From
comparison of the route options assessed in this report the preferred route is:
·
Green between Nodes 1
to 3, and;
·
Yellow between Nodes
3 and 16
For
details of the development of the routes, refer to Chapter 3.
The object of route
location: “to determine the most economically feasible route between a given
set of termini that combines the need of the travelling public with the
interests of the local area in a manner that is environmentally, socially and
politically responsive” – Everett S. Preston, Handbook of Highway Engineering,
1982.
In order to best evaluate
the interaction between the relative potential impacts associated with each of
the route options, a workshop was conducted on Wednesday 14 November 2001, at
which key personnel of the route selection team reviewed and assessed the
results of the comparative assessment in order to select an emerging preferred
route for the scheme.
The personnel involved in
this workshop included representatives from Cork County Council and McCarthy
Hyder Consultants. An independent
professional engineer, provided by P.H. McCarthy & Partners, was appointed
as facilitator for the workshop.
In consideration of the
results of the comparative assessment, the route selection team addressed the
following broad categories/impacts for each of the route options:-
environmental, social, technical and economic.
The routes have been
compared between the converging nodes:
· Tie-in west of Ballyvourney (node 1) to a point
north of Ballymakeery (node 3) - Comparison of Green and Yellow options
· Point north of Ballymakeery (node 3) to Macroom
(node 6) - Comparison of Green, Yellow and Green/Link/Yellow routes
· Northern options: comparison of Green, Red and
Green/Link/Red routes
· Southern options:
· Comparison of Yellow, Blue and Yellow/Link/Blue
routes between Macroom (node 6) and Lissarda (node 11)
· Comparison of Yellow, Blue and Yellow/Link/Blue
routes between Lissarda (node 11) and proposed Ballincollig bypass (node 16)
· Comparison of preferred northern and southern
options between Macroom (node 6) to the tie-in with the proposed Ballincollig
bypass (node 16).
All the routes have been
assessed against different environmental and engineering criteria to identify
and grade the potential impacts associated with each of the Route
Sections. These assessments are given
in Chapters 4 to 20 and a summary is given in the Comparative Assessment
Matrices (Appendix 21). From the conclusions of these Chapters, it
can be seen that a favourable route for a particular criteria may have an adverse
impact on another criteria.
For each option between
the segments the impact of the various subject areas has been ranked as
follows:
|
Significance Criteria |
Level |
|
Moderate beneficial
impact |
A |
|
Minor beneficial impact |
B |
|
No impact |
C |
|
Minor adverse impact |
D |
|
Moderate adverse impact |
E |
|
Major adverse impact |
F |
|
Severe adverse impact |
G |
These relative impacts are
more thoroughly defined within each of the chapters (4 to 20) specifically
dealing with the particular type of impact.
Section 50 of the Roads
Act 1993, the Roads (Amendment Act 1998) and the Roads Regulations 1994 (SI No.
119 of 1994) give effect to the EC Directive 85/337/EC ‘on the assessment of
the effects of certain public and private projects on the environment’. This Directive was amended by EC Directive
97/11/EC, which was implemented by the EC (Environmental Impact Assessment)
(Amendment) Regulations 1999 (SI No. 93/ 1999).
Section 50 of the Roads
Act, 1993, sets out the requirements for an Environmental Impact Statement by a
road authority. This Section states
that an Environmental Impact Statement must be prepared for “any prescribed
type of proposed road development consisting of the construction of a proposed
public road or the improvement of an existing public road.”
In addition to this,
Section 50 also makes provision for a direction to be given by the Minister, in
consultation with the relevant road authority, to prepare an Environmental
Impact Statement for a proposed road development, where the Minister (or the
road authority) considers that the “proposed road development … would be likely
to have significant effects on the environment”.
Comparison of Green and
Yellow Routes between node 1 and 3 - preferred route for this section is GREEN.
The economic,
archaeological, ecological, agricultural and landscape impacts are all similar
for both routes.
The reason for the
preference of the Green route is due to negative elements on the Yellow
route. In order to achieve the
necessary change in direction, the Yellow route alignment will require a roundabout
at the connection to the existing N22 west of Ballyvourney. The use of a roundabout in this location
would affect journey times. Although a
roundabout may be an option for the Green route, the necessity of this junction
would place a restriction on the next phase of the design process.
