Arboricultural Constraints report - Rochford District...Arboriculture who will arrange for a...
Transcript of Arboricultural Constraints report - Rochford District...Arboriculture who will arrange for a...
Arboricultural Constraints Report
for
Land South West of Hullbridge
carried out on behalf of
Southern and Regional Developments Ltd
by
JBA Consultancy Services Ltd
Job No: 10/252 - AR01 September 2014
Rev A 30.10.2014
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NON-TECHNICAL SUMMARY
1.0 The following points are explained and qualified in more detail in this report and this
summary is intended for quick reference only. Any actions consequent to this
summary should be discussed with the Head of Arboriculture at JBA before being
undertaken in order to prevent potential breach of tree protection legislation, whether
by planning condition, area planning designation or specific tree preservation order
(which may apply to individual trees, groups, hedges of any size).
1.1 Non-technical Summary:
Site: Land South West of Hullbridge
Overview of Key Tree Constraints: There is a low risk presented by the trees on the site due to their location to the boundary of the site as well as the maturity and quality of the trees.
Overview of Construction Costs - Root Protection Areas:
There is a low risk of increased costs from root protection areas.
Overview of Construction Costs - Special Construction Techniques:
There is a low risk of increased costs from special construction techniques – especially for service runs.
Precautionary measures: Four Category “U” trees are required to be felled.
Designations: Having made an initial desk
top search, I have determined that there the
following designations which apply to this
site:
1. TPOs: TPO/00006/07 APRIL 2007.
2. Conservation Area: No.
3. AONB: unknown.
4. Greenbelt: Green belt boundary runs
along the western and southern site
boundaries.
5. Planning Conditions: Yes.
Pernicious Weeds found: 1. Japanese Knotweed: No
2. Giant Hogweed: No
3. Poison Hemlock: No
4. Himalayan Balsam: No
5. Ragwort: No
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6. Horsetail: No
Impact - Number of trees lost Currently four trees are required to be
removed due to their poor structural and
condition.
1.2 Mitigation Measures:
a) Planting: Native trees will be planted where necessary in order to offset any
tree removals as per LPA instructions.
b) Foundation design: Foundations may need to be deepened depending on
layout.
c) No Dig Surfaces: “No-dig” construction methodology may be needed
depending on layout and defined as construction of surfaces and structures
that does not require excavation of the soil. Foundations and bases are laid
over existing soil supported by structural manmade materials. Structures may
require pile or raft foundations. No trenches or excavations are permitted.
1.3 Seasonal Factors:
a) Nesting Bird surveys: Trees / tree groups and hedges will need nesting bird
surveys if works are commenced adjacent to them between the months of
March and September inclusive; a bird survey is to be carried out by a
qualified ecologist.
b) Pruning / Surgery Programme: Trees to be retained on site that require
corrective surgery for reasons of health, access, safety or proximity to
development should not be cut between March and mid-June. This will ensure
that new growth pushed out in the spring has had time to replenish food
stores, or else the plant’s vigour may be harmed.
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1.4 Costs and Programme:
a) Surgery Works: All works should be carried out in accordance with the
BS3998:2010. The following preliminary tree works are recommended.
Tree number
Preliminary tree works
T5, T7, T18, T21 Remove
Note: T5 is a boundary feature of a neighbouring property. Consent for
access will be required from the landowner prior to undertaking works to this
tree.
T1 Remove major deadwood
G2 Remove broken branches
T8, T11 Remove ivy
T6 Sever ivy
b) Accurate Assessment of Cost: For a detailed cost breakdown of the works
and the programme in respect of the above, please contact our Head of
Arboriculture who will arrange for a quotation from a suitably competitive and
qualified contractor.
2.0 INTRODUCTION
2.1 Instructions have been received to assess trees and other significant vegetation
at land South West of Hullbridge in relation to the proposed development. As
such our assessment is to be carried out in accordance with the principles of
BS5837:2012 'Trees in Relation to Construction Recommendations'.
2.2 Trees detailed in the tree survey schedule at Appendix 2 have been visually
inspected from ground level only, with no aerial inspection or any decay detection
equipment used. This report is relevant to the time and date of the survey only.
