Energise Galashiels – Hydropower Feasibility Study
February 2016
Document type: Report v3.0
Client: Energise Galashiels
Client contact: Ranald Boydell
Title: Energise Galashiels – Hydropower Feasibility Study
Date: 13/02/2016
Author: Euan Hogg
QA: Stan Johnston
Author contact details
Email: [email protected]
Telephone: 0131 202 1020
Contents
Executive Summary ...... 5
1. Introduction ...... 6 1.1 Background to the Project ...... 6 1.2 Scope of Report ...... 6 1.3 Hydro development in Scotland ...... 6
2. Constraints ...... 7 2.1 Flood Risk ...... 7 2.2 Water Resource ...... 7 2.3 Fish Protection ...... 7 2.4 Planning Requirements ...... 8
3. Site Development Potential ...... 9 3.1 Main Elements of a Hydropower Scheme ...... 9 3.2 Flow ...... 9 3.3 Head ...... 9 3.4 Turbine Types ...... 9 3.5 Turbine Selection ...... 10
4. Hydrological Assessment ...... 13 4.1 Legislative Background ...... 13 4.2 River Morphology ...... 13 4.3 Flow Assessment ...... 14 4.4 Power Generation Potential ...... 15
5. SEPA CAR Screening Checklist ...... 18 5.1 The Mill Lade ...... 18
6. Risks to the Water Environment & Mitigation Measures ...... 20 6.1 Typical Construction Method Statement ...... 21
7. Site visits and Site Descriptions ...... 24 7.1 Site Visits ...... 24 7.2 The Mill Lade ...... 24 7.3 The Gala Water ...... 39 7.4 The Buckholm Lade ...... 43
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8. Structural Engineering Survey of the Mill Lade ...... 45 8.1 Introduction and Purpose ...... 45 8.2 Town Mill Lade Background ...... 45 8.3 Summary of Findings and Remedial Works Required ...... 46 8.4 Description of Defects and Recommended Actions ...... 46 8.5 Cost Estimates ...... 49 8.6 Buckholm Lade Cost Estimate ...... 50 8.7 Summary and Conclusions ...... 50
9. Economic Evaluation ...... 51 9.1 Electricity connection ...... 51 9.2 Operational Costs ...... 51 9.3 Income ...... 51 9.4 Financial Returns – Mill Lade ...... 52 9.5 Financial Returns – Gala Water ...... 53 9.6 Financial Returns – Buckholm Lade ...... 54
Appendix 1 – Detailed Descriptions of the Lade by Chainage ...... 55
Appendix 2 – Town Lade Refurbishment Costings ...... 63 Galashiels Town Lade Refurbishment ...... 63 Buckholm Lade Refurbishment ...... 64
Appendix 3 – Hydro Power Systems Costings ...... 66
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Executive Summary
Scotland & the UK is seeing a rise in the number of small scale hydro electric projects being implemented which are being driven by the following factors:
1) In May 2011, the Scottish Government’s 2020 renewable electricity target was raised to 100%; 2) The Feed-In-Tariff (FITs) scheme was introduced on 1 April 2010. The aim of this was to encourage small-scale (under 5MW) low-carbon energy generation particularly by groups such as communities, businesses and individuals not normally engaged in the electricity market, and
The Borders is a region that was built on its water courses and much of the infrastructure used to power the textiles industry still remains but has fallen into disrepair. The Energise Galashiels Community Group was established to harness the natural resources that surround the town as a source of renewable energy. As part of a success Local Energy Scotland Challenge Fund application, the Community Group was awarded grant funding to undertake a feasibility study of the hydropower potential of the community.
The focus of the Group has been on re-establishing the town lade which runs through the Town Centre and offers of a number of potential micro hydropower sites utilising existing wheel pits. Investigation into re-establishing of the Buckholm Lade which runs to the north west of the town has also been considered. Finally the Gala Water, which runs through the centre of the town has also been considered for hydropower development.
The Energise Galashiels Community Group will use the findings from this feasibility study to submit a Local Energy Scotland Challenge Fund Phase 2 application in February 2016.
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1. Introduction
1.1 Background to the Project This report results from an instruction from the Energise Galashiels Community group to provide a feasibility appraisal of potential small hydro power sites along the Galashiels Mill Lade and the Gala Water as part of their objective for the community to be able to generate and use renewable energy for their long term and collective benefit.
The purpose of the study is to support the Energise Galashiels Community group with a source of site-specific information on hydropower development.
1.2 Scope of Report The location of a number of potential sites has been identified, and preliminary calculations completed to give a guide to their viability for development. The scope of this report is therefore limited to:
• Site identification; • Hydrology; • Power generation; • Land ownership; • Planning & environmental issues; and • Grid connection issues.
It is envisaged that following review of this report the above issues can be addressed in a Feasibility Report for the selected sites.
1.3 Hydro development in Scotland The first hydropower plant for public supply in Scotland was in 1885 in Greenock, Renfrewshire, followed in 1890 by an 18kW scheme constructed by monks at St. Benedicts’s Abbey at Fort Augustus, both serving to demonstrate the resource potential and technical feasibility. The development of hydropower on a national scale following in the 20th Century, with an initial phase of private development supporting the aluminium smelting industry in the 1920’s, then the most significant expansion of hydropower in the 1950’s and 1960’s under the North of Scotland Hydro-Electricity Board (NoSHEB). In the fifteen year period from 1950 to 1965, 74 hydropower installations were constructed totalling over 950MW in capacity.
With the increase in Greenhouse Gas (GHG) emissions from finite fossil fuels contributing to Climate Change, hydropower in Scotland over the last 25 years has undergone further expansion and an increased profile as a source of renewable energy under the climate agenda. With 3.3TWh in production and 1.4GW in installed capacity in 2010, as a contribution of total national electricity generation, Scotland is in the top ten hydropower countries worldwide.
Hydropower in Scotland accounts for 34% of all renewable electricity generation and 7% of total generation in 2010. Scotland is also the principle generator of hydropower in the UK, supplying over 90% of 2010 production.
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2. Constraints
Hydropower is supported in principle. However, each potential site must consider a number of factors for which the Scottish Environment Protection Agency (SEPA) has statutory responsibility, namely flood risk, water resources, pollution and fish protection.
2.1 Flood Risk All eight sites considered within this report are in areas of a 5% flood risk (i.e. floods are likely to occur five times in every hundred years). Proposals for each site must convince SEPA that they do not add to the flood risk. Hydro sites may either be placed alongside a river and not within the river bed (Water Engines), or be within the river bed (Archimedes Screw). Therefore, the power house, turbine and associated water channels must be shown not to increase the flood risk. Generally speaking, the small size of power house that is required for a Water Engine will not constitute any increase in flood risk, more especially so when it is above and outside the river bed. In the case of an Archimedes Screw, the potential for increase in flood risk is greater but this should be capable of being mitigated by careful design. Clearly, consideration must be given to the siting of the electrical control equipment inside the power house to avoid the risk of flood damage.
2.2 Water Resource A hydro system that takes water from the water course (Water Engine) must obtain an Abstraction license from SEPA. Under the Water Resources (Abstraction and Impounding) Regulations 2006, a water abstraction license will be required from SEPA for schemes which abstract water and then return it to the watercourse. The Abstraction license is Legal permissions to remove a certain amount of water from the river in order to operate a hydro plant. Such licenses are given for a period of up to 10 years and are subject to renewal after that period. Licenses are given ‘with the presumption’ of renewal’. The license will also indicate the amount of water that is required to be left in the river. This is usually the Q95 level (the flow exceeded 95% of the time). If there is a weir, this must be kept wet to help its structural stability, to assist with fish passage and for the aesthetics of the weir. It can take up to 4 months to obtain an abstraction license and SEPA may require supporting reports – particularly for the environment and the effect on the fish – in order to agree with the license.
Where an existing weir is intended for use with an Archimedes screw type of system, an abstraction licence will not be required, but the complications associated with locating the screw onto the weir can bring even greater licencing and approval issues.
2.3 Fish Protection SEPA has a statutory duty to protect fish. In order to progress projects in the Galashiels area, SEPA will require information on how important the watercourses involved are to fish and fisheries at a local, regional, catchment, national or international level. Details including the locations of the present upstream limits of salmon, sea trout, eels, lamprey, spawning river trout or loch trout within the watercourse. The River Tweed Commissioners will be able to provide detailed information on the watercourses in question.
An assessment of the suitability for fish in the river habitat between the upstream end of the impound river flow and the scheme outfall. The level of detail required will depend on the relative risk of the scheme.
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2.4 Planning Requirements Any hydro site within the scope of this report will require planning consent. This normally takes two months from the point of ‘validation’. Each scheme will need a Detailed Scheme Design drawing up which would form the basis of the planning application. There are now national guidelines concerning planning consent and the validation requirements. In order for a planning application to be ‘validated’ the application would need to supply a number of plans and reports, specifically:
1. Site plan, Location plan, Block plan and elevations. These will be required at given scales, the details of which need to be sought from the planning officer prior to submitting an application;
2. In addition, each application will be a Design and Access Statement and, depending on the site, an environmental report, economic statement and statement of community involvement. The number of supplementary reports are site specific and an early meeting with planning officers is necessary to ascertain exactly which reports will be required.
The Climate Change Act of 2008 has established compliance and accountability procedures for meeting Government targets on carbon emissions. These targets will be legally binding and Local Authorities will play a role in meeting and monitoring the targets. Failure to reach targets will mean penalties in central government funding.
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3. Site Development Potential
3.1 Main Elements of a Hydropower Scheme
All hydropower schemes depend first and foremost on determining the viability of a particular site. Fundamentally the two primary requirements are a readily available fluid flow, in combination with an adequate vertical change in elevation, referred to as ‘gross head’. The hydraulic power available at a particular site is proportional to the product of flow and head (Power = flow x head). Traditional hydropower technologies generally rely on a waterfall or a weir structure within a water course as a promising starting point for hydropower feasibility studies.
3.2 Flow
The flow rate within a water course can vary considerably depending on the frequency, intensity and volume of rainfall, as well as the catchment characteristics, such as size, topography and ground porosity.
The variance in watercourse flow, in combination with the performance characteristic of the hydro generator, affects the annual energy production of a scheme. Further constraints such as ‘hands-off flow’ (the minimum flow to be left in the depleted reach of the water course) which serves to protect the ecology of the local environment.
3.3 Head
Whereas ‘gross head’ refers to the difference in elevation between the intake and the outfall, the ‘net head’ refers to the head directly across the generator.
