Hydro G Final report - Kildare.ie

Hydro-G FINAL REPORT
1. Introduction
In December 2007, Hydro-G was engaged by Kildare County Council to investigate and evaluate
water resources within Leixlip Spa, Co. Kildare in light of increasing concerns about the site’s
ecological health and integrity.
The site is located on the outskirts of Leixlip, approximately 2km west of the town, between the Intel
Ireland factory and the Royal Canal. The national grid reference for the site is 299500, 236500. The
location map is presented in Figure 1. The site constitutes part of the Rye Water Valley Special Area
of Conservation (site code: 001398) containing protected habitats including calcareous grassland and
petrifying tufa springs, as well as rare and protected species of fauna including molluscs species
Vertigo moulinsiana and Vertigo angustior.
Topographically, the Leixlip Spa site lies on number of terraces carved in limestone bedrock, which
were created during construction of the Royal Canal in the 18 th century. This bedrock exposure
resulted in a number of wetland habitats that developed on subsequent terraces in response to a
continuous discharge of water from the bedrock. The entire area of the site is 6000m 2 ,
approximately, 40m wide and 150m long with a topographic drop of 20m in a south-north direction
towards the river Rye Water.
In addition to its high ecological values the Leixlip Spa is known also for its archaeological features
including a hexagonal well and a Roman Bath which were created in the 18 th Century following a
discovery of a hot spring. The hot spring that supplies water to this Bath was discovered during the
construction of the Royal Canal and water from the spring is highly mineralised, specifically rich in
iron, for which it gained its spa status. The original hot spring is located underneath the Royal Canal
and was diverted to a man-build Spa Well of a hexagonal shape that is located at the eastern side of
the entrance to the site.
The ecological and archaeological features of the Leixlip Spa have been extensively investigated
throughout decades and some documentation dates back as far as the 18 th century. Nevertheless, it
is the site’s unique fauna and flora that have been given most attention following the implementation
of the EU Habitats Directive (92/43/EEC). The site’s ecological features are reported to have
deteriorated over recent years and as the majority of the area comprises wetland habitats, there is a
possibility that changes in the site’s hydrological controls merits investigation (Moorkens, Dooge,
pers. comm.).
1.1. Project Objectives
Kildare County Council engaged Hydro-G to investigate the hydrological regime of the Leixlip Spa site
and to develop a water management strategy to prevent further deterioration and to facilitate
sustainable conditions.
The specific objectives of the project were specified by Kildare County Council, as follows:
“The objective of this hydrological study is to determine the movement of water through out the site
to determine how this water can be used most efficiently to maintain the conservation status of the
site particularily in relation to the Shining Sickle Moss (Drepanocladus vernicosus) and the semi
aquatic snail species Vertigo angustior and Vertigo moulinsiana”.
Project No.: 07_136 -1-
Leixlip Spa