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2.3 Our report is prepared to assist in the design of development layouts. As
such the report will clearly identify the constraints (both under and above
ground), the quality of the site’s significant vegetation, its contribution to public
amenity and any other constraints particular specimens may offer to the site in
terms of proposed development. The report is a preliminary assessment and
does not include detailed recommendations for tree preservation during and after
construction.
3.0 GENERAL SITE DESCRIPTION
3.1 The Proposal site is situated on the south western edge of Hullbridge. It consists
of several arable and pasture fields. The ground is fairly level with proposed
access routes to the south and east.
3.2 The site’s surroundings are described as follows: The northern boundary is
bordered by a road and existing properties. The eastern boundary is bordered by
existing properties. The southern boundary is bordered by a road and the western
boundary is bordered by arable and pasture fields. The proposed access route to
the south is a new access from Lower Road and the proposed access route to
the east is the extension of an already existing road (Malyons Lane) that
accesses neighbouring residences.
3.3 Along the northern boundary runs a broken, mixed species hedge with occasional
mature trees. The eastern site boundaries are bordered by neighbouring
gardens. Along the southern boundary runs a continuous mixed species hedge
and trees of various ages. The western boundaries are bordered by mainly
continuous mixed species hedges and occasional mature trees.
3.4 There are a few field boundary hedges within the site, mainly continuous and
consisting of mixed species.
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4.0 TREE APPRAISAL
4.1 The site contains a range of species varying in condition, age and quality.
4.2 Seven trees (T6, T11-13 inclusive, T20, T24 and T28) and one hedge (H2) have
been categorised as being of moderate quality providing screening, skyline and
amenity values.
4.3 It would be advisable to retain these trees and hedges where it is practical, due to
their importance within the local landscape which will help to soften the visual
impact of future development.
4.4 Twenty trees (T1-4, T8-10, T14-17, T19, T22-23, T25-27, and T29-31), five
groups (G1-5) and four hedges (H1, H3-5) have been categorised as trees of low
quality with little arboricultural, landscape or conservation value.
4.5 Off-site trees have been identified in close proximity. These should present no
constraint to development in terms of calculated RPAs and canopy spreads. All
offsite trees must be healthily retained unless suitable permission is sought from
the owners. Suitable protective measures will be required to protect RPAs and
canopy spreads.
5.0 CONCLUSIONS AND RECOMMENDATIONS
5.1 Trees detailed in the tree survey schedule at Appendix 2 have been visually
inspected (see note 2.1 Appendix 1), and the following key on-site constraints
should be highlighted. Site boundary trees and hedges should be retained and
will be a high priority for protection by the LPA. They will seek protection of these
trees and hedges and the suitable measures for the protection of the tree root
protection area. There will be concerns in respect to any development with the
minimum distance calculations and any incursion within this zone may be
resisted by the LPA.
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5.2 In the event that incursion is unavoidable, there is a risk of increased
construction costs from specialist construction approaches. Damage to
anchor roots may destabilise the tree and this may cause a CDM risk in terms of
the increased risk of the tree falling in a storm.
Simon Smith
Senior Professional Arboriculturist
For and on behalf of JBA Consultancy Services Ltd
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Appendix 1
Tree Survey Assessment Guidelines and Design Considerations
1.0 TREE SURVEY GUIDE
A1.1 Trees detailed in the tree survey schedule at Appendix 2 have been visually
inspected from ground level only. No aerial inspection has been made, nor has
any decay detection equipment been used.
A1.2 While general comments may be made regarding lower storey trees and shrubs,
only the significant vegetation has been assessed in detail. Trees are detailed in
the schedule either as individuals or as part of a group/woodland as appropriate.
A1.3 Tree details recorded include: their identification number corresponding to their
position on the site plan; species (English name); an estimated height; crown
radius (given for each aspect); height above ground level of lowest branches; an
assessment of the tree’s maturity; a measured trunk diameter at 1.5m above
ground level; calculated root protection radius and area (Table 2 of The BS); a
general description of overall condition; an assessment of the tree’s suitable
longevity; a quality grading (Table 1 of The BS) and some relevant comments
regarding each tree where this is helpful.