The vertical head difference may be the operational head on some machines where there is little or no conveyance channel or pipe between the abstraction and return points to the water. More typically however there will be a channel or pipe between these two points. Friction between the flow water and the walls of the channel or pipeline result in a loss of head.
3.4 Turbine Types
As water passes through a hydraulic turbine, hydraulic power is transferred to shaft power by a prime mover, commonly referred to as a ‘runner’. The runner can incorporate blades, vanes or buckets, which are forced to rotate around a central axis. The runner shaft is coupled to a generator which converts shaft power to electrical power. There are a number of different designs of commercially available turbines, each with varying geometry and performance.
It is a well-established convention to group these turbines in two main categories:
• Impulse turbines; and • Reaction turbines.
Impulse turbines have no change in static pressure across the runner. It is also a common feature of reaction turbine runners to be wholly immersed in the fluid flow, as opposed to an impulse turbine where a jet of fluid strikes the runner. There are a number of turbine designs that do not fit comfortably within these categories.
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3.5 Turbine Selection
All hydropower turbines have unique characteristics equating to the variance in efficiency of the machine when operating under different head and flow conditions. Selecting the optimum turbine type and power capacity for a specific site is an extensive process. A complete evaluation would require determination of the capital costs, operational costs and borrowing costs associated with each turbine type.
At this stage of the project, a simpler approach is taken to establish a good solution without incurring large design requirements. This approach is as follows:
1. The intake and outfall positions on the watercourse are selected using hydropower experience to predict a suitable trade-off between maximising gross head across the scheme and avoiding undue capital costs. There are also additional costs including dealing with multiple landowners, working in sensitive habitats and completing construction works within a short permitted in-river works period.
2. Plant power capacity is maximised by selecting the maximum design flow rate that can be expected to be licenced by the statutory consultees. This serves to exploit the well-established rule that larger schemes benefit from scales of economy.
3. Once the head and design flow rate have been determined, the most suitable turbine type with the most applicable efficiency characteristics under the site conditions. The turbine type that proves the most energy is selected as the basis for the average annual revenue and capital cost estimates.
Table 3.1 – Hydropower turbine types
Type Description
Pelton Wheel Impulse turbine named after early developer, Lester Pelton. Utilises one or more high velocity jets directed tangentially onto runner buckets.
Turgo Impulse turbine that utilises high velocity jets imparted at an angle to the face to the runner. In comparison to the Pelton Wheel, this orientation allows for a larger jet and higher rotary speed; however efficiency is reduced.
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Cross-flow Impulse turbine, also known as a Banki or Michell turbine, where the water jet crosses through the runner vanes twice. A draft tube creates sub-atmospheric pressure in the runner housing. The cross-flow can achieve higher running speeds than other impulse type turbines.
Francis Mixed-flow reaction turbine with flow entering the runner in the radial direction and leaving in the axial direction.
Propeller Axial-flow reaction machine with fixed runner blades.
Kaplan Axial-flow reaction machine with adjustable runner blades and fixed guide vanes allowing improvement of part-flow efficiency.
Semi-Kaplan Axial-flow reaction machine with adjustable runner blades and fixed guide vanes.
Archimedes Screw Turbine which turns slowly and generally requires addition of a gearbox to increase generator shaft speed.
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Water Wheel Classical design developed from early industrial application and generally requires the addition of a gearbox to increase the generator shaft speed.
Water Engine Fish-friendly low head hydropower system that generates high pressure hydraulic fluid to drive a gear motor.
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4. Hydrological Assessment
4.1 Legislative Background
The Water Environment and Water Services (Scotland) Act 2003
The Water Environment and Water Services (Scotland) Act 2003 (WEWS) is the enabling act within Scotland for the Water Framework Directive 2003 (WFD). As stated on SEPA’s website, WEWS gave Scottish ministers powers to introduce regulatory controls over water activities, in order to protect, improve and promote sustainable use of Scotland’s water environment. This includes wetlands, rivers, lochs, transitional waters (estuaries), coastal waters and groundwater.
The Water Environment (Controlled Activities) (Scotland) Regulations 2011 (CAR)
CAR established the authorisation regime for regulating activities which may affect Scotland’s water environment. CAR is a secondary piece of legislation introduced once WEWS has been passed which enables SEPA to regulate discharges, disposal to land, abstractions, impoundments and engineering works through licensing. Hydroelectric schemes are therefore regulated under CAR with schemes of installed capacity ≤ 100kW requiring a simple licence.
4.2 River Morphology
The Gala Water catchment area was observed to be mainly impervious from the Silurian geological period. The maximum altitude of the catchment is 651mAOD with a minimum of 120mAOD. The upland catchment mainly drains from Moorfoot Hills. In the surrounding area there is mainly hill grazing with some arable land.
Figure 4.1- Gala Water Catchment Area
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4.3 Flow Assessment
Water Engine Technologies undertook a hydrological assessment of the Gala Water which produced a Flow Duration Curve (FDC) for the Gala Water at the proposed intake location as shown in Figure 4.1.
Figure 4.2 – Gala Water Flow Duration Curve
Design flows are generally based upon an estimate of mean flow predicted in the watercourse. Depending upon the sensitivity of the watercourse, there may be scope to base the design flow of the scheme on 100%,
120% or 150% of mean flow. In terms of an FDC, these values generally equate to Q30, Q25 and Q20 (the flow that is exceeded 30%, 25% and 20% of the time) respectively. Compensation flows (assumed to be Q95 in this case) are subtracted from each of these to derive design flows for the scheme
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Table 4.1 – Key flows from Flow Duration Curve
Exceedance Flow rate Percentile (%) (m3/s)
Q20 5.43
Q25 4.56
Q30 3.95
Q80 0.96
Q90 0.67
Q95 0.53
4.4 Power Generation Potential
Potential power generation calculations have been undertaken allowing for practicable mitigation measures likely to be required by SEPA. These measures are summarised in table 4.2.
Table 4.2 – SEPA Hydropower Scheme Mitigation Measures
Purpose Mitigation (summarised)
Protection of low No abstraction at or below hands-off flow. flows 2 • Upstream catchment area <10km – Hands-off flow Qn90 2 • Upstream catchment area >10km – Hands-off flow Qn95
Protection of flow When flow upstream of intake would be Qn30, flow downstream should be variability Qn80
Protection of high • For schemes with annual output <0.35 GWh, maximum allowable flows abstraction likely to be 1.3x Average Daily Flow (ADF) • For schemes with annual output >0.35 GWh, maximum allowable abstraction likely to be 1.5x Average Daily Flow (ADF)
Other factors influence the allowable abstraction regime so Table 4.3 is intended to provide guide only as to the likely allowable abstraction regime.
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Table 4.3 – Mitigation Parameters Summary
ADF 3.74m3/s
Upstream catchment area 207km2
3 Flow thresholds Qn95 (hands-off flow) 0.53 m /s 3 Qn80 (compensation flow when river flow at Qn30) 0.96 m /s 3 Qn30 3.95 m /s
Potential annual output ≥ 0.35 GWh
Abstraction scenarios ADF 3.74 m3/s 1.3x ADF 4.86 m3/s 1.5x ADF 5.61 m3/s
Table 4.4 – Potential Abstraction Regime
Flow rate Natural (m3/s) Maximum available for Residual (m3/s) Abstraction (m3/s)
1.5x ADF 1.3x ADF 1.5x ADF 1.3x ADF
Qs 21.33 5.61 4.86 15.72 16.47
Q10 8.28 5.61 4.86 2.67 3.42
Q20 5.43 4.47 0.96
Q30 3.95 2.99 0.96
ADF 3.74 2.78 0.96
Q40 3.00 2.47 0.53
Q50 2.33 1.8 0.53
Q60 1.81 1.28 0.53
Q70 1.35 0.82 0.53
Q80 0.96 0.43 0.53
Q90 0.67 0.14 0.53
Q95 0.53 0 0.53
The maximum allowable abstraction is indicated to be 5.61 m3 /s and the associated maximum power output is as shown in Table 4.5. The annual power output has been predicted on the basis of the capacity of the scheme throughout the year, with two adjustments to ensure that the estimates are realistic. The capacity factor, however, should be confirmed through further analysis. Post‐construction of the proposed scheme, it is envisaged that maintenance requirements may require the scheme to be offline for approximately 1 week annually.
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While a maximum abstraction of 1.5x ADF is likely to be acceptable to SEPA, in practice 1.3x ADF is considered to be a more realistic and more frequently achieved maximum abstraction flow. The maximum allowable abstraction on this basis is indicated to be 4.86 m3 /s
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5. SEPA CAR Screening Checklist
5.1 The Mill Lade According to Guidance for developers of run-of-river hydropower schemes Part A Table 1, the proposed scheme, which produces >0.35 GWh, satisfies the following requirements:
• Satisfy the criteria described in the checklists in Annex A; • Incorporate the mitigation described in Part B (compensation flow); and • Not cause significant adverse effects on the interests of other users of the water environment.
On the basis that the proposed abstraction rates will be appropriately sized to avoid significant deterioration in terms of waterbody status, it is considered likely that the scheme is provisionally acceptable to SEPA.
Table 5.1 – SEPA Checklist D: All Other Proposals
No. Criterion Energise Gala Action if Yes Action if No Mill Lade
1 Will the scheme be powered by the flow of water through an No Provisionally Go to 2 existing weir or dam (i.e. without removing water from the acceptable river channel
2 Will the scheme be powered by water flow from an existing No Provisionally Go to 3 outflow? acceptable
3 Will the scheme be powered by water that is abstracted from No Provisionally Go to 4 immediately above a drop (e.g. a waterfall, cascade or weir) acceptable and returned below that drop?
4 Is the proposal located on a minor tributary of a water body No Go to 7 Go to 5 (i.e. a tributary with a catchment area of <10km2)?
5 Is the water body at high status? No Go to 7 Got to 6
6 Is the distance between the intake and the tailrace (excluding No Go to 7 Go to 7 any part of that distance that is on a minor tributary) together with any reaches impacted by other activities < 500 metres?
7 Will the scheme use only the proportion of the flow in the river Yes Provisionally Provisionally or stream at any one point in time that can be abstracted acceptable. unacceptable without causing a breach of the river flow standards for good if annual (note 2)? output is <0.35 GWh.
The checklists form a CAR screening document which was submitted to SEPA’s virtual permitting team for an initial opinion regarding scheme viability under the CAR Regulations. SEPA confirmed that the scheme is potentially acceptable provided that river flow standards for Moderate are not breached by abstraction.
