tresoc.co.uk · Web viewThe SHCBS development proposes to re-instate the hydro turbine on Staverton Leat. Figure 1.2, P.9 in the Fisheries Impact Assessment, shows an aerial view

Rural CommunityEnergy Fund (RCEF)

Stage 1 – Feasibility Report

Submitted by:Staverton Hydro Community Benefit Society Ltd

Date of report:January 2018

Version 16.2 Page No. 1

In 2014, the owners of Staverton Mill approached Totnes Renewable Energy Society (TRESOC) to

enquire about the potential for production of hydro power from Staverton Leat. Staverton Mill

& Leat were originally constructed in the early 19th century and the Mill was converted in the

1920’s to generate hydro electricity for the neighbouring Dartington Hall Estate. The Mill was

decommissioned in 1966 and the owners were concerned about the deteriorating structure of

the leat following restriction of the allotted flow through the manually operated sluice gates.

TRESOC consulted with local partner Fishtek to confirm the potential for a hydro power scheme

at Staverton Leat. TRESOC then established the Staverton Hydro Community Benefit Society

limited (SHCBS) to facilitate the development & operation of a 100kW hydro power plant in

community ownership.

SHCBS takes the form of a community benefit society to enable the maximum benefit from the

scheme to be returned to the local community. The key players involved in the project are the

SHCBS board, TRESOC team (project support), the Amhersts (the land owners), Fishtek

(environmental consultancy), Hydrosense (Hydro developer) and the local community who will

be invited to fund the project through a community share or bond offer, and who will also

benefit from the community benefit fund.

The key factor influencing hydro power technology choice at Staverton Leat is that the River

Dart is an important home for migratory salmon & sea trout, arriving annually for the journey

upstream to spawning grounds upstream. Extensive research has demonstrated that fish can

pass entirely unharmed through the slowly rotating Archimedes screw turbine (see Fisheries

Impact Assessment Report). The technology is well tried and locally proven at the 300kW twin

turbine power plant at Totnes Weir, 2 miles downstream from Staverton & operated by Dart

Renewables Ltd. The 100kW single Archimedes screw turbine proposed for Staverton Leat will

be supplied as a pre-manufactured unit ready for lowering into position, thereby reducing

construction time and potential disruption to an adjacent local meadow.

Community support

TRESOC has been active in publicising & promoting interest in the Staverton scheme from the

initiation of the project in 2014. Updates on progress have been provided via the TRESOC


1.Executive Summary

website and Facebook page, Staverton’s Parish Magazine, Staverton.org website, the TRESOC

AGM and through the TRESOC members and supporters email lists (550 members and a further

450 registered supporters). As part of the community engagement for this study, SHCBS hosted

several local events, these include: the delivery of the Renewable Energy Experiential Learning

(REEL) Programme to St Christopher’s Prep School Staverton; 3 ‘walk & talks’ along the Leat to

the turbine site; a presentation to Staverton Parish Council; and a meeting for all interested

parties to present the preliminary findings of the feasibility study (see Section 2 – Community

Engagement). Each of these events gave us the opportunity to gauge public perception. There

was no hostility towards the project during any of the events and the comments received were

overwhelmingly supportive. All events were well attended by pillars of the local community. It is

difficult to assess how many members of the community would invest, as some of the same

people attended the Public Meeting and the Walk & Talk sessions, which may result in double

counting. However, approximately 15-20 people who attended the Walk & Talk sessions said

they would invest and approximately 25 people from the Public Meeting were interested. The

Walk & Talk sessions gave perhaps the best opportunity to talk to people face to face in a

relaxed & informal setting. Local concerns about environmental impacts, primarily on fisheries,

and the local swimming hole, were easily addressed. The works will include repair &

maintenance of the deteriorating leat structure which also meets with local approval.