A1.4 For your assistance a summary of the system used to grade trees is provided
below:
U grade – trees unsuitable for retention.
A grade – trees of high quality and value, effective for more than 40 years.
B grade – trees of moderate quality and value and/or those estimated to be
suitably retained for 20 to 40 years.
C grade – trees of low quality and value and/or those estimated to be suitably
retained for 10 to 20 years.
A1.5 With reference to the grading system above: Category U trees are those which
for arboricultural or current site reasons should be considered for removal
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irrespective of development proposals. Category C trees are those which
would not normally be considered a reasonable constraint on proposed
development. Category B trees are those which make a long-term and
substantial contribution to the character and appearance of an area and should
therefore ideally be designed around; Category A trees are particularly good
examples of their species, rare or unusual or an essential component of the
landscape. They should be retained and protected.
A1.6 The appended schedule provides a Root Protection Radius (RPR) in centimetres
Root Protection Area (RPA) in square metres. The RPA is the volume of soil that
contains sufficient rooting area to ensure the survival of a tree. The most suitable
way, therefore, to protect a tree is to maintain this area undisturbed throughout
the course of development. However as this ideal situation is not always
reasonable and practicable your attention is drawn to the facility within The BS
that allows for the RPA to be manoeuvred around a tree to a tolerance of 20%
where considered appropriate and where the total RPA is not reduced. In
addition accommodation is also made within The BS for hard standing areas,
(e.g. drives, parking bays and paths) to be constructed within the assessed RPA.
However, this will be subject to arboricultural assessment and implementation of
specially engineered construction methods.
DESIGN CONSTRAINTS AND ADVICE PERTAINING TO TREE ISSUES
A1.7 Consideration should be given to existing site features, natural and man-made
topography and structures that can restrict tree root growth in any direction
causing deeper rooting or a concentration of growth in other directions. In some
situations it may be appropriate to manoeuvre the RPA in excess of the 20%
detailed above if site conditions are expected to have had a significant impact on
rooting habit. Such an assessment must be carried out by an arboriculturist.
A1.8 The BS also accepts that the construction of substantial structures within the
RPA of retained trees may be necessary. It will be important however, to
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consider at the outset of design that continuous open trenching will not be
acceptable within the RPA as set out by the arboriculturist. However,
subject to arboricultural advice, foundations involving piles, pads or slabs
cantilevered as appropriate may be engineered to avoid conflicts with retained
trees. This is on the basis that ground beams or similar are positioned at or
above existing ground levels, which is likely to impact upon internal floor levels
and ridge heights.
A1.9 It should also to be recognised that the design layout needs to provide a realistic
juxtaposition between retained trees and proposed dwellings (or the requirement
for deep excavations such as those for basement accommodation).
Consideration should be given to the potential for retained trees to increase in
size and the implications this may have on structures or living conditions. The
design should make a suitable balance between the amenity benefits of trees to
the scheme and to the surrounding landscape, the potential for conflict or
inconvenience to development and its future inhabitants and the most efficient
use of land.
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Appendix 2
Tree Survey Schedule
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Tree Schedule Explanatory Notes
Tree ID Identifies trees, groups and hedges on the accompanying plan.
Common Name Common names of species are provided to aid wider comprehension.
Maturity Mature, Semi-mature, Young.
Likely Bat Habitat Whether the tree provides potential suitable bat habitat.
Measurements estimated Restricted access will result in measurements being estimated.
Height Describes the approximate height of the tree measured in metres from ground level.
Height and Direction of first significant branch
The height of first significant branch and compass direction.
Number of stems Number of stems
Stem diameter at 1.5m Stem diameter measured in accordance with BS5837:2012 in mm.
Crown Spread Indicates the crown radius from the base of the tree in four compass directions in metres.
Condition Condition of Crown, Stem and Basal Area. Characterised as Good, Poor and Fair.
BS Category B.S. Cat refers to (BS 5837:2012 Table 1) and refers to tree/overall group quality and value; 'A' - High; 'B' - Moderate; 'C' - Low; 'U' - Remove.