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Table 5.2 – SEPA Checklist D: All Other Proposals
Flow range Allowable Abstraction for Moderate Standards
Flows ≥ Qn60 55%
Flows Flows Flows 19 Energise Galashiels – Hydropower Feasibility Study 6. Risks to the Water Environment & Mitigation Measures The construction works that require to be undertaken for the Energise Galashiels Scheme have the potential to cause pollution or impact on the bed and banks of the watercourse and on the quality and quantity of the water. These works will be authorised through a simple licence under CAR, which places a legal responsibility on the responsible person to ensure that works are taken out as documented and all reasonable measures are undertaken to prevent adverse impact to the watercourse. The main impacts to the water environment that could occur due to construction activities are: • Production of silt or fine sediment; • Oil or fuel spillages; and • Pollution due to concrete/cement. The route of the access tracks are not yet known. Once the detailed design of the scheme and access routes are known, any potential effects can be assessed. The main risk to the water environment during operation of the hydro scheme is the reduction in flows in the affected reach of the Gala Water. This effect on the water environment has been minimised through design including allowable abstraction flows described in the previous section and is not considered to be significant. The works will be carried out in accordance with the general best practice guidelines set out in Pollution Prevention Guidelines and by SEPA & SNH: • PPG 1 General guide to the prevention of pollution; • PPG 5 Works and maintenance in or near water; • PPG 6 Working at construction and demolition sites; • PPG 7 Refuelling facilities; • PPG 26 Drums and intermediate bulk containers; • SEPA Technical Guidance Note – On‐site management of Japanese Knotweed and associated contaminated soils; • SNH best practice will be followed on site during construction, for example covering holes/placing escape ramps and sealing pipes at the end of each day; and • Any conditions accompanying the CAR licence. Construction activities will be managed under a Construction Environmental Management Plan (CEMP) and overseen by an Ecological Clerk of Works (ECoW).The site specific mitigation measures that will be included within the proposed works to reduce the potential pollution risks from each of the above sources are detailed in Table 6.1. A surface water cut off ditch will be constructed around the site compound to prevent any clean water flowing across the site. Welfare facilities will include a chemical toilet/portaloo which will be routinely serviced to remove sewage offsite. Site water supply will be via a trailer bowser and bottled water made available. 20 Energise Galashiels – Hydropower Feasibility Study Table 6.1 – Sources of Risk and Mitigation Measures Source of Risk Mitigation Measures Site or fine sediment entering the • The majority of the works to be constructed in dry conditions watercourse: Generated by surface away from flowing water. water runoff from working area. Results • The areas of topsoil strip to be progressive, reducing the relative in: area and times of disturbed ground exposed through the duration of the works. • Discolouration • Formation of tracks to include suitable cambers and cross‐drains • Increased sediment load to ensure they do not form drainage channels. • Downstream disposition of • Excavation activities will replace pre‐existing turf as part of fines restoration, minimising any areas of exposed soil. • Local impact on aquatic ecology • All the works will be supervised by personnel experienced in due to reduction of light in working within rivers and having been involved in similar works water and disposition on bed over recent years. Oil or fuel spillage: • All fuel storage on site to be bunded, placed on an impermeable Storage and refueling activities. surface and be compliant with the Water Environment (Oil Storage) (Scotland) Regulations 2006. Plant working near watercourses. • All fuel to be stored at least 10m away from watercourses. • All refueling of plant to be undertaken at least 10m away from the burn using a drip tray with suitable capacity asset out in PPG26. • A spill kit to be available for plant on site. • All plant to be inspected to ensure that they are clean with no leaks. Concrete/cement: • All concrete pours to be undertaken in dry conditions where Construction of intakes, header pond possible. tailrace channel and power house • All formwork to be tightly sealed and tested to prevent leakage. • Relatively small quantities of concrete used. • Bulk of concrete used in areas where no surface water drains are present. Successful implementation of the mitigation measures will reduce the risk of pollution to the Gala Water as a result of the site works. All of the recommended mitigation measures asset out in Table 6.1 will be monitored as part of the supervision of the overall works, which will be undertaken by the contractor. Should any pollution incidents occur as a result of the site activities, SEPA will be contacted and appropriate mitigations implemented. 6.1 Typical Construction Method Statement The following is a typical method statement for the construction of a hydro-power system. Some of the following sections may not be applicable to a specific project: Access Tracks The main site access will be clearly marked as a construction access point. New tracks will be formed above the pipeline routes, which will be reinstated to a narrow width capable of being used by a small all‐terrain 21 Energise Galashiels – Hydropower Feasibility Study vehicle, such as a quad bike. When developing the access tracks, a formal drainage system will be formed, including ditches, camber to shed water to the edges, frequent cross drains and trackside grips/offlets to prevent the tracks acting as a preferential drainage route and to protect the water environment. Any trackside discharge should pass through a silt trap or other similar measure in line with Sustainable Drainage System (SuDS) principles and spread over a buffer area before flowing into a defined watercourse. Water should not be allowed or encouraged to pond in the road where possible. Water Intake The area of the bed where the intake will be constructed will be worked in the dry. A temporary cofferdam will be formed around the works area using either native material or sand bags. The water will then be diverted around the works, by pumping. Any material placed within the channel during the construction of the temporary works will be removed as soon as its function has been fulfilled in a manner which minimises pollution. Concrete Works For the works that require concrete (primary intake) concrete will be pre‐mixed off site and transported dry to the works area where water will be added to the pre‐mix and the concrete mixed close to the point of use. Concrete at the turbine house will be delivered as ready mix and poured for large volumes, with blockwork mortar being mixed as required on site. The concrete works will be poured into dry workings and the formwork will be tightly sealed to ensure that there are no concrete leaks to the water environment. All washing of equipment shall be undertaken in a closed system and any discharge of washings must be to land at a distance greater than 10m from any open water. Once settled, the clean water from concrete washings will be pumped out to the wider area within the watercourse and the residual material will be excavated and removed from the hill by dumper. Pipework The excavations from the pipeline will be placed temporarily on the downslope while the pipe trench is prepared to place the pipe. They will be sealed as soon as practical after deposition and until re‐use for infilling to ensure quick stabilisation. The excavated turf will be placed on the top side of the excavation for use as reinstatement and used to reinstate the downslope of the reinstated track over the pipeline. The infill material will only use inert and non‐toxic material, preferably the initial material. Directional drilling maybe employed where possible and appropriate for deeper sections of the penstock. The pipeline will be prevented from acting as a drainage conduit when open by having regular offlet drains leading from it to allow water to be attenuated and pumped out as necessary. Tailrace A tailrace will be formed between the discharge from the turbine at the powerhouse and the final discharge back to the Gala Water. The tailrace downstream will be an open ditch. The line of the ditch and area for placement of arisings will be stripped and the turf set aside for use in restoration. The ditch will be excavated, 22 Energise Galashiels – Hydropower Feasibility Study the arisings landscaped nearby and the turf reinstated to the banks of the ditch. At the discharge point, a 20mm fish screen will be constructed as per the CAR requirements. Refuelling All refuelling and maintenance of plant and machinery to be carried out in line with PPG7 and PPG26. The main refuelling point will be at the site compound. Fuel deliveries will fill portable bunded bowsers at the compound on a designated impermeable and bunded area. Machinery will be refuelled from the compound where possible. Fuel will be transported to where the machines are working by a suitable vehicle such as a tracked dumper. Refuelling from the portable bowser to individual machines will use drip trays and have spill kits available with each machine, and be at least 10m away from any open watercourse. All machinery used on site shall be regularly maintained and inspected for leaks. Any leaks identified must be stopped, contained and repaired. In the event of an accidental spillage of any polluting substance or the pollution of the water environment, the contractor will immediately notify the Project Manager and thereafter SEPA. Any works directly associated with the cause of the incident will be halted, the effects mitigated where possible and measures put in place to prevent recurrence. 23 Energise Galashiels – Hydropower Feasibility Study 7. Site visits and Site Descriptions 7.1 Site Visits Each of the sites was assessed according to a number of criteria. The criteria were applied to each of the sites visited. 1. Site access – any potential site must be capable of being accessed by construction traffic and be capable of allowing delivery of the hydropower unit itself. In addition, there must be sufficient space adjacent to the watercourse to allow temporary construction site. An additional factor is the proximity of the nearest electrical substation/three phase supply. 2. Cost and ease of construction 3. Potential power output – dependent upon the height and flow of the river. 7.2 The Mill Lade The Galashiels Mill Lade runs through the length of the town from an inlet point at the upstream end that is presently controlled by manual sluice gates. The lade can be considered in three sections, being the upper third, which runs from the inlet point beneath the railway bridge, to the point at which the Lint Burn joins with the lade; the middle third that runs from the Lint Burn to the Moss Burn inlet at the Fountain; and the lower third that runs from the Fountain to the discharge point south east of the town. The middle and lower thirds of the lade are active water courses and deal with the flows from the two burns. The integrity of the water course in these sections is significantly better than the upper third, which is largely disused and is in need of significant upgrade. When the lade was in use, it had a series of turbines drawing power from a series of drops in the water course. Whilst all of these turbines have now been removed, leaving only a few memorials to their former importance, the drops in the lade remain largely intact though disused. In several cases, the original drops appear to have been lost through recent redevelopments, but even in these cases the lade still has a fall that can be utilised through the creation of new infrastructure alongside the lade. The upper third of the lade is now largely disused, though a small trickle of water is allowed to pass through it down to the point at which the Lint Burn joins the watercourse. In addition to the inlet water, a small amount of surface water drainage enters the lade at numerous points, such that the total flow in the lade increases as it travels towards the outlet point. Many parts of the upper third are in poor condition and significant work will be required to return this section to an operational condition. 