Community support for the Staverton scheme has been further boosted by the success and

popularity of the 300 kW hydro power plant at Totnes Weir. TRESOC participated with Triodos

Bank and developers Hydrosense in the fundaising effort with the local community for

construction of the Totnes Weir plant. A bond offer for £1.3m was oversubscribed in 10 days

and a subsequent share offer to raise a further £300,000, open to TRESOC Members only, was

fully subscribed in 4 weeks. A number of large & small investors from the local community were

disappointed because their applications were too late and TRESOC is keeping its members &

supporters informed of progress towards a date for the Staverton offer. Interest in local

investment has been further stimulated through the community engagement programme

described in the body of this Report.

Planning and Permitting

A pre-application planning meeting has been held on site with the local authority and SHCBS is

now engaged in commissioning the reports and studies deemed necessary for submission of a

formal planning application. The Staverton site is on private land and is barely visible across the


River Dart from a permissive footpath on the Dartington Hall Estate. The nearby Totnes Weir

hydro power plant, using similar technology, has proved very popular locally and it is anticipated

that a planning application for a less obtrusive, smaller scale plant will be welcomed.

Technical and environmental studies

Fisheries Impact Assessment & outline fish pass design: The results from the site survey

indicate that the proposed deprived reach of the Dart consists primarily of good and high-quality

spawning habitat for salmon & sea trout. The scheme would produce a small reduction in

water velocities through the deprived reach due to the diversion of water through the leat.

However, the low maximum abstraction relative to Qmean means it is considered unlikely that

any detrimental impacts would occur, while the proximity of the site to the tidal limit makes it

highly unlikely that any significant spawning activity would occur in the deprived reach. Instead,

salmonids are likely to migrate through the site to areas of spawning habitat further upstream in

the catchment.

It is recommended that a best practice Larinier super-active baffle pass is installed at the weir

above the deprived reach to improve fish passage at the site. Drawings for the fish pass

included with this Report.

General arrangement drawings & outline design: Appended drawings show that the proposed

hydro turbine can be fitted within the current structure of the leat, with only the top of the

structure showing just above ground level. This will be screened from the house by a low stone

faced wall. Electrical inverters, meters and controls will be housed in a small shed, which will be

located to minimise visual impact.

Impact on Water Framework Directive targets: The Water Framework Directive (WFD; Directive

2000/60/EC) stipulates that the ecological status of surface waters should not deteriorate, with

a target for all inland and coastal waters to achieve a ‘Good Ecological Status’ by 2027. The

general ecological standard required to achieve a good status is “the biological community

which would be expected in conditions of minimal anthropogenic impact”. The Fisheries Impact

Assessment proposes that several steps can be taken to mitigate any impacts of the scheme on

habitat quality, these include: using a precautionary abstraction ratio (50:50 above the Hands

Off Flow), an Archimedes Screw Turbine and upgrading the current fish pass to a Larinier super-

active baffle pass (with Eel pass). (See the Fisheries Impact Assessment for more information).

Power output & revenue calculations: Calculations are based on a proposed maximum abstract Version 16.2 Page No. 4

of 6 m3/s – less than half the amount permitted under the run-of-river hydro guidance. An

abstraction ratio of 50:50 above the Hands Off Flow (HOF) offers a more conservative

abstraction regime than is outlined in the guidelines for run-of-river hydropower, which permits

a maximum abstraction of 1.3 x Qmean (14.95 m3/s). Total annual power output, calculated

on 50% abstraction rate above HOF and after allowance for downtime is 428,512 kWh/yr.

Case Study

Staverton Hydro Community Benefit Society (SHCBS) has made significant progress towards

realization of a proposed scheme to restore hydro power generation to a disused leat on the

River Dart at Staverton in South Devon, with completion of a Feasibility Study supported by the

Rural Community Energy Fund. The Study includes technical and environmental assessments

prepared by local technology partner Fishtek and the outcomes from an extensive community

engagement exercise facilitated by SHCBS. The hydro power scheme, to install a 100kW

Archimedes screw turbine, will generate sustainable low carbon electricity for sale to the

neighbouring Dartington Estate.