Whilst construction of the
tie-in to the existing road west of Ballyvourney would cause some disruption to
traffic by both routes, the Yellow route would entail improvement along the
existing N22 between the proposed junction and the existing wide single
carriageway thereby creating more disturbance than the Green route.
Areas that will need to be
addressed during the preliminary design are to minimise the effect on Cascade
Wood and junction design to tie-in to the existing N22 west of Ballyvourney
from wide single carriageway to standard single carriageway cross-section. Neither of the routes would require
demolition of residential dwellings.
In order to mitigate against
loss of passing trade to Ballyvourney, design of signing will need to be
addressed at detailed design stage.
Both routes have a major
adverse impact on site 1b (Cascade Wood), which is of high ecological value and
may correspond to the Annex I habitat ‘Old Sessile Oak Woodland’. Alternative routes have been assessed to the
north of Cascade Wood, but these would result in severe adverse visual impact
due to large cuttings into the hillside above Ballyvourney and, in addition to
this, the tie-in to the existing N22 would be “pushed” further to the west due
to geometric design constraints.
Cascade Wood is also designated as an area of scientific importance
(D25) within the South Cork County Development Plan (199b) and is used as an
amenity by the local population.
The construction of the
tie-in on the existing N22 would cause some disruption to traffic.
Comparison of Green,
Yellow and Green/Link/Yellow routes - preferred route is YELLOW.
With respect to
environment, there are important ecological and archaeological concerns within
this section. However, when the routes
are compared, the Yellow route is preferable for most criteria.
Overall, between
Ballyvourney and Macroom, the Yellow route has the lowest scheme cost and
greatest benefit cost ratio.
Both the Green and
Green/Link/Yellow routes would cross sites of high or potentially high
ecological value, both of which may correspond to Annex 1 habitat “Old Sessile
Oak Woodland”. The Yellow route does not pass through any sites of high
ecological value, although it does pass close to Prohus Wood pNHA. Measures should be identified during the
preliminary design and detailed environmental survey to avoid or minimise
secondary impacts on Prohus Wood pNHA.
The Green/Link/Yellow
would result in fewer cultural heritage sites sustaining a major or moderate
impact than the Green or the Yellow routes.
The Green route would have a major impact on the greatest number of
sites and monuments (5), one more than the Yellow route (4).
In comparison to the
Yellow route, the Green and Green/Link/Yellow route pass through relatively
undeveloped rural areas. The proposed
Yellow route will affect the landscape seen by more residential properties than
the Green or Green/Link Yellow routes, however, these properties are already
affected by the existing road and gain the benefit of access to a national
road.
Surface water quality is
also an important consideration in this section. The Yellow route would cross the fewest rivers classified as
Class A. Although it would run
alongside the River Sullane, a drainage system could be installed that would
potentially reduce the pollutant load that the river currently receives as
run-off from the existing N22.
The Green /Link/Yellow
route is considered to represent a localised and limited increase to the flood
risk of the Foherish River.
In terms of agriculture,
the Yellow route is preferable because, although requiring greater landtake,
the quality of land is poorer.
The Green route would
result in splitting the community of Clondrohid and would result in loss of
passing trade to existing businesses along the existing N22. The Yellow and the Green/Link/Yellow routes
would also result in a loss of passing trade and would split the small
community of Clonfadda. However,
signing from the proposed Yellow route may help to mitigate the loss of passing
trade along the existing N22.
Mitigation measures to be
investigated at preliminary design stage include minimising secondary impacts
to Prohus Wood, the archaeological resource and drainage in the vicinity the
River Sullane.
Comparison of Green, Red
and Green/Link/Red route - preferred route is GREEN.
All these routes pass
though an area dominated by the Lee Valley reservoir where there are important
issues concerning the crossing and construction of the road close to the banks
of the reservoir.
The Red route provides the
best economic benefit, however, there are environmental concerns associated
with this route.
All the options must cross
the river Bride at Ovens. There are no
areas of habitat of a type listed in the Habitats Directive. All three routes
cross through at least one area of high or potentially high ecological value.
The Green route crosses one only, whereas the Green/Link/Red and the Red route
cross 2 and 3 sites respectively.