24 Energise Galashiels – Hydropower Feasibility Study 7.2.1 Geographical Data Geographical data Value Bed level at inlet to lade at point A 118.87m Bed level at inlet to lade at point B 97.71m Approximate total drop 20m Length of lade 3km Overall average gradient 1:150 7.2.2 Flow Rates The currently accepted flow rate in the lade is 2 million gallons per day, which equates to about 0.1m3/s. This flow rate is totally inadequate for powering low head hydro systems of any type. The maximum expected output from this flow would be only about 1 – 2 kWs. The peak flow that the lade could ever have been expected to carry is, however, as high as 11m3/s in severe flood conditions. To this figure must be added an allowance for surface water drainage into the lade, estimated to be about 0.1m3/s per kilometre run of lade (total length = 3km = 0.3m3/s). The peak flow from the Lint Burn has been estimated at 1.5m3/s. The peak flow from the Moss Burn has been estimated at 8.13m3/s The total peak outflow from the Town Lade is therefore 21m3/s The cost of restoring the lade structures was estimated in 1986 to be of the order of £250,000. We would suggest this figure could be expected to stand at about £0.5m at current prices, given the redevelopment work that has taken place over much of the lade’s length in the 30 years since the estimate was prepared. Whilst we could not countenance using anything like the above-noted figures as being representative of the flow that could, or should, be maintained in the lade we consider the following flow values to be safe estimates of what could be sustained: Sites 1 – 3: 1.0 m3/s Sites 4 – 6 1.2 m3/s Sites 7 – 11 1.5 m3/s It should be noted that these figures are simply an estimate of what would seem to be a safe flow along the lade, providing a steady output from the Water engines. It should be noted that any water diverted through the town lade will represent an abstraction from the Gala Water, thus creating a “dewatered reach” downstream from the inlet to the lade all the way to Netherdale where the lade re-joins the river. Any such abstraction will require a licence from SEPA and will require the approval of planning, and the other stakeholders (see section 4). Under flood conditions, it may be necessary to allow increased flows along the 25 Energise Galashiels – Hydropower Feasibility Study lade, which would require the engines to begin to operate in sluicing mode to allow excess water to pass through. A system of water level controls will be required to act upon the main intake sluice gates and to control the flow through each engine. 26 Energise Galashiels – Hydropower Feasibility Study 27 Energise Galashiels – Hydropower Feasibility Study 7.2.3 Site 1 – Galabank Mill Location in car parking area behind Jewsons. This site includes an original wheel pit with a drop of about 1.0m. There is adjacent land that could be used for a Water Engine with piped inlet & outlet. Figure 7.1 - Queen Street and Wilderhaugh Street, Galabank Business Park, near Limelight Childcare Adjacent industrial and commercial buildings could be used to connect to grid. This site is deemed practicable. Figure 7.2 – Galabank Mill inspection Hydro power potential: 1.0m3/s @ 1.0m head = 10kw inlet = 7kw Output Figure 7.3 – Galabank Mill former wheel pit location 28 Energise Galashiels – Hydropower Feasibility Study 7.2.4 Site 2 – Wilderhaugh Mill Location outside McDonalds. This site includes a wheel pit and tail race with a drop of about 1.0m, though this infrastructure is now beneath a car parking area. Figure 7.4 - Wilderhaugh Street, near McDonalds There is adjacent land that could be used for a Water Engine with piped inlet & outlet. Adjacent industrial and commercial buildings could be used to connect to grid. Figure 7.5 – Wilderhaugh Mill inspection This site is deemed practicable. Hydro power potential: 1.0m3/s @ 1.0m head = 10kw inlet = 7kw Output. Figure 7.6 – Wilderhaugh Mill location 29 Energise Galashiels – Hydropower Feasibility Study 7.2.5 Site 3 – Rosebank Mill Location beside Car Parts for U where lade crosses under road. This site is covered by a steel plate and has not been visually assessed. The drop is shown on C&H drg no. 4138-401 as being about 0.8m. Figure 7.7 - Hall Street and Roxburgh Street, near Car Parts 4 U There is adjacent land that could be used for a Water Engine with piped inlet & outlet. Adjacent industrial and commercial buildings could be used to connect to grid. Figure 7.8 – Rosebank Mill inspection This site is deemed practicable. Hydro power potential: 1.0m3/s @ 0.8m head = 8kw inlet = 6kw Output Figure 7.9 – Rosebank Mill Location 30 Energise Galashiels – Hydropower Feasibility Study 7.2.6 Site 4 – Botany Mill This site is now entirely underground beneath yard and car parking area. Limited visual inspection was carried out via a steel access plate that was lifted for the inspection. Figure 7.10 - Roxburgh Street, within yard of vacant buildings It appears that the original turbine pit is no longer extant, but there is still a discernible drop through the lade below ground. C&H drawing 402 shows a gradual fall of about 1.3m within the old SSEB yard. Figure 7.11 – Botany Mill Inspection Hydro power potential: 1.0m3/s @ 1.3m head = 13kw inlet = 9kw Output Figure 7.12 – Botany Mill Location 31 Energise Galashiels – Hydropower Feasibility Study 7.2.7 Site 5 – Waukmill Head Figure 7.13 - Bank Street, underneath various shops/offices This site is beneath various commercial and residential properties. There is no evidence of any useable drop This site is deemed impracticable 32 Energise Galashiels – Hydropower Feasibility Study 7.2.8 Site 6 – Cornmill (The Fountain) This site is located in the centre of Galashiels and is a listed feature. A drop of about 1.5m exists at this site, but there is no space to locate a Water Engine, except within the fountain itself. Planning permission for such an installation is highly unlikely due to the visual intrusion of the headworks above parapet level. It may, Figure 7.14 - Bank Street, the cornmill fountain however, be feasible to install a small Archimedes Screw in this location if planning approvals can be obtained. It is also considered feasible to install a small demonstration Water Engine into this site, which would be a temporary installation with minimal impact on the fabric of the Fountain. Such an installation would likely be a very good means of allowing the community and the regulators / stakeholders to see how hydro power could Figure 7.15 - Cornmill Inspection be brought back to Galashiels without causing unacceptable impacts. It is considered feasible to install an Archimedes screw turbine into the bottom chamber of the Fountain as a permanent installation with limited impact on the existing fabric. Such an installation could be contained within the below-ground Figure 7.16 - Cornmill Location extent of the fountain structure and would have minimal visual impact. Hydro power potential: 1.5m3/s @ 1.5m head = 23kw inlet = 15kw Output 33 Energise Galashiels – Hydropower Feasibility Study 7.2.9 Site 7 – Midmill This site is located in the corner of Tesco car park. This site includes a wheel pit with a drop of about 2.0m. There is adjacent land that could be used for a Water Engine with piped inlet & outlet. Figure 7.17 - Paton Street, in corner of Tesco car park Adjacent Tesco supermarket could be used to connect to grid. This site is deemed practicable. Hydro power potential: 1.5m3/s @ 2.0m head = 30kw inlet = 20kw Output Figure 7.19 – Midmill Inspection Figure 7.18 – Midmill location 34 Energise Galashiels – Hydropower Feasibility Study 7.2.10 Site 8 – Woollen Factory This site is now incorporated into the car park for the retail units. Whilst a redundant turbine is displayed on the site, there is no evidence of the wheel pit remaining. Figure 7.20 - Huddersfield Street, within Gala Water Retail Park care park, western section Despite the likely unavailability of the drop at the wheel pit for this site, there remains the gradual fall of the lade as it runs through the present retail park car park. It would be feasible to install a Water Engine using a piped inlet/outlet connected to the original lade underground. Hydro power potential: 1.5m3/s @ 0.5m head = 7.5kw inlet = 5kw Output Figure 7.21 – Woollen Factory Inspection 35 Energise Galashiels – Hydropower Feasibility Study 7.2.11 Site 9 - Huddersfield Mill Figure 7.22 - Huddersfield Street, within Gala Water Retail Park care park, eastern section This site is very similar to Site 8 above, and is also located beneath the car park of the retail park. It is also likely that the original drop on this site has been lost, but it would, again, be feasible to use a piped Water Engine alongside the gradual fall of the lade. Hydro power potential: 1.5m3/s @ 1.2m head = 18kw inlet = 12kw Output 36 Energise Galashiels – Hydropower Feasibility Study 7.2.12 Site 10 – Gala Mill This site is located in the middle of the Schofield’s yard. This site includes a wheel pit with a drop of about 2.0m, though the pit has been used for various purposes and has steam pipes, etc., routed through it. Figure 7.23 - Huddersfield Street, within Schofields Finishers and Dyers yard There is a small amount of adjacent land that could be used for a Water Engine with piped inlet & outlet, but access requirements for the buildings will need to be maintained. Figure 7.24 - Gala Mill Inspection Adjacent industrial buildings could be used to connect to grid. This site is deemed practicable. Hydro power potential: 1.5m3/s @ 2.0m head = 30kw inlet = 20kw Output Figure 7.25 – Gala Mill Inspection 37 Energise Galashiels – Hydropower Feasibility Study 7.2.13 Site 10a – Gala Mill Culvert Figure 7.26 –Gala Mill Culvert Location This site is not visible above ground but can be implied from the earlier C&H reports as being a potential site. The lade has been culverted through a 1.5m diameter pipe through the waste ground and industrial yard before reaching the drop in Site 10. The pipe runs beneath the stone building that is now used as a residential property at the entry to Schofield’s Yard. A drop of about 1.0m exists along the length of this pipe. There is adjacent land to accommodate a Water Engine and pipework. This site is deemed possible with further detailed survey. Hydro Power Potential: 1.5m3/s @ 1.0m head = 15kw inlet = 10kw output. Figure 7.27 - Gala Mill Culvert Inspection 38 Energise Galashiels – Hydropower Feasibility Study 7.3 The Gala Water 39 Energise Galashiels – Hydropower Feasibility Study 7.3.1 Site 1 – Laidlaw & Fairgrieve’s Cauld Figure 7.28 – Laidlaw & Fairgrieve’s Cauld Location This site is located on the Gala Water, adjacent to the houses at Plumetree Place, upstream of the railway bridge. A drop of about 1m exists at this site, but there is no space to locate a Water Engine. This site is deemed impracticable Figure 7.29 – Laidlaw & Fairgrieve’s Cauld Inspection 7.3.2 Site 2 – Skinworks Cauld Figure 7.30 – Skinworks Cauld Location This site is located in the Gala Water to the North West of B&Q. This site includes a substantial weir with a drop of 2.8m. This weir has a very sensitive fish pass that allows