A financial model developed in the Report, with assistance from Triodos Bank, indicates that the

scheme is financially viable and that it is feasible to raise sufficient capital from the local

community.

Work is now underway to prepare and submit a formal planning application and to obtain the

necessary permits & consents from the Environment Agency and other statutory bodies. SHCBS

Director Ian Bright says: “with the results of the Feasibility Study and with our excellent

technology partner Fishtek, it is very exciting to be on the threshold of delivering this innovative

hydro power project in community ownership”.

The community engagement plan for the SHCBS project had 4 strands:

(a) Delivery of the Renewable Energy Experiential Learning (REEL) Programme to St Christopher’s Prep School, Staverton;

(b) Three ‘walk & talks’ along the Leat to the turbine site;

(c) Presentation to Staverton Parish Council; and, Version 16.2 Page No. 5

2.Community Engagement

(d) A meeting for all interested parties to present the findings of the feasibility study.

All meetings and events were publicised through Staverton’s Parish Magazine (500 copies distributed), the Staverton.org residents email list (200 members), St Christopher’s School email distribution list (approx. 200 people), TRESOC’s members and friends email list (700) and, SHCBS mailing list (84). Posters were also locally distributed (for example see Staverton Leat Walk & Talks poster).

(a) The Renewable Energy Experiential Learning Project St Christopher’s Prep School

The REEL programme was carried out at St Christopher’s Prep School Staverton during June and July 2017. It was designed to stimulate learning about renewable energy technologies, energy generation and to introduce children to local installations. It was a 4-part module that focused on Key Stage 2 students (10 years of age) and included: student-led critical thinking around our global need for energy, a school solar and energy survey, a making day to creatively explore the challenge of moving water uphill, building simple Archimedes screws as an exercise in cooperation and site visits to see a solar farm, a wind turbine and a hydro power plant. A copy of course outline has been included (See SHCBS REEL – St Christopher’s Day Plans). There were 11 children in the class. The school has a wide catchment of about 20 miles, so not all of the children are from Staverton. The school is more than happy to publicise the SHCBS share-offer to parents. This would provide access to around 200 local people (there are 100 children at the school).

The project received a lot of positive feedback from the school and children. Headmistress Victoria Kennington thought it was “a great STEM project as it joined up education in Science, Technology, Engineering and Mathematics”. She was happy with the pitched level of understanding for the presentation and was pleased that the science content had not been ‘dumbed down’. Feedback from the children was equally positive. Thanks to a TRESOC member’s donation, it was possible to make a short film (3 minutes) which captures the children’s enjoyment-

[ https://www.youtube.com/watch?time_continue=12&v=f2yitscN1Xw ]

There were several positive outcomes from the project. The school have invited TRESOC (SHCBS delivery partner) to run the project again next year and TRESOC are working with them to help them deliver it themselves. The project opened up a dialogue between TRESOC and the school about on-site renewables and CO2 reduction. TRESOC is now developing a 6kW solar system at St Christopher’s, which will form part of TRESOC’s next solar share-offer and thus be community owned. The REEL project was also nominated for a Regen award for best community energy initiative.

(b) Walk and Talks along the Leat

SHCBS hosted three ‘Walk & Talk’ sessions which enabled local residents to learn about the

project and ask questions in a relaxed environment. The sessions started at a local pub, the Sea

Trout, and continued to the leat and to the proposed site for the turbine. Each session lasted


https://www.youtube.com/watch?time_continue=12&v=f2yitscN1Xw

approximately 2 hours and all were well attended, with 45 participants in total. The sessions

were held on a Thursday, Saturday and Tuesday at varying times to enable as many interested

people as possible to take part. Attendees were prominent members of the community such as

local councillors, business men/women and the editors of Staverton’s Parish newsletter.

Feedback received from residents was all positive, which indicates good support locally. The

main point of concern was that the ecology of the river would be affected by the hydro scheme.