The Green route passes
very close to an ecclesiastical site at Ballineadig (Site NIS058) but this is
far outweighed by the dense archaeological landscape with potential for
sub-surface archaeological sites along the Red route. The Green route would
have a major impact on one more site or monument than the Green/Link/Red
route. Minimising the effect on Site
NIS058 could be taken into account in the preliminary design.
The Lee Valley reservoir
is an important landscape resource and the area is promoted as a tourist
location for fishing and other water-based activities. The Green route is preferred in terms of
landscape as although it crosses the Lee Valley Area of Scenic Importance, it
passes along the reservoir shores for the shortest distance. There are also flood risks associated with
the Green/Link/Red and Red routes.
The Green route has a
shorter length of high embankment (15m maximum height). This route passes close to the closed
landfill site at Shanakill and measures should be taken to ensure that impact
due to construction near the landfill is mitigated. The Red and Green/Link/Red routes have 23.5m maximum embankment
height and longer lengths of high embankment.
All routes would result in
loss of passing trade currently attracted to businesses along the existing N22.
On the negative side, the
Green route affects significantly better quality land than the other options
and would sterilise areas of proposed extraction at O’Neil’s quarry near
Clashanure.
Comparison of Yellow, Blue
and Yellow/Link/Blue route - preferred route is YELLOW.
Overall, between Macroom
and Ballincollig, the Blue route has a higher benefit cost ratio over the 20 year
analysis period.
Yellow is chosen firstly
due the high impact on archaeological sites by the Blue route, and secondly due
to the higher impact in terms of ecology, noise, vibration and air quality on
the Yellow/Link/Blue route when compared with the Yellow route.
The Blue route would
impact upon a large area of high archaeological potential situated in the
vicinity of Mashanaglass. There are
many sites already recorded in this area and the density suggests that there
could well be other subsurface sites.
Due to the importance and density of this area, the Blue route would
have an unacceptable impact on the cultural heritage of the area. It is for this reason that the Blue route is
the least preferred option.
The remaining two routes
of Yellow and Yellow/Link/Blue differ in alignment at the bypass for Lissarda
(between nodes 8 and 11). These routes
are quite similar with respect to cultural heritage, but the Yellow route would
affect fewer recorded sites than the Yellow/Link/Blue route.
The Yellow and
Yellow/Link/Blue would also have a similar impact on the ecology of the
area. Both would pass through sites of
high or potentially high ecological value, the Yellow route passing through an
area of marshy grassland, and the Yellow/Link/Blue route through, an area of
coniferous and broad-leaved woodland
All routes cross the
Carrigadrohid reservoir. The
Yellow/Link/Blue route has potential to affect flooding to residential
properties. On this basis the Yellow
route is preferred with respect to surface water impacts, however localised and
limited changes to the run off may change flood risk to agricultural land.
It was acknowledged that
the Yellow route would have a severe impact in terms of landscape, air quality
and noise impact on Lissarda, as this route is close to properties in the
village. These impacts are lessened to
some degree by virtue of the fact that Lissarda is already on the existing N22
and thus experiences these affects to a certain degree. The Yellow/Link/Blue route would affect more
rural areas, which is deemed to have a higher impact.
A more detailed
consideration of the surface water, air quality and noise impact leading to
mitigation measures would need to be completed at preliminary design stage.
Comparison of Yellow, Blue
and Yellow/Link/Blue route - preferred route is YELLOW.
Overall, between Macroom
and Ballincollig, the Blue route has a higher benefit cost ratio over the 20
year analysis period.
Yellow is selected in this
section for ecological, socio-economic and archaeological considerations.
The proximity of the Blue
route to Kilcrea Friary and graveyard would seriously compromise/affect the
setting of this nationally important site and for this reason, the Blue route
from Node 11 to Node 12a is the least preferred route.
The River Bride has been
proposed by the Irish NGOs for consideration as a SAC. The River Bride is the most important
salmonid river in the region, and the SWRFB have expressed concern regarding
the proximity of the route to the river in particular with regard to silty
run-off during the construction phase. The Yellow route would be close to the
river between node 11 and node 12, as it generally follows the line of the
existing N22, which already runs alongside the river. Although construction of
the proposed road would increase the area of run-off from the road, it is
anticipated that improvements to the road drainage system would counteract this
during the operational phase of the road. However, the Yellow route would cross
fewer of the Bride’s tributaries over this section (11-12a) than the Blue
route. The Yellow route would be preferred over this section, despite its
proximity to the River Bride, due to the likely impact on Kilcrea Friary from
the Blue Route. Sensitive construction
practices and mechanisms to prevent water pollution could be implemented to
minimise any impact to watercourses.