migratory fish to pass beyond the weir. Any work around this weir will need to take cognisance of the need for this fish pass to remain effective. The arrangement of this weir has changed over the years and there is now a large section of the original infrastructure which is redundant, and heavily overgrown, where the original offtake channel once was. Beneath this offtake channel there is a substantial area of level ground at river level where a Water Engine or an Archimedes Screw could potentially be located. Adjacent industrial buildings could be used to connect to grid. This site is deemed practicable. Hydro power potential: 3m3/s @ 2.8m head = 85kw inlet = 60kw Output Figure 7.31 – Skinworks Cauld Inspection 7.3.3 Site 2 – Electric Cauld This existing weir has been partly dismantled and a gap now exists in the middle of the structure. The river has a gradual fall along this art of its length with a substantial area of level ground alongside the river. Figure 7.32 – Electric Cauld Location It is presently unclear whether permission could be granted for the original weir to be rebuilt and thus create its original intended drop of about 0.5m. It is considered possible that this would be permitted so long as fish passage can be catered for and flood prevention measures included in the design of the hydro system. Assuming that a Water Engine could be installed along this length of the river, it could be a piped “run-of-river” type of installation that made no use of the weir, or a system that uses only the weir drop, or a hybrid of the two options. Figure 7.33 – Electric Cauld Inspection The site has some potential problems with access for construction traffic if the water engine is located on the level ground between the river and the railway. Any impacts on the railway line during construction of the system would present major difficulties for the project, so would need to be avoided. The Borders College campus on one side of the river and the school on the other are equally likely consumers of power generated. The recent commissioning of the heat pump heating system using the sewer flow as a heat source could be a very attractive consumer of the energy thus providing an almost completely carbon- free heating solution for the College. Hydro power potential: 3m3/s @ 1.5m head = 45kw inlet = 30kw Output. 7.4 The Buckholm Lade 7.4.1 Site 1 – Buckholm Lade The Buckholm Lade runs to the north of Galashiels from an inlet point just south of the Torwoodlee golf course that which has no water entering the lade at present. There is a partially dismantled weir located at the inlet point. With the installation of the new Borders Railway line, two culvert pipes have been installed underneath the Figure 7.34 – Buckholm Lade Location railway bridge and will present no issues with respect to constrictions of flow. The lade then follows the A7 behind the Thomson’s Car Breakers yard before dropping 8m to the outlet into the Gala Water. As stated there is currently no water flowing through the lade and conversations with SEPA and SNH highlighted that reinstatement of the weir would be highly unlikely to be granted permission. An alternative is to create a piped inlet further up the Gala Water and direct this into the Figure 7.35 – Buckholm Lade Inspection lade thus creating the flow required. Utilising the available 8m head and a reinstated flow rate of 2m/s it would be possible to install the following hydropower scheme: Hydro power potential: Turbine unit using 2m3/s @ 8m head = 160kw inlet = 104kw Output. 8. Structural Engineering Survey of the Mill Lade 8.1 Introduction and Purpose The following text is duplicated verbatim from the report prepared by Christie Gillespie Engineers Ltd.: Christie Gillespie Consulting Engineers Ltd was instructed by Water Engine Technologies to undertake a structural inspection of the Mill Lade fed by the Gala Water in Galashiels and provide approximate costs for remedial works in the context of using the Lade for the installation of one or more hydro-electric power generating machines. The inspection was carried out on 18 September 2015 in the company of staff from Water Engine Technologies Ltd and comprised a visual inspection of the visible and accessible elements of the Lade. Inspections of the internals of some of the covered parts of the Lade were carried out by a member of the Water Engine Technologies staff. This report includes comments based on a review only of the photographs and video recordings made of these underground elements. It should be noted that not all areas of the Lade were accessed and the survey was concluded at around chainage 2500 although a cursory look over the open sections in the final 500m of the route was made. The purpose of the survey and report is to identify any areas of the Lade where the condition requires remedial works to the structural elements such as walls, culverts and retaining structures which would be necessary in relation to the installation and operation of hydro electric generating equipment and provide approximate cost estimates of those remedial works. 8.2 Town Mill Lade Background The Lade runs through the town of Galashiels over a length of approximately 3km and has an inlet and outlet to the local river, the Gala Water. The Lade was constructed to provide water for the woollen mills in the town. Its route includes both open channel and covered culverted sections. There is a proposal to utilise the Lade for installing hydro electric generating machines and this report is part of a study into the feasibility of those proposals. A detailed condition survey of the Lade was carried out by Crouch and Hogg Consulting engineers in 1985/86 as part of a flood study for the town following a significant flooding event in 1984. This condition report was made available for review and use in compiling this report. The findings of that report have been used as a reference for this report and the details have been included in this report and updated where there has been a change in the condition. Those details are included in tabulated form in Appendix 1. 8.3 Summary of Findings and Remedial Works Required 8.3.1 Summary The inspection revealed the following principal elements where remedial works will be necessary: Silt and vegetation clearing This is universal throughout most of the sections of the Lade. Large opens sections of the Lade are overgrown and clearance of this will be required to minimise the impact on water flow. This is also true of the silt deposits on the bed of the Lade. The costs for this work have not been included in the overall cost estimate as they are difficult to ascertain. Significant repairs to structures There are a few structures along the route such as retaining walls which have failed, or are close to failure or have been significantly eroded. These will need to be reinstated or require significant repairs. The evidence for some of the repairs to the underground structures is taken from the Crouch and Hogg reports. Minor repairs to structures There are a number of areas where structures require minor repairs such as repointing of masonry or local reinstatement of eroded areas. Renewal of Culverts The culverted section just upstream from and below the crossing of Hall Street Bridge consists of relatively small diameter pipes and it is understood that this currently restricts the flow of the Lade to a level which would not be sufficient for the operation of the hydroelectric machines located downstream of this section. If these culverts are to be removed and replaced with larger sections, the work required will be significant. The cost estimates for this element of work is likely to be subject to a high degree of variation and will require further investigation and specification to enable a reasonable degree of confidence to be placed on the cost of this work. In the following sections, the chainage references are based on distances from the start of the Lade and the descriptions for left and right are based on facing downstream. 8.4 Description of Defects and Recommended Actions 1. Chainage 236 to 268. There are two sections of bank wall constructed from rubble retained with timber boarding in this stretch. These have deteriorated significantly and require to be repaired by removing all the loose rubble and timber facing and replacement with masonry, concrete or gabions. The areas appear to be close to a private boundary and this will need to be taken into account in the design of the remedial works. The remedial work will be required over a length of approximately 15m to 20m. 2. Chainage 268 to 314. Just upstream of Duke Street Bridge at the access to the bus depot, a short length of brick wall retaining a path area next to the houses is leaning out. This was recorded in the Crouch and Hogg report but without any details of extent. The wall does not appear to be unstable at present but it is recommended that some remedial work is carried out to minimise the risk of further deterioration. Allowance should be included for some localised strengthening/propping works at this location. 3. Chainage 329 to 395. There is a short length of brick wall on the right hand side of relatively low height which leans outwards slightly. However this was also noticed in the C&H report but is not considered significant. 4. Chainage 550 to 560. Just downstream of the spillway weir, there are two channels with the right hand one blocked with rubble. The C&H report identifies that the stone roof is in reasonable condition but the masonry walls are suffering erosion and loss of mortar. This still appears to be the case and some patching and mortar repairs will be required. 5. Chainage 617 to 649. This is an open section with a grass banking on the left hand side and brick retaining wall in the right hand side. The wall is in good condition although there are few areas where some repointing of the joints is likely to be required. 6. Chainage 649 to 692. This is a covered section with a concrete roof slab. At the start of the section, there is steel beam supporting the deck which is suffering some deflection and corrosion. It is recommended that this is repaired and provided with additional protection. The C&H report identifies other steel beams under this section which are significantly deflected and this may require further investigation to determine the current condition. 7. Chainage 692-714. Short open section near McDonalds. The walls are brick and masonry and generally in good condition. A few small areas may require some repointing. 8. Chainage 753 to 798. There is a section of brick retaining wall on the right hand side alongside Graham’s Bathroom and Tile showroom just upstream of the culvert under the access road to the premises which is leaning over the Lade and is close to failure. This will need to be replaced over a length of about 20m. A gabion wall may be suitable for this stretch presumably subject to agreement with the adjacent business owner. Upstream of this wall the right hand bank appears not to be retained and it is recommended that this is sloped back or partially retained also. The left hand side wall is brick and masonry. It is in reasonable condition on the Lade side but may require some repointing in a few places. On the road side, the wall has suffered damage in some places with areas of the masonry missing and although not impacting on the wall stability, it is recommended that these are repaired. 9. Chainage 798 to 882. This covered section runs under the access road and builder’s merchant yard. C&H report notes that this covered section has a concrete roof in poor condition with support beams and there are collapses of the roof and walls leading to restricted access for inspection. It is not clear whether there has been any remedial work carried out in the time since although photos of the culvert entrance area are limited. This was an area that was blocked in the past and contributed to the flooding event in 1984. It is recommended that the section is checked in detail to determine whether any remedial work is required. 