Roughly a third of participants said they would like to invest in the scheme, about 15-20 people.

Should the scheme go ahead then parish residents will be given priority over other investors.

Several participants had connections to the original hydro scheme built in the 1930’s and there

were lots of lovely stories told about the site. A lady on the first walk suggested that we should

build up an oral history about the project. This has been started, two interviews have been done

so far, with the owners of the leat and a local historian, and they can be found on the TRESOC

website https://tresoc.co.uk/oral-histories-of-staverton-leat/

(c) Address to Staverton Parish Council

TRESOC MD Ian Bright has given updates on the Staverton Hydro Project to Staverton Parish

Council (SPC) on two occasions prior to award of the RCEF Grant. An offer to give a presentation

on the Staverton Hydro Project Feasibility Study was declined by SPC, with a request for Ian

Bright to attend the SPC meeting of 6th September 2017 to provide a further update during the

15 minute public forum session at the start of the meeting. During the 10 minutes allotted, Ian

Bright gave an account of recent progress and described the work underway in the feasibility

study, with an explanation of the next steps and approximate timetable for realisation of the

project. The meeting was informed that the objective of SHCBS is that ownership of the

completed hydro power plant should be held by the local community, and that it was intended

that the funds raised for construction would be open to Staverton Parish residents and TRESOC

members only, for the initial 4 weeks of the offer. Two questions were raised relating to

participation in the scheme:

Q1: Some people had missed the opportunity to participate in the bond & share offers for the

hydro plant at Totnes Weir, how much notice would be given of the Staverton offer?

A: SHCBS will continue to keep local residents updated on progress via the Staverton Parish

Council and TRESOC websites, the Parish Council’s newsletter, local events and social

media to ensure maximum notice is given to the local community.


https://tresoc.co.uk/oral-histories-of-staverton-leat/

Q2: How can I register to invest?

A: Email TRESOC to go on list of interested parties for Staverton Hydro investment. (email

subsequently rec’d.)

Work on the presentation for the SPC meeting was adapted to form the presentation on the

Feasibility Study for restoring hydro power at Staverton Leat, delivered at a public meeting in

Staverton Courtroom on 7th November 2017. Presentation appended.

(d) Presentation of Feasibility Study at Meeting of Interested Parties

The public meeting was well attended, approximately 30 people turned up (19 people registered

and about 11 more arrived unannounced). In a show of hands, the majority of the attendees

were interested in investing. Presentations were given by SHCBS, Fishtek (regarding the fisheries

impact assessment) and TRESOC (regarding the delivery of REEL). Please find the minutes from

the Q&A session attached (See SHCBS Public Meeting Q&A session attached).

During the community engagement component of this work, the opportunity arose to hold a

stall at Archimedes Screw Fest, a small local hydro festival held at Totnes Weir hydro power

plant. SHCBS spoke to about 30 interested parties and took emails of about 25 for the SHCBS

mailing list. The event was attended by about 70 people.

Summary

All community events were well attended by pillars of the local community. It is difficult to

assess how many members of the community would invest, as some of the same people

attended the public meeting and the Walk & Talk sessions, which may result in double counting.

However, approximately 15-20 people who attended the Walk & Talk sessions said they would

invest and approximately 25 people from the public meeting were interested. Furthermore,

SHCBS has email access to over 1,000 local people, this includes TRESOC members and friends of

TRESOC (approx. 700), St Christopher’s School parents (approx. 200), Staverton.org website –

Staverton Parish Residents (approx. 200) and SHCBS mailing list (84). There was no hostility

towards the project during any of the events and the comments received were overwhelmingly

supportive. The concerns raised about the health of the ecosystem and the swimming hole were

easily addressed.