Life Expectancy Estimated remaining years categorised in year bands of <10, 10+, 20+, 40+.
BS Sub Category Sub Cat refers to the retention criteria values where 1 is arboricultural, 2 is landscape and 3 is cultural including conservational, historic and commemorative.
Physical Condition Overall condition of tree expressed as: Good, Fair, Poor, Decline, Dead.
Preliminary Tree Work Recommendations Tree works recommended following the tree survey in order to aid future inspections, remove any hazards or to enhance the trees future.
Tree
Ref.
No.
Species
(Common
Name)
Height
(m)N E S W
Grnd
Clrnc
DBH
(mm)
RPR
(cm)
RPA
(m)
Age
class
Gen
Cond
Structural
Defects/Comments
Estimated
remaining
contribution
(BS 5837)
BS CatBS Sub
Cat
Prelim Tree Work
Recommendations
T1 Oak 10 5 4 6 4 2 400 480 72.35 M G some major deadwood 40+ C 2remove major
deadwood
T2 Hawthorn 5 2 2 2 2 0 185 222 15.48 M G 40+ C 2
T3 Cherry 6 4 4 4 4 2 200 240 18.09 M Gextends over boundary
1m40+ C 2
T4Norway Spruce
'Glauca'5 2 2 1.5 1.5 0 200 240 18.09 S/M G 40+ C 2
T5 twisted willow 4.5 3 3 2.5 2.5 2 300 360 40.69 S/M P damage to stem <10 U 1 remove
T6 Oak 10 5 6 4 5 3 350 420 55.39 M G ivy in crown 40+ B 2 sever ivy
T7 Oak 11.00 4 7 4 5 3 400 480 72.35 O/M psevere chlorosis major
deadwood ivy in crown<10 U 3 remove
T8 Oak 10 4 4 4 5 2 350 420 55.39 M G ivy in crown 40+ C 2 remove ivy
T9 Oak 10 6 5 5 5 0 400 480 72.35 S/M G Ivy Covered 20-30 C 2
T10 field maple 10 3 3 3 3 2 180 216 14.65 M Gmulti stemmed tree in
good condition.40+ C 2
T11 oak 12 5 8 6 8 2 480 576 104.18 M G ivy covered 40+ B 2 remove ivy
Canopy Spread
Site:Hullbridge Client:Southern and Regional Developments Ltd Date: sep 2014 Job No: JBA10.252 Surveyed by: AT Tagged No. Weather Sunny
Tree
Ref.
No.
Species
(Common
Name)
Height
(m)N E S W
Grnd
Clrnc
DBH
(mm)
RPR
(cm)
RPA
(m)
Age
class
Gen
Cond
Structural
Defects/Comments
Estimated
remaining
contribution
(BS 5837)
BS CatBS Sub
Cat
Prelim Tree Work
Recommendations
Canopy Spread
Site:Hullbridge Client:Southern and Regional Developments Ltd Date: sep 2014 Job No: JBA10.252 Surveyed by: AT Tagged No. Weather Sunny
T12 Oak 10 4 4 4 4 3 380 456 65.29 M G 40+ B 2
T13 Oak 12 6 9 8 3 3 400 480 72.35 M G minor ivy on trunk 40+ B 2
T14 Norway maple 13 6 5 6 3 4 400 480 72.35 M G offsite 40+ C 2
T15 oak 10 8 5 6 8 2 400 480 72.35 O/M f
hole on eastern side with
severe decay in trunk
and branches
recommend bat
20-0 C 02-Mar
T16 Norway maple 9 6 7 5 5 2 300 360 40.69 M G 40+ C 2
T17 Norway maple 13 9 9 9 9 0 300 360 40.69 M G ivy covered 40+ C 2
T18 weeping willow 12 10 12 9 9 1 500 600 113.04 M F
large tree impeding other
treess in partial state of
collape
<10 U 2 remove
T19 Oak 9 7 7 7 7 2 300 360 40.69 M G 40+ C 2
T20 Oak 12 10 3 12 12 2 400 480 72.35 M G some major deadwood 40+ B 2
T21 Oak 10 5 7 7 7 4 450 540 91.56 M psubstantial damage to
western stem <10 U 3 remove
T22 Weeping Willow 9 5 5 5 5 0 380 456 65.29 M G >40 C 2
T23 Weeping Willow 9 5 5 5 5 1 300 360 40.69 M G >40 C 2
T24 Oak 10 7 7 7 7 2 400 480 72.35 M G 40+ B 2
Tree
Ref.