10. Chainage 882 to 956. Part of this section has been culverted using 3 pipes of approximately 450mm diameter. It is understood that this will impact on the flow required for the water engine installations and will require to be either opened up or replaced with a larger culvert. The section is understood to be on private land. There is a short open section with a concrete base and brickwork walls downstream of these pipes. The Lade then runs into another 3 slightly larger diameter pipes becoming the crossing below the Hall Street Bridge. This piped culvert arrangement is also understood to be likely to impact on the Lade flow capacity and will also require replacement. This is a significant piece of civil engineering works. 11. Chainage 974 to 1033. This open section has a brick retaining wall on the right hand side and a combination of natural slope and low brick retaining walls on the left. The low brick walls are eroded and also damaged by the growth of trees. It is recommended that these walls trees are removed and the bank either reprofiled and/or the walls reinstated. The wall on the right hand side extends above the higher ground level on this side providing a barrier wall to the existing car park. The wall above ground leans out slightly but does not appear to be unstable. The lean was evident and reported in the C&H report and does not appear to be significantly worse. It would however be prudent to survey the wall and monitor it over a period to ensure it is not continuing to move. 12. Chainage 1033 to 1188. The Lint Burn joins the Lade at around chainage 1033 and contributes significantly to the flow of the Lade. Beyond this section the Lade is covered and passes through the old SSEB premises yard. The C&H report includes reference to this section as being in generally good condition. This section was not reviewed at this time and it is recommended that a further inspection is carried out over this length. 13. Chainage 1434 to 1593. This is an open section from Bank Street Bridge running alongside Bank Street Gardens. There is significant undergrowth with trees growing out of the bank restricting the inspection. There is a brick wall bordering the gardens and the C&H report notes that there is evidence of the masonry retaining walls being in need of repair. It is recommended that a further inspection of this length is made and it would be prudent to allow for some repairs along this length. 14. Chainage 1593 to 1773. This is a culverted section with open areas around the Cornmill Square fountain. This is in good condition and structurally sound. The Bakehouse Burn discharges into the Lade in the fountain area. The C&H report also records a bypass channel on the left hand side at the weir which allows diversion of the Lade back to the Gala water at this point. There is a short open section at the end of this section adjacent to the Tesco car park. There is a weir and spillway with an approximately 2m drop. This area is generally in good condition. 15. Chainage 1773 to 1858. This section is covered and the C&H report notes this as being generally in good condition. The Lade appears again at the start of the retail park. 16. Chainage 1858 to 2235. This is mostly covered with a few open sections alongside the retail park which appear to be in generally good condition. 17. Chainage 2235 to 2261. The first 6m of this is an open section with a bypass channel entering from the left hand side. The walls are of brick and masonry and in good condition. 18. Chainage 2261 to 2276. An open section with a weir and short vertical drop. There are a number of services in this section of Lade associated with the industrial premises around this area. 19. Chainage 2276 to 3034. The remaining sections of the Lade were not inspected other than a cursory view in a few places. It is a combination of open and covered sections. The C&H report records some of the open areas as having steep overgrown natural bankings. There is mention of a couple of areas of structure which require some attention. However it is understood that this section will be downstream of any proposed locations for the water engines. 8.5 Cost Estimates The cost estimates established are only very approximate due to the nature of the work and the relatively limited amount of information gathered at this stage. It will be necessary to carry out more detailed surveys to improve on the level of confidence in the extent of the work required. This will enable the preparation of a scope of work and detailed specification to enable prices to be obtained from contractors through a tendering process. Until this exercise is carried out it is recommended that a suitable risk allowance and contingency is included as part of the overall cost estimate for the works. A rough order of costs for structural related works are set out in the table below: Table 8.1 – Estimated Structural Engineering Costs Ref. Description Cost 1 Reinstatement of retaining walls and general improvement £300,000 works to bankings. (Does not include silt dredging or clearance of vegetation) 2 General minor repairs to walls and masonry structures £50,000 3 Renewal of culverts £170,000 Total £520,000 Notes to Table above: The cost of silt removal and vegetation clearance is somewhat arbitrary, although the overall cost of the repairs and the silt/vegetation clearance is given as an estimate in the Crouch and Hogg report as £250,000 (including repairs to the underground sections of the Lade) and it is understood that some of the repair and reinstatement work recommended at that time has been completed. At this stage, the extent of those works has not been identified. VAT has not been included in these figures. Contractor’s preliminaries will need to be added to the cost estimates which may vary between 10 and 20%. The cost of dealing with statutory authorities for any approvals, e.g. SEPA, Scottish Borders Council or dealing with affected landowners has not been considered and will need to be factored into the overall cost of the project. Risk Allowances at this stage are somewhat arbitrary and the cost estimate above is as likely as not to be exceeded. The range of costs could be up to 50% above and below this figure 8.6 Buckholm Lade Cost Estimate Table 8.2 – Estimated Structural Engineering Costs Ref. Description Cost 1 Weir Reinstatement £91,000 2 Inlet works £71,000 3 Lade walls £365,000 Total £527,000 8.7 Summary and Conclusions Most of the structures along the Lade are in reasonable condition with a few areas requiring repair either as local reinstatement of walls or remedial works to restore areas of eroded bankings and localized masonry repairs with repointing. There are however some risks associated with covered sections which have not been inspected in detail as part of this exercise and that have been highlighted as being in need of repair in the previous C&H report. In some cases, work may have been carried out in the past and some of the areas of the Lade have been covered over in the interim by more recent developments. Only an up to date inspection of these areas can confirm if further work is still required. 9. Economic Evaluation 9.1 Electricity connection Grid connection is an area still for discussion. It should be well noted, however, that the problems often associated with the connection of renewable energy projects to the grid infrastructure are almost entirely associated with projects with outputs in the megawatt range, rather the much smaller scale of the projects herein considered. Any typical commercial or industrial building would be expected to have sufficient electrical power infrastructure to provide an easy point of connection to the grid at this scale. There are a number of potential stakeholders who would be interested in the electricity generated by the hydropower system. Further discussions on this arrangement will be needed. If there is no demand from local users, the electricity generated can be sold into the supply network. Potential grid connection points exist close by which are likely to be suitable for connection of the proposed options. Initial conversations with the local District Network Operator (DNO), Scottish Power Energy Networks (SPEN) indicate that there is capacity within the local grid, however cost of such connections would need to be established. A three-phase grid connection will be required, complying with the G59/82 standard, which means that stringent parameters must be met to satisfy the SNO. Connection costs consist of fitting a suitable cable between hydropower generation units and a three-phase transformer, with possible upgrading of the existing transformer and local power lines. Suitable safety protection equipment, mains interface control unit, total generation meter and export meter will also need to be fitted at the hydropower unit-side of the connection. 9.2 Operational Costs Ongoing costs which must be taken into account include insurance, rates, meter reading charges, machine overhaul and servicing costs. The use of Water Engines and Archimedean screw technologies dispenses with the need for fine screens, whose cleaning can considerably increase the maintenance. Using both of these low-head technologies not only reduces the operational cost, but minimises the extent to which debris build- up between such cleaning operations reduces the flow and affects the total annual output of electricity. 9.3 Income Income from all hydropower projects is calculated on the basis of the Feed-in-Tariff. This tariff payment is available for the first 20 years of the operation of all new small and micro-hydropower installations. The table below shows the current Feed-in-Tariff rate. The UK government has just completed its consultation on these tariffs (Jan 2016) and the following table shows the current rates: Table 9.1 – Current Feed-in-Tariff subsidy Rated Power Feed in-Tariff Generation Export Total ≤ 100kW 8.54 4.85 13.39 100 – 499kW 6.14 4.85 10.99 500 – 1.9MW 6.14 4.85 10.99 >2MW 2.18 4.85 7.03 The price obtained from FITs is made up of a generation element and an export element. Any scheme where electricity is consumed on-site (‘displaced import’) is likely to enjoy benefits in excess of those outlined in table 7.1, due to the higher retail costs thus avoided. When considering displaced import, an offset retail rate of approximately 10p/kWh may be used in place of the export element. 