Key stakeholders have been identified and contacted, these include: the local church, the parish

council, Staverton Wildlife Reserve, the local resident’s association ‘Staverton.org’, the Rivers


Trust, the local anglers club and canoe club. All have been supportive so far. The Diocese of

Exeter is very pro-renewable energy and is currently examining the potential for solar pv on

many of its buildings. The Staverton.org resident’s association has taken a keen interest in the

scheme and has helped publicise events. Staverton Wildlife Reserve is eager to see the removal

of the Himalayan Balsam and other invasive species from the leat, and its restoration to health.

The anglers and Rivers Trust are supportive of the scheme as it will replace the existing fish pass

with a state of the art Larinier Fish-pass. The National Rivers Authority deemed the existing

easement structure to be far from best practice, only being passable during periods of high

discharge. Thus the scheme will seemingly benefit many local stakeholders.

The Staverton Leat Hydro Scheme will generate environmental, social and economic benefits for

the local community:

SHCBS has been created by the Totnes Renewable Energy Society (TRESOC), specifically for

this project. TRESOC is centred around ethical, sustainable investment in local renewable

energy through community ownership. Shares in the hydro project will be offered initially to

Staverton residents to ensure that the project is locally owned and that the maximum

economic benefits are captured by residents.

The project provides the historic revitalisation of hydro power for Staverton village– the first

hydro power plant at the leat, installed by the Elmhirsts of Dartington Hall, provided

Staverton and Dartington hall with its first electricity supply. The new turbine will renew this

historic link by once again providing Dartington Hall Trust estate with the electricity

generated.

The hydro plant will generate 100kW of electricity which increase energy security and insulate Dartington Hall Trust from energy price spikes and rises.

A vital part of the project is the opportunity it presents to restore flow to the leat, a section

of waterway rich with history, which would otherwise fall to decay. Since the decision was

made by the Environment Agency to reduce water flow in the leat, the build-up of debris

and weeds such as Himalayan balsam has taken its toll, clogging the once-beautiful


3.Community Benefits

waterway. As part of the hydro project, the entire leat will be cleaned and regularly

maintained, effectively saving a local landmark. The Staverton Wildlife Reserve lies in close

proximity to the Leat, which is full of invasive species such as Himalayan Balsam. The

removal of the plants and upkeep of the Leat will help protect the Reserve.

The Community Benefit Fund income will support local community projects for the next 20-

40 years. This could be up to £5k per year depending on the structure of the investment.

The investment opportunity itself provides a rare opportunity for local people to invest

locally and access directly the economic benefits. This removes the transaction costs that

small investors usually pay on their investments.

Staverton Weir is listed by the Environment Agency as one of the Rivers Darts 10 worst black

spots for inhibiting fish migration. There is currently an old fish ladder next to the weir, but it

is of poor quality. An assessment of this easement structure by the National Rivers Authority

(Maslin, 1992) considered that it was likely to be impassable in all but the highest flows.

Instead, migratory fish were deemed likely to pass upstream through a breach in the weir

several hundred metres further downstream. The current fish pass will be replaced with

Larinier super-active baffle pass (with specialist eel pass) as part of the hydro project. The

full impact of this improvement is difficult to judge, but it has high potential, as over 1000

salmon were counted moving up the fish ladder installed at the Totnes Weir hydro power

plant during the spawning run this year. The rebuilding of the fish ladder at Staverton Weir

will allow easier passage of salmon to the gravel spawning beds at the head of the Dart.

Local People

Economically, Staverton Parish residents and TRESOC members will receive first option for

investment and our total raise is approx £800K. With a minimum share investment of £100, this

would allow a possible 8,000 people to invest, although this is extremely unlikely. (The average

local investment in Totnes Weir was £10k even though the minimum investment was £1K). 805

people live in Staverton parish and South Hams District Council has an estimated population of

84,000. All of these people could potentially benefit from social, environmental and economic

improvements that the community benefit fund makes.

