1998:575 - SLIGO AND ENVIRONS WATER SUPPLY SCHEME, Sligo

The upper weir
The upper weir (1697 3359) on the Garvoge River in Rathquarter and Abbeyquarter North in Sligo town, built sometime between 1808 and 1815, may have been a successor to the weirs of Sligo's Dominican Abbey, c. 250m downriver. Newspaper references to clearing the bed of the river in the 1840s, upriver of the Upper Weir, may indicate the presence of earlier weirs and that the early 19th-century one was built with the protection of those earlier structures.

A bund was built in late 1997 around the old Upper Weir, and the worst section was broken through under archaeological observation. Nothing of an earlier structure was encountered, and so the old weir structure was progressively demolished. The structure was one of large blocks of limestone, presumably quarried from the bed of the river, used to form the sides and top of the weir, with smaller stones, down to the size of gravel, used to fill the core.

A damaged quernstone was discovered in the make-up of the weir near its north end in Rathquarter.

More interesting was the discovery of a layer of dense, sticky, blue clay, partially under but also upriver of the weir. It may be that the weir was built on this layer but, owing to the pressure of the water and damage to the weir, moved downriver by about a metre. No other archaeology was recovered. The new weir was completed in autumn 1998. It holds the water at what was the winter level on Lough Gill.

Rising main
Work on a new pumping station and initial work for a new rising main in Carns townland began in January 1998. There was archaeological involvement, though not from the outset. The greater part of the length of the strip for the pipeline proved to be archaeologically sterile.

At the north end of the pipeline the cut crossed (1703 3343) an old lane leading from a limestone quarry and a limekiln on the east side of Carns Hill towards Sligo town. A single layer of stones, generally no more than 0.15m in diameter, was used in the make-up of this road. Adjacent to the lane, but untouched by the development, are the foundations of a house (1704 3342) that may have been contemporary with the lane and the quarrying.

Midway along the pipeline and just downhill of the current road, which was constructed after 1837, are the probable foundations of another house of unknown antiquity (1711 3342), built on a platform cut into the slope between the current road and the pipeline. The development avoided this platform by less than 2m.

On the slopes downhill from the former Belvoir House and Belvoir Wood, in a stretch where the soil had considerable amounts of broken crockery, four concentrations of burnt stone and soil were encountered. The first three (1712 3340; 1713 3339; 1713 3338) were at the west edge of the cut and were not disturbed. Insufficient was exposed to establish the intensity or extents of use of these fulachta fiadh deposits. Their positions were marked by steel rods, and they were covered over with clay.

The fourth (1713 3337), the throw-out material from a fulacht fiadha, was more disturbed by the cut for the pipeline. The location had been soil-stripped, and the ground had been levelled by cutting into the hill to make a working platform for pipe-laying. This was done without the presence of an archaeologist until mid-January 1998. At the time of walking the line in early February 1998 there was no indication of any archaeological feature here or anywhere else on the line. When the pipe was being laid in July considerable deposits of burnt stone, black soil and sizeable pieces of charcoal were disturbed in an area 8m x 1.5m, within the area prepared by mid-January and then apparently devoid of any archaeological potential. This area was covered over with soil in September. There was no indication of a trough, a hearth or a cairn, and no objects were seen.

Water treatment plant field at the Fox's Den in Carns (Duke)
The water treatment plant field at the Fox's Den in Carns (Duke) lies between, but at a lower level than, the passage tomb cairns on Cairns Hill West (SMR 14:231) and Cairns Hill East (SMR 14:232). The cairns are at distances of 150m and 250m respectively. A geophysics survey of this field was carried out by GeoArc, and all the anomalies found had a geological explanation. Two hearths and the burning pit and burnt stones of a fulacht fiadh were encountered and recorded during the soil-stripping of this field. No indications of these were given until the topsoil had been completely removed and the B horizon material was being layered off. There were no finds, and the research is still incomplete.

Nothing else of an archaeological nature was encountered.

Further monitoring took place in several phases during the autumn in Carns (Carbury Barony) and Carns (Duke) townlands. The third area covered by this licence, that for the break pressure tanks in Tonaphubble, will be excavated when weather conditions allow for transporting the soil through the suburban area of Tonaphubble.

Carns (Carbury Barony)
No archaeological significance1713 3339
Monitoring of the laying of land drainage pipes down from the rising main between the new pumphouse in Carns and the new water treatment plant in Carns (Duke) took place in September 1998, in four separate but adjacent areas.

The first was in an area where the Garvoge River narrows as it leaves Lough Gill. A promontory fort, SMR 15:91, is on a dry hill at the edge of the river, just downriver of this first area. The very wet ground consisted of silts deposited in times of high water-levels. Approximately 220m of plastic drainage piping was laid in seven trenches 0.5–0.8m wide and averaging 0.6m deep. There was evidence of at least two earlier efforts to drain this area. Nothing of an archaeological nature was encountered.

The second area was a single conduit scour pipe to take the water accumulating along the rising main down to the Garvoge. The cut was 77m long and narrowed from 2m wide at the rising-main end to 0.5m wide at the river edge. At the rising-main end the cut was 2m deep and V-shaped, and thereafter it reduced to 0.6m deep.

Nothing of an archaeological nature was encountered, although a small area (1713 3338) of burnt stone and sooty soil had earlier been encountered but not disturbed 5m north-west of the rising-main end of this drainage pipe during the laying of the rising main itself.

The third area, just east of Belvoir Wood, was 40m x 30m, showed evidence of several springs and was very soft. Approximately 160m of land drainage piping was laid down in several sections. Nothing of an archaeological nature was encountered.

The fourth area was a single scour conduit pipe to take the water accumulating along the rising main down to the Garvoge. The cut was 65m long and narrowed from 3m wide at the top to 0.5m wide at the river edge, where it was through river silts. At the rising-main end the cut was 4m deep, and thereafter it reduced to 0.6m deep.

Nothing of an archaeological nature was encountered, although an area (1713 3337) of burnt stone, black soil and sizeable pieces of charcoal had earlier been encountered just north of the high end of this drainage pipe during the laying of the rising main.

Carns (Duke) and Carns (Carbury Barony)
No archaeological significance 1706 3340
There was no known archaeology within the length of 380m to be disturbed for the inter-connector pipeline between the old water treatment plant on the Green Road in Carns (Carbury Barony) and the new one in Carns (Duke). Monitoring took place from 26 August 1998. The cut for the pipe was 1.5m wide and varied in depth, depending on the topography, from 0.8m at the south end to 2.7m at the north end. A working strip 9m wide had to be desodded to allow machinery and materials access. At one stage towards the south end the alignment of the cut had to be adjusted, and so the strip was almost double width for a length of c. 50m. Soil-stripping of the space, 20m x 20m, for a cattle crush (1705 3335) south of this strip and south-east of the old water treatment plant was also monitored. The limestone bedrock was immediately under the 50mm-thick sod. Nothing of an archaeological nature was encountered.

Bóthar an Corran, Keash, Co. Sligo