9.4 Financial Returns – Mill Lade The following section will review each project on an individual basis to give some indicative scheme costs, the installed capacity, the energy generated and the payback period for each project. Table 9.2 – Galashiels Mill Lade Hydropower Potential Site Installed Energy CO2e emissions Total financial Total Payback capacity generated reductions return scheme period (per annum) (tonnes per year) (per annum) cost (years) Galabank Weir 7 kW 37,838 kWh 17 £5,067 £59,200 12 Wilderhaugh Mill 7 kW 37,838 kWh 17 £5,067 £61,600 12 Rosebank Mill 6 kW 30,271 kWh 14 £4,053 £57,000 14 Botany Mill 9 kW 49,190 kWh 22 £6,587 £68,000 10 Cornmill 12 kW 117,472 kWh 53 £15,730 £136,869 9 Midmill 20 kW 156,629 kWh 70 £20,973 £81,700 4 Woollen Factory 5 kW 39,157 kWh 18 £5,243 £67,500 13 Huddersfield Mill 12 kW 93,978 kWh 42 £12,584 £79,500 6 Gala Mill 20 kW 156,629 kWh 70 £20,973 £81,700 4 Gala Mill Culvert 10 kW 78,315 kWh 35 £10,486 £76,000 7 Total 108 kW 797,317 kWh 359 £106,761 £769,069 7 9.5 Financial Returns – Gala Water This section of the report focusses on the hydropower potential of the Gala Water at the Skinworks Cauld and the Electric Cauld. Three potential hydropower systems have been specified at the Skinworks Cauld. The first is a Water Engine unit constructed beside the weir. This works will involve significantly more civils work. The second Water Engine project is located above ground beside the weir. This significantly reduces the civils costs associated with the devices installation. The final option is the installation of an Archimedes Screw. This device would be placed on the weir. Mann Power Consulting provided an estimate for a 65 kW Archimedes Screw. Only costs associated with the purchase of the Screw were provided. The energy generation figures for the Water Engines were based on flow rates of 3m3/s as per the flow duration curve in section 4. The Archimedes Screw has been calculated on a flow rate of 3.6 m3/s. Table 9.3 – Gala Water Hydropower Potential Site Installed Energy CO2e emissions Total financial Total Payback capacity generated reduction’s return (per scheme period (per annum) (tonnes per year) annum) cost (years) Skinworks Cauld – 60 kW 603,647 kWh 272 £80,828 £302,200 3.8 Water Engine (underground) Skinworks Cauld – 30 kW 301,823 kWh 136 £42,293 £222,900 5.3 Water Engine (overground) Skinworks Cauld – 65 kW 748,993 kWh 337 £99,991 £490,000 4.9 Archimedes Screw Electric Cauld 30 kW 323,382 kWh 146 £43,301 £199,000 4.6 9.6 Financial Returns – Buckholm Lade This section of the report focusses on the re-instatement of the Buckholm Lade as a potential Hydropower resource. This project is being considered as the project that will be put forward for phase 2 of the Challenge Fund application. Therefore this project would not be eligible for FITs so the financial returns for this project are based purely on the export tariff of 3.85p/kWh. If the Buckholm Lade project was eligible for FITs then this project would generate in the range of £115,000 per annum giving a payback period of approximately 6 years. Table 9.4 – Buckholm Lade Hydropower Potential Site Installed Energy CO2e emissions Total financial Total Payback capacity generated reduction’s return (per scheme period (per annum) (tonnes per year) annum) cost (years) Buckholm Lade 104 kW 862,353 kWh 388 £94,773 £420,000 4.5 Appendix 1 – Detailed Descriptions of the Lade by Chainage This table includes the descriptions of the conditions recorded in the Crouch and Hogg Reports with modifications based on the observations made during the site inspection. The Crouch and Hogg descriptions from chainage 1932 to the end have not been modified. There is a long covered section from 1033 to 1188 through the yard that was part of the SSEB building which has not been inspected by either Crouch and Hogg or for this report due to access not being possible. The reference points an chainages are taken from the Crouch and Hogg report drawings. Section Chainage Description Inlet to A 0 -38 Masonry arch culvert – Good condition. Deep Silt. A - B 38-117 Mill Lade Pumping Station intake and open channel downstream. Overgrown bankings. Extensive weeds in bed. B - C 117-115 Open channel. Extensive undergrowth on bankings and extensive weed growth and silt on bed. C – D 155-180 A72 Road bridge, masonry arch – generally good. Silt. 300mm sewer. Invert approximately 200mm above water level. Ach stones dislodged locally. 800mm to underside of arch. D-E-F 180-236 Open channel. Right hand brick wall in good condition. Left hand bank has a relatively recent gabion retention construction and a concrete wall. Between the gabion retention and the road, the ground has been locally reduced in level below that of the road to form what appears to be a retention basin within a landscaped area. Weir and mill intake at chainage 198 (E). Overhanging trees, service pipes cross at water level and Mill ducts discharging into Lade. F 236 Access bridge. Masonry walls, brick arch. Relatively new brickwork. Stoney bed. F - G 236-268 Open channel. Left hand retaining wall of stone and timber construction – moderate to poor. Timber boarding has collapsed in places and some of it is missing. The stones are falling into the lade itself. The right hand wall is masonry and is in good condition. There is extensive weed growth and silt in the bed. G – H 268-314 Open channel. Left hand bank collapsed. Masonry wall and banking in poor condition. Right hand wall is masonry construction in good to moderate condition. Extensive overgrowth on bankings and extensive silting on the bed. Left and right hand banks become natural slopes. Upstream of Duke Street, the left hand masonry and brick construction wall is leaning outwards. The overall height of the wall is 1.4 to 1.5 metres. H – I 314-329 Bridge at Duke Street with masonry abutments. The deck is reinforced concrete support on steel beams and there are a number of services to the underside of the deck. There is some silt deposition along with debris and rubbish accumulation. I - J 329-395 Open channel. The left hand wall is 1.2m high brick wall which is in good condition. This gives way to natural banking which is badly overgrown. The right hand wall is concrete in fair condition which becomes a brick wall which is in good condition but overgrown. From chainage 350m onwards, pipes some of which may be live discharge into the Lade. The right hand retaining wall is leaning outwards. Dense weed growth and silt in the bed. Disused Mill intake screens at right hand side at Chainage 390. The following sections between chainages 395 and 540m were not inspected and the notes included here are from the Crouch and Hogg report dated 1985/6. J – K 395-438 Open channel, retaining wall on right bank in moderate condition with a slight outward lean. Minor erosion at water level. Left hand bank densely overgrown then poor quality stone and timber retaining wall, narrower towards chainage 438. Pipes discharging into Lade over this section. Two steel ducts cross Lade immediately above water level at chainage 438. Rubble and debris on bed. K – L 438 – 453 Open channel. Brick/masonry retaining wall in poor condition on right hand side. Natural bank on left extensively overgrown. L –M 453 – 496 Covered section. Right hand abutment wall, masonry construction in reasonable condition. Left hand abutment wall concrete/blockwork, good condition. Roof construction of reinforced concrete slab on precast concrete and timber support beams. Internal inspection incomplete between chainage 453 and 480 due to restricted headroom. M – N 496 – 515 Open section. Right hand wall masonry construction requiring repair. Left hand stone wall requires repair and overgrown above. Silt and weed growth on bed. Trees on banking. N – N1 515 – 540 Covered section. Concrete abutment walls and reinforced concrete slab over in good condition. Central brick spine wall in good condition. Silt in left hand channel. The inspection resumed over the following sections N1 – N2 540 - 550 Open channel and spillway crest with masonry side walls. The weir drops 900mm and likely to be further weir drop downstream but in a covered section. N2 – N3 550 – 560 Covered section. At N3 abutments of brick and masonry construction with concrete roof on steel beam giving only 400mm clearance from bed level. Debris appears to be accumulating upstream of this section. Left hand channel clear but right hand channel is blocked with rubble from side wall and debris. Stone roof in reasonable condition but masonry walls suffering erosion and loss of mortar. N3 – N4 560 – 563 Open section, masonry walls and rubble bed. N4 – N5 563 – 580 Covered section. Masonry abutments, brick arch in good condition. Considerable debris in bed. Service pipes fixed to walls at water level. At N5, factory extension has been built over the lade with brick and concrete abutments and steel beams. Left hand wall and roof are in good condition but loss of pointing to right hand wall. Roof changes from brick to stone and is then covered by a Portacabin office. Cables and other services along left hand wall. Steel beams restrict headroom. N5 - P 580 - 617 Open section. Left hand is natural banking and right hand is a masonry/brick wall in reasonable condition. Stoney bed with minor silting. P – Q 617 – 649 Open section. Left hand landscaped banking. Right hand brick retaining wall in good condition although some repointing required in places. Q – R 649 – 692 Cover section. Walls on both sides are masonry and brick construction with concrete roof slab. It is apparent that there is a weir in this section with a fall together with lagoons and a bypass arrangement for presumably for the former mill wheel. The bed is generally rubble and silt and there are cast iron columns in the widened lagoon section. The steel beams supporting the entrance to the covered section are significantly deflected and corroded. R –S 692 – 714 Open section. Both walls of masonry and brick construction with some erosion. There are two steel beams at section R just above the water level and a service pipe at S just above water level. Rubble and debris on bed. S – T 714 – 724 Access bridge and covered section. Steel and concrete slab construction. Underground inspection impossible due to restricted headroom. T – U 724 – 753 Open section. There are masonry walls on both sides of the Lade and on the right hand side, the wall has a significant lean and will need to be replaced over a length of about 20m. Left hand wall becomes the pavement retaining wall and is in reasonable condition. Some small areas of repointing may be required. Debris rubbish and silt on the bed. U – V 753 – 798 Open section. Brick underbuildng and masonry retaining wall to pavement which is in need of some repair to areas with holes. Right hand bank is a natural slope to ground level and is overgrown. Debris and silt in bed. V –W – W1 798 – 882 Reinforced concrete culvert section with restricted headroom. Concrete roof in poor condition with support beams at 3m centres. Collapse of roof and walls restrict access. Silt and rubble on bed. Section 848 to 882 is blocked for 18m due to silt and rubble from roof and walls – very poor condition. Location of previous debris accumulation leading to flooding in Island street in 1984. W1 - X 882 - 942 This section has been partially covered and the Lade is culverted with 3 No. pipes of approximately 450mm diameter. There is a small open section with debris screens which will require to be removed. A new larger culvert is required here. X-Y 942-956 Hall Street Bridge. Trash screen at X, access not possible. masonry construction to abutments and arch. At YY, concrete bridge in steel beams. gas pipe below roof level near XX. rubbish on bed. Y-Z 956-963 Open section. Left hand masonry wall eroded in places. natural right hand banking. Rubbish on bed. Z-Ab 963-974 Covered section. reinforced concrete slab on brick abutments.1.5m drop weir at chainage 968 and from weir to end, bed is clear. 