Supporting Local Jobs

The project will support and secure many existing local jobs. The 4 SHCBS directors will receive a


small fee for their time spent managing the scheme. The construction element of the project will

employ local people through Hydrosense and Fishtek, although the turbines and mechanical

parts will be from further afield. The ongoing maintenance and monitoring will be carried out by

local companies Hydrosense and Argand Solutions, supporting already existing jobs. The

administration for SHCBS will be carried out by TRESOC (based in Totnes, which borders

Staverton Parish), and through Tresoc will support 5 part-time staff. TRESOC has a policy to use

local contractors and suppliers whenever possible, in 2016/17 91% of expenditure was spent

within 15 miles.

SHCBS proposes to install an Archimedes Screw at the eastern end of Staverton Leat. The

Archimedes Screw technology is considered most appropriate due to the low water head or

pressure (the intake to outlet height difference is low), and debris and fish tolerance (large

dimensions and slow speed means debris can pass easily and fish can pass with little or no

occurrence of injury. The technology also has relatively simple civil and mechanical works. A

pair of Archimedes Screw turbines are successfully operating at Totnes Weir located a mile

downstream from Staverton. Assessment of technology type was not an objective of this

feasibility study as it is widely agreed that the Archimedes Screw is the most appropriate

technology.

Technological Suitability

The same technology was used at the Totnes Hydro downstream of the Staverton site. A positive

impact on fish has been seen due to the improved fish pass and no fish injury in the turbine has

been recorded. The proposed location will benefit in the same way from low fish injury and an

improved weir with fish and eel passes (see Section 6: Fish Impact Assessment for more).

The existing leat can be used, rather than installing a penstock to build up more pressure.

However, due to the low head difference between the leat at the turbine location and the

discharge, the most suitable technology is an Archimedes Screw. This technology has produced

good results on rivers in UK, both for the river environment and in energy production.

Energy Customers and Connections


4.Technology

The energy produced will be fed into the Dartington Hall Estate mini-grid and predominantly

used by the estate. The mini-grid is connected to the national grid through a single MPAN and

any excess energy will be exported through this to the national grid. Although the site already

has a solar PV farm, it is estimated that only between 1% and 3% of the hydro energy will be

exported. This due to the high demand on site and asymmetry of the generation – in summer

when the PV is high the river flow is low and vice versa.

Costs of Grid Connection

The power will be stepped up and transported from the hydro site, across the Dartington Hall

Trust site and connect to their mini-grid at one of the HV transformers. The cost for the grid

connection is £150,000 which includes £90,000 for cabling.

Alternative technologies

As previously demonstrated, the most suited technology is the Archimedes Screw Hydro and so

other technologies were not considered.

Technology limitations

A few scenarios have been considered for different “hand-off” flow volumes (the river flow

volume below which no generation is allowed by the Environmental Agency and the turbine will

shut down). Based on 40y of recorded river flow the generation modelling has taken this into

account. So too has very high river level where the turbine in submerged and no generation is

possible.

The recorded river flow information has also shown the seasonal variation, which has also been

considered in the generation modelling.

The energy requirements of Dartington Hall Trust (DHT) have been considered. DHT have a

500kWp solar PV system on site, which only exports about 9% of its energy over a year – 91% is

used by DHT. Most of the export is in summer when the river flow is low. In winter the river is

higher and almost all the hydro generation will be used on site, when solar generation is low.


5.Financial Projections

This table lists the key considerations stated in the RCEF suggested structure, together with

responses in respect of this installation.

RCEF Feasibility Study Query RCEF Feasibility Study Response

a. What is the estimated development cost of the installation?

£53,855

b. What sources of funding have been explored?

Community shares and a bond issue (through Triodos Bank).

c. Has any research been carried out into the possibility of community share issue?

Yes. We are aware that this is an option. We also understand that it will be important to ensure that the installation is put in place in time to be eligible for the FIT, and that the developer can have certainty as soon as possible that financing will be in place. Discussions with Triodos bank and the developer indicate that a bond issue would be the clearest way to ensure these objectives are met. A community share issue could then be made to repay the bonds.

d. What is the potential income from FITS, non-domestic RHI, selling energy etc?