Between nodes 12a and node 15, the Yellow route is further from the
River Bride, and is preferred over this stretch for this reason.
All routes represent a
widespread increase in flood risk to agricultural land and a number of
properties close to the River Bride.
All the routes cross
notable areas of productive mineral deposits some of which may be sterilised by
the scheme. This conflicts with Cork CC
policies to protect mineral resources in the county and would have the
potential to adversely affect employment in the area. The Yellow route would potentially have the most impact on
mineral resources, as it would cross the deeper northern vein of gravel. The Blue route would traverse the
significantly shallower southern vein.
However, this is considered less significant when compared to the potential
environmental impact of the Blue route.
The preliminary design may be able to minimise the areas sterilized.
Comparison of Green route
(preferred northern route) and Yellow route (preferred southern route) -
preferred route is YELLOW.
The Yellow route is
preferred on socio-economic and visual impact grounds.
There would be more traffic attracted to the Yellow route than the Green
route. The difference in predicted
traffic volume is attributed to the traffic demand for the southern routes to
Bandon, Crookstown, Kilmurray and West Cork.
Should the Green route be preferred there would still be demand for
Bandon to West Cork traffic using the existing N22 (which would be down-graded
to regional or local route following construction of the new road). With the Yellow
route taking more traffic away from the existing N22 safety may improve on the
existing road.
Commercial development has generally followed the existing N22 and with
the Yellow route generally following this alignment, the existing commercial
traffic can access the proposed route with minimum disruption. Signing for local services may mitigate loss
of passing trade for the Yellow route.
Reduction in passing trade would likely be much greater with the Green
route as traffic is taken far away from the existing services and businesses
(for example: B&B, petrol stations and restaurants).
In respect of noise and air quality, the majority of the properties that
would be affected by the proposed Yellow route are also currently (and
similarly) affected by the existing N22.
Therefore, the resulting change in conditions (noise and air quality) is
predicted to be less for properties on the Yellow route than it would be for
those on the Green route, which are currently located in a relatively quiet
rural environment.
The reservoir crossing for the Yellow route is shorter and close to the
existing N22 crossing. The Green route would include construction of a greater
length of reservoir crossing at a location that is designated as an Area of
Scenic Importance in the South Cork Development Plan. The route would also be
highly visible from two scenic routes also designated in the plan. The Inishcarra Lee Valley reservoir is also
designated as an Area of Recreational importance promoted as a tourist attraction
for water based recreational activities.
The Yellow route would
have least affect on the landscape; however, it would have the most visual
impact in terms of affecting views from residential areas. There would be a small number of visual
receptors along the Green route, which would be located in a largely scenic
area, passing through the locally designated area of the Lee Valley.
Both routes would have a
similar impact with regards to cultural heritage.
The Green route crosses 11
low value ecological sites and 1 high ecological value site, whereas the Yellow
route crosses 16 low value ecological sites and 3 high ecological value
sites.
The Bride River is widely
regarded as the most productive salmonid river of the region, and its
tributaries, even those that are small or unclassified, serve as important
spawning and nursery habitat. The South
Western Regional Fisheries Board has stressed the importance of this river
system, and has stated their preference that the preferred route avoids it
altogether. It should be noted however, that the Yellow route generally follows
the existing N22, the run-off from which may already enter the river. The installation of a drainage system, which
might include gully pots and oil interceptors, on the proposed Yellow route,
could mitigate the additional run-off from the increased road surface. The Green route, which also has a crossing
of the River Bride (at Ovens), could have a potential adverse impact on the
potable water supply to the Cork area due to its crossing of and close
proximity to the Inishcarra reservoir.
The Yellow route would
have a potential impact on the River Bride flood plain such that vulnerable
infrastructure near the proposed crossings of this river may be subject to
increased flood risk. Flooding of the
Bride Valley is a major issue and mitigation measures will need to be developed
in full detail during the preliminary and detail design stages.
The preferred route is:
· Green between Nodes 1 to 3, and;
· Yellow between Nodes 3 and 16