3 service pipes run across channels below roof level. Latterly Lade is choked with rubbish. Ab-Ac-Ad 974-1033 Open section. Left hand wall of masonry construction leaning over, giving way to natural overgrown slope. Right hand wall of masonry and brick construction in good condition, but leaning out at car park level in places. Rubbish and dense weed growth on bed. Ad-Ae 1033-1188 At section Ad the Lint Burn joins the Mill Lade at CH.1033 in right bank. Covered section through S.S.E.B yard. Assumed reinforced concrete roof slab. Access not possible for inspection. Ae-Af 1188-1225 Open Section. Left hand brick wall in good condition, giving way to natural banking. Right hand banking extensively overgrown. Extensive weed growth and silt on bed, particularly on left hand side. Af 1225 Pedestrian Footbridge. Covered section constructed with precast concrete box covert. Good condition but bed scouring at upstream and downstream ends. Af-Ag 1225-1276 Open Section. Left and right bankings generally natural slope but some brick or stone retaining walls. Extensively over grown and debris and rubbish on bed. Ag-Ah 1276-1307 Open Section. Natural bankings, extensively overgrown. Rubbish and debris on bed. Ah 1307 Covered Section. Timber and corrugated iron shed giving only 150mm clearance above water level. Ai-Aj 1321-1342 Brick building over Lade. Access not possible due to security fence. Aj – Am 1342 -1354 Open section with brick walls in fair condition. Two service pipes crossing the Lade. Heavy vegetation to both sides. Concrete footbridge at Am. Silting in bed. Am-Am1 1354 –1383 Covered section. Inspection not possible. Am1 – 1383 - 1420 Open Section. Neutral bankings but inspection very difficult due to Am2 extensive tree, bush growth etc. Width reduced due to silting and debris. Am2 – An 1420 - 1434 Bank Street Brae Bridge – Covered Section. Brick abutments and arch in good condition. Round gulleys discharge through arch. Debris and silt on bed. An – Ar 1434 - 1593 Open section with neutral bankings now overgrown with trees and shrubs. Evidence of masonry retaining walls at intervals in poor repair. Rubble and debris on bed. This section accumulates rubbish etc from Bank Street Gardens. Ar – As 1593 -1752 Culverted Section including open fountain area at Cornmill Square. Reinforced concrete wall and roof from Public Toilets to fountain, good condition. Service pipes across culvert. Debris on Bed. Fountain Area – Bakehouse Burn discharges through masonry arch culvert on right hand wall. Two major falls and sluice gates together with overflow weir on left hand wall. It would appear that this is an overflow/ bypass to allow diversion of the Lade to the Gala Water via a culvert u8nder Market Street. There is also an additional bypass channel which reconnects with the Lade further downstream but is extremely silted. Under Paton Street the Lade runs in a masonry arch culvert of good condition with the bed having no weed and little silt. As – At 1752 - 1773 Open Section. Brick retaining wall to both sides in good condition. Masonry weir crest and channel in good condition. Weir drops by 2 meters. Weed growth and silt on bed. At – Au 1773 - 1858 Covered Section. No inspection possible due to restricted headroom. Au – Av 1858 - 1878 Open Section. Both walls of brick construction in good condition. Tree and weed growth on bed and bankings. Av – Aw 1878 - 1920 Covered Section. Both walls of brick construction in good condition. The following section is now under the new retail park for the large part with some short sections that are open. It is generally in good condition. Aw – Ay 1920 -1932 Section with central vehicular access bridge. Left hand wall of good condition concrete. Right hand wall of brickwork with minor deterioration at water level. Some silting on bed. Sluice gates at screen at Ax. Ay - Az 1932 - 1972 Covered section. Full inspection not possible. Twin culvert system at entry underbuilding but only one exit archway. Az - Ba 1972 –2020 Open section. Both walls of brickwork in reasonable condition. Drains discharging to Lade, Weed growth in bed. Steel beams and ducts across Lade. Ba – Bb 2020 -2075 Covered section. Roof of reinforced concrete on steel beams and brick walls. Bb – Bb1 2075-2150 Covered Section. Lade runs in 1.5m diameter concrete to underground chamber. Bb1 - Bc 2150-2235 Covered section – no inspection. Bc – Bd 2235-2261 Open section of 6m length. Bypass channel enters on left hand side. Both walls of brick and masonry construction in good condition. Upstream arch in good condition. Signs of movement to left hand side of downstream arch. Weeds, sit and debris on bed. Pipes and ducts in Lade. Covered section of 20m not inspected. Bd - Be 2261-2276 Open section. Weir with vertical drop. Both masonry walls in good condition. Series of screens and side weirs in Lade. Silt and weed growth in bed. Ducts and pipes through both up and downstream culverts. Be – Bf 2276-2391 Covered section. Inspection not possible. Bf – Bg 2391-2424 Open section. High steep overgrown bankings on both sides. Left hand wall of masonry arch is deteriorating. Weed growth and silt on bed. Bg – Bh 2424-2448 Covered section. Entrance to BT yard. Twin 1.5m diameter concrete culverts with concrete wing walls. Bh – Bi 2448-2499 Open section. Natural steep densely overgrown bankings. Debris on bed. Left hand masonry wall upstream of bridge in reasonable condition. Bi - Bj 2499-2508 Covered section, Armco culvert. Bj – Bl 2508-2750 Open section. Left hand retaining wall of masonry construction 3 to 3.5m high for 25 metres in good condition then poor condition wall 1.5m high for a further 30m. On the right hand bank a steep natural slope for 20m is followed by a 30-35metre stretch of gabion baskets rising 2m above water level. Banking graded back to roadways. From Bj Lade is narrow but widens out over gabion section and narrows again at end of gabions. Remainder of route has steep natural banks with extensive undergrowth and trees. Weed and debris on bed. On left hand bank Lade is constricted by banking built to retain a pathway. Bl 2750 Footbridge over Lade and Gala water from Dale Street to Glenfield. Brick piers to bridge in good condition. Bl – Bm 2750-2840 Open section. Small drystone retaining walls in poor condition on both banks supporting natural bankings which are overgrown with scrub and trees. Timber footbridge to allotments at chainage 2820 in poor condition. Bm 2840 300mm diameter steel pipe in steel truss bridge. Bm – Bs 2840 -3014 Open section with natural bankings on both sides densely overgrown with trees, shrubs etc. Bed of Lade varies in width and is silty with considerable debris. There is a spillway weir over which the Lade discharges. At 2903 there is a low level service pipe with cover. Bs - Bt 3014-3034 Open Section. Natural banks covered with trees and shrubs. Gravel bed to junction with Gala Water. Appendix 2 – Town Lade Refurbishment Costings Galashiels Town Lade Refurbishment: The costings for this work are in the form of preliminary estimates only, based on visual survey without detailed structural analysis. The costs break down into 3 elements: 1. Reinstatement of failed and eroded walling 2. General wall repairs & repointing 3. New culverts and/or open channels Element 1: Allow for 4 bricklayers / masons on site for 16 working weeks Labour @ £50/hr all-inclusive 4 operatives x £50/hr x 37.5hrs x 16 = £ 120,000 Rebuilding of walls in engineering brick @ £370/1000 bricks Approximate square meterage = 1,000m2 Brick quantity @ 150 bricks/m2 = 150,000 Material cost = 150 x £370 = £ 55,500 Plant costs = £ 25,000 Total = £ 200,500 Add provisional sums to cover: Surveys, design, approvals, phasing constraints, etc. = £ 50,000 Contingencies = £ 49,500 TOTAL COST FOR ELEMENT 1 = £ 300,000 Element 2: Allow for 2 bricklayers / masons on site for 8 working weeks Labour @ £50/hr all-inclusive 2 operatives x £50/hr x 37.5hrs x 8 = £ 30,000 Rebuilding of walls in engineering brick @ £375/1000 bricks Approximate square meterage = 200m2 Brick quantity @ 150 bricks/m3 = 30,000 Material cost = 30 x £375 = £ 11,250 Plant costs = £ 5,000 Total = £ 50,000 TOTAL COST FOR ELEMENT 2 = £ 50,000 Element 3: Item A, Upstream of Hall Street: Approximate length of culvert to be replaced = 50m Excavation of 40m3 soil + 20m3 concrete = £ 2,000 Construction of new culvert Concrete base slab = £ 1,500 Brick walls = £ 15,000 Concrete roof slab = £ 1,500 Formwork = £ 3,000 Reinforcement for both slabs = £ 1,000 Total for Item A = £ 22,000 Item B: Hall Street Culvert This is a difficult piece of work in the middle of occupied areas. Approvals, service diversions, traffic management and phasing of works to maintain access will be the subject of further detailed consideration. Excavation and disposals = £ 30,000 2-stage construction of new culvert = £ 75,000 Reinstatement of services road and pavement, etc = £ 10,000 Making good around lade interface between New and existing structures = £ 10,000 Total for Item B = £ 135,000 Add provisional sums to cover: Surveys, design, approvals, phasing constraints, etc. = £ 13,000 TOTAL COST FOR ELEMENT 3 = £ 170,000 The total cost for restoring the Town Lade to fully operational condition is estimated at £520,000 + VAT. Buckholm Lade Refurbishment: 1. Alterations to inlet £ 50,000 2. Silt removal from lade £ 30,000 3. Tree / stump removal £ 20,000 4. Rebuilding of lade walls and floor £ 200,000 5. Outlet pond £ 20,000 Sub Total for Lade restoration £ 320,000 6. Water Engine 1 a. Inlet channel £ 25,000 b. Base platform £ 45,000 c. Caisson £ 12,600 d. Chamber fit-out + inlet/outlet pipes £ 14,600 e. Floats £ 10,300 f. Steelwork £ 8,100 g. Hydraulics £ 10,000 h. Electrics & Controls £ 13,300 i. Temporary works £ 10,000 j. Superstructure £ 10,000 k. Fees & insurances £ 15,000 l. Prelims and contingencies £ 15,000 Sub Total for Water Engine 1 £ 188,900 Appendix 3 – Hydro Power Systems Costings Town Lade Project 1: Galabank Mill 1. Break-ins to existing structure £ 500 2. Excavations £ 2,800 3. Caisson £ 7,900 4. Chamber fit-out £ 4,600 5. Floats £ 7,700 6. Steelwork £ 7,100 7. Hydraulics £ 6,900 8. Electrics & Controls £ 8,200 9. Superstructure £ 7,000 10. Sundries £ 1,500 11. Fees £ 5,000 Total Cost £ 59,200 Town Lade Project 2: Wilderhaugh Mill 1. Costs as per Site 1 £ 59,200 2. Extra over cost for additional 20m of inlet/outlet culvert £ 2,400 Total Cost £ 61,600 Town Lade Project 3: Rosebank Mill 1. Costs as per Site 1 £ 59,200 2. Reduced pro-rata by output (£ 2,200) Total Cost £ 57,000 Town Lade Project 4: Botany Mill 1. Costs as per Site 1 £ 59,200 2. Increased pro-rata by output £ 2,800 3. Extra over cost for 50m of inlet/outlet culvert £ 6,000 Total Cost £ 68,000 Town Lade Project 5: Waulkmill Head Site deemed impracticable £ nil Town Lade Project 6: Cornmill (The Fountain) 1. Costs as per quotation for Archimedes Screw £ 91,712 2. Full compact supplement £ 13,791 3. Remote monitoring £ 1,366 4. Fees £ 5,000 5. Civil works (Provisional Sum) £ 20,000 6. Electrical works (Provisional Sum) £ 5,000 Total Cost £ 136,869 Town Lade Project 7: Midmill (Tesco) 1. Break-ins to existing structure £ 600 2. Excavations £ 7,800 3. Caisson £ 15,400 4. Chamber fit-out £ 6,300 5. Floats £ 12,800 6. Steelwork £ 8,400 7. Hydraulics £ 8,700 8. Electrics & Controls £ 8,200 9. Superstructure £ 7,000 10. Sundries £ 1,500 11. Fees £ 5,000 Total Cost £ 81,700 Town Lade Project 8: Woollen Factory 1. Costs as per Site 1 £ 59,200 2. Reduced pro-rata by output (£ 3,700) 3. Extra over cost for 100m of inlet/outlet culvert £ 12,000 Total Cost £ 67,500 Town Lade Project 9: Huddersfield Mill 1. Costs as per Site 1 £ 59,200 2. Increased pro-rata by output £ 8,300 4. Extra over cost for 100m of inlet/outlet culvert £ 12,000 Total Cost £ 79,500 Town Lade Project 10: Gala Mill 1. Costs as per Site 7 Total Cost £ 81,700 Town Lade Project 11: Gala Mill Culvert 1. Costs as per Site 1 £ 59,200 2. Increased pro-rata by output £ 4,800 3. Extra over cost for 100m of inlet/outlet culvert £ 12,000 Total Cost £ 76,000 Gala Water Project 2: Skinworks Cauld 1. Alterations to existing structure £ 40,000 2. Sheet Piling £ 33,800 3. Caisson £ 32,100 4. Chamber fit-out £ 5,500 5. Floats £ 18,000 6. Steelwork £ 9,700 7. Hydraulics £ 13,200 8. Electrics & Controls £ 13,900 9. Temporary works £ 10,000 10. Superstructure £ 10,000 11. Fees & insurances £ 17,000 12. Prelims and contingencies £ 20,000 Total Cost £ 223,200 Gala Water Project 3: Electric Cauld 1. Alterations £ 6,800 2. Caisson £ 23,100 3. Chamber fit-out + inlet/outlet pipes £ 21,100 4. Floats £ 10,300 5. Steelwork £ 7,100 6. Hydraulics £ 10,100 7. Electrics & Controls £ 12,700 8. Temporary works £ 10,000 9. Superstructure £ 7,000 10. Fees & insurances £ 11,800 Total Cost £ 120,000 Buckholm Lade Project 4: Buckholm Lade 1. Formation of outlet pond £ 20,000 2. Pipework from lade to powerhouse (40m) £ 16,000 3. Access road to outlet pond (100m) £ 25,000 4. Powerhouse £ 40,000 5. Tree clearance (20 trees) £ 5,000 6. Turbine 2.0m3/s @8m head = 104 kW £ 160,000 7. Outfall to river £ 25,000 8. Grid connection £ 50,000 Total Cost £ 341,000