FITS, over term £860,436

Local energy sales, over term £2,020,782

Grid export Nil - we anticipate 100% local sales.

e. What is the potential income from the community, customers etc?

Income from community Nil, though we anticipate accessing community capital from eventual share investment, predominantly from local people.

Income from customers The figure shown above as local energy sales over term. There is a single customer, Dartington Hall Trust, which has demand consistently in excess of generation.

Running costs over lifetime £1,071,229

g. What are the likely outgoings including loan repayments, staffing, insurance etc. over the lifetime of the installation?

Loan repayments Nil, except that the RCEF loan capital will be repayable, with premium, in year 1

Members capital repayment £935,333

Members' interest payment £1,197,920


RCEF Feasibility Study Query RCEF Feasibility Study Response

Direct opex:

Rent £288,122

Insurance £163,870

Rates £160,000

O&M contract (Hydrosense) £245,810

Metering £5,410

Preventative maintenance and repairs

£0

SPV running costs - audit, board etc

£186,790

Total OPEX £1,050,002

Staffing The project will not employ staff. Ongoing maintenance will be supplied by the O&M contract. Day to day project management and administration (including invoicing, liaison with client and members) will be sub-contracted to the CBS's sister society, Tresoc.

h. What is the estimated surplus per annum which can be spent on community benefits? £5,000

The Staverton Hydroelectric Scheme requires the following planning and permitting:

a. Planning - Pre-Application Planning Advice (4090/17/PRE) for a Hydroelectricity scheme at

Town Mills, Staverton TQ9 6PD.

b. Abstraction Licence.

c. Grid Connection.

d. Flood Defence Consent.


6.Planning & Permitting

e. Legal Agreements and Consents (EA consent to take over management of the Leat.

a. Planning - Pre-Application Planning Advice (4090/17/PRE) for a Hydroelectricity

scheme at Town Mills, Staverton TQ9 6PD.

Introduction

Stephen Munday MRTPI, planning director for TRESOC, formerly Head of Development

Management at South Hams District Council, advises TRESOC on matters where its activities and

projects may involve consideration of the Planning Act and local and national planning policies

and guidance.

A formal pre-application enquiry was submitted to South Hams District Council on 27th

November 2017. The application incurred a fee of £360.00. We submitted a location plan and

photo montage type images. We were given a target date of 11 December 2017 to receive a

response, but because of staff shortages and Christmas holidays we were not able to meet the

case officer (Lucy Hall) until a site meeting on 10 January 2018.

The Scheme

The development will involve placing a concrete barrier at the end of the existing historic, but

empty, leat so that it will fill with water again. At this barrier there will be an Archimedes screw,

driven by the new head of water above the River Dart. This screw would drive an electricity

generating turbine and the current would pass through a transformer housed in a new shed

alongside the leat, then pass via a new cable under the main river and through the fields to the

existing private electrical power circuit on the Dartington Estate. There would be a new fish

ladder above the sluice gates.

Historically, the leat was constructed to provide water to power a corn mill, and then it was

converter in the late 1920s to power an electrical hydro plant which provided electricity to the

Dartington Estate for about 40 years.

Planning Issues

There is unlikely to be any problem in principle with reinstating a hydroelectricity scheme on the

site, but the Local Planning Authority is likely to see the planning issues as being the impacts on:


1. Ecological interests on the surrounding land and in the R. Dart. This is likely to involve the

need to understand principally the movement of, and any habitat changes for fish and bats.

2. Historical assets including the leat and the ancient deer park on the Dartington Estate.

3. Arboricultural/landscape value of the trees on the river bank affected by the cable route.

4. Flood water flow.

5. Visual appearance of the transformer house.

6. Noise from the transformer given the particularly tranquil setting.

7. Community support.

In terms of precedence, another hydro scheme has been recently commissioned and is on

operation one mile downstream of the site.