No.
Species
(Common
Name)
Height
(m)N E S W
Grnd
Clrnc
DBH
(mm)
RPR
(cm)
RPA
(m)
Age
class
Gen
Cond
Structural
Defects/Comments
Estimated
remaining
contribution
(BS 5837)
BS CatBS Sub
Cat
Prelim Tree Work
Recommendations
Canopy Spread
Site:Hullbridge Client:Southern and Regional Developments Ltd Date: sep 2014 Job No: JBA10.252 Surveyed by: AT Tagged No. Weather Sunny
T25 Oak 12 8 9 7 8 1 400 480 72.35 M G Deadwood 40+ C 2
T26 Oak 14 9 8 7 8 2 1200 1440 651.11 O/M F
Large cavity in base,
tree has high bat
potential
40+ C 2
T27 Oak 15 7 9 8 9 1 400 480 72.35 M F Multi stemmed 40+ C 2
T28 Oak 14 6 8 9 10 2 1000 1200 452.16 M FOffsite tree, large hole at
base, major deadwood40+ B 2
T29 Oak 14 7 6 6 5.5 4 380 456 65.29 M G minor ivy on trunk 40+ C 2
T30 Eucalyptus 16 7 7 7 7 4 400 480 72.35 M G
Climb and inspection
suggested for possible
decay issues.
40+ C 2
T31 Ash 16 9 9 9 9 4 400 480 72.35 M G
Climb and inspection
suggested for possible
decay issues.
40+ C 2
G1 Leyandii 7 3 3 3 3 0 300 360 40.69 M FBroken branches. Old
ash coppice40+ C 2
G2Ash Rowan
Hawthorn12 4 3 4 3 0 200 240 18.09 Y G
Broken branches. Old
ash coppice10-20 C 2 remove broken branch
G3Maple sycamore
leylandii7 3 3 3 3 0 200 240 18.09 M F group of trees off site 40+ C 2
G4hawthorn elm
holly5 2 2 2 2 0 175 210 13.85 M g
mixture of ornamental
trees and shrubs40+ C 2
G5Birch and norway
maple8 3 3 3 3 0 200 240 18.09 M F
mixture of ornamental
trees and shrubs40+ C 2
H1Elm, hawthorn
and elder2 1 1 1 1 0 175 210 13.85 M G Agricultural hedge 40+ C 2
Tree
Ref.
No.
Species
(Common
Name)
Height
(m)N E S W
Grnd
Clrnc
DBH
(mm)
RPR
(cm)
RPA
(m)
Age
class
Gen
Cond
Structural
Defects/Comments
Estimated
remaining
contribution
(BS 5837)
BS CatBS Sub
Cat
Prelim Tree Work
Recommendations
Canopy Spread
Site:Hullbridge Client:Southern and Regional Developments Ltd Date: sep 2014 Job No: JBA10.252 Surveyed by: AT Tagged No. Weather Sunny
H2hawthorn
blackthorn elm3 2 2 1.5 1.5 0 150 180 10.17 M G agricultural hedge 40+ B 1
bat survey, aerial h+s
survey
H3Blackthorn
hawthorn elm3 2 2 2 2 0 175 210 13.85 M G Agricultural hedge 40+ C 2
H4elm hawthorn
blackthorn4 2 2 2 2 0 200 240 18.09 M G Agricultural hedge 40+ C 2
H5elm hawthorn
blackthorn3.5 2 2 2 2 0 175 210 13.85 M G Agricultural hedge 40+ C 2
H6Blackthorn,
Hawthorn,4 2 2 2 2 0 200 240 18.09 M G Agricultural hedge 40+ C 2
- 13 - 13
Appendix 3
Tree Constraints Plan