rate, but one comparable with an estimate (by turf cutters) of twenty inches (51 cm) in sixteen years from the fens at Isleham (Babbington. 1860). In contrast, the mean rate of accumulation in those parts of Catfield Fen which have never been exploites as a source of peat has been only about 0.75 mm per year during the past 2000 years (Wheeler and Giller, 1982a)."                                                                          George, 1992

• Extracting the surface peat temporarily affects the productive potential of the land, but ultimately preserves it.
• Extracting the deep peat permanently destroys the land - a fact still obvious after eight hundred years.

There is thus every reason to conclude that the practice of deep peat digging came to an end just as it had started, as a response to new socio-economic pressures.

• The practice ended after the climate changed, but to conclude that the latter was the cause of the former is to argue post hoc ergo propter hoc without any factual foundation.

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