Progress

The site visit took place on 10 th January and was attended by Ian Bright (MD for TRESOC), Lucy

Hall (SHDC planning case officer) and Steve Munday (Panning Director. Points of discussion

included: the proposed location of the turbine, the overgrown condition of the leat, the

intended crossing point of the Dart for the cable and the existing weir and water flow

mechanism. The case officer raised no points of concern, but advised that she needed to

obtain the comments of the Environment Agency and Conservation and landscape colleagues

at the Council. She said she would try and give us a formal response in about 3 week’s time.

We advised her that if there was support in principle we would commission the studies

needed to address the likely planning issues. We sought confirmation of what information the

Council would want to accompany a planning application. From my reading of the Local

Validation List, the scheme would be a Category B development so, I envisage, potentially:

A Wildlife Report;

A Planning Statement;

Elevation drawings at an appropriate scale, including cross sections;

A structural survey of the leat, together with a repairs schedule;

A Heritage Statement;

A Flood Risk Assessment;

Noise Impact Assessment;

Landscape and Visual Impact Appraisal; and,


A tree/hedge survey.

Projected costs for submission and processing of the planning application will be estimated on

this basis following further discussion with project development partner Fishtek and

appropriate consultants.

(Please refer to SHCBS Staverton Leat Pre-planning app)

b. Abstraction Licence

Hydrosense Renewables Ltd was instructed to act on-behalf of SHCBS to obtain an abstraction

licence for Staverton Leat Hydro. A pre-application was made by Hydrosense two years ago and

a detailed response was provided by the EA. Please see the text box below for the headlines:

EA Pre-Application Response

"The appropriate assessment for the Dartmoor SAC SAP found that the optimum flows for adult migration at the Staverton site, which require the highest level of protection, were between 200-400 % of Q95 between March to October. We need you to confirm that your proposal will have a comparable level of protection to that applied in assessing the licences in the SAP. We require you to provide a hydrograph of the modelled impact of the proposal which includes no abstraction between 200-400% of Q95."

"Please provide an assessment of salmon and sea trout migration flows and how these will be impacted. The assessment should include the flows that adult salmon and sea trout use to reach the proposed site on the River Dart and how the abstraction will affect migration through the depleted reach and over the weir."

Geomorphology:

"A geomorphological assessment of the waterbody is required that describes its current characteristics and how the functional habitat could change with the proposed new flow regime. The assessment needs to consider the potential impact on habitat (particularly in the depleted reach) as well as on fish migration. Sediment transport and the risk of siltation, particularly in the depleted reach also needs to be considered."

Fish passage design:

"The location for the main Larinier fish pass is acceptable (but) the proposed size may be too small"

"Details of the fish pass will be required for approval at the application stage and prior to any licence issue."

"Details of the proposed improvements to the fish notch/ramp on the left..." Version 16.2 Page No. 17

"how the flows will be split between the two channels (separate spill routes from Larinier and notch)... The flow split must be appropriate for fish passage via both routes." –

"Details of the eel pass will be required for approval." –

Legal:

"Please provide a map clearly showing land ownership at the point of abstraction, the weir, the land adjacent to the leat, the depleted reach and at the location of the turbine" –

"We (the EA) own the leat channel... subject to agreeing terms, we would be willing to grant a licence for access to the point of abstraction... (and) a licence for access to the area where the generation apparatus is being constructed on land owned by us. We do not own the bank sides at the point of abstraction. You will need to have a right of access or a prospective right of access to one or both of the bank sides contiguous to the point of abstraction." –

Side channel: "Residual channel on left bank (NGR SX 79307 63750) appears to diverge from the leat into the field. Scheme could potentially reduce flow and impact any legal rights to this water. It is possible this channel only flows following high flows/ heavy rainfall. We advise you explore the ownership of this channel and discuss your proposal with the landowner." –

Consultation:

"We urge all applicants to consult with other local river users and interest groups, such as the Dart Angling Association (DAA), any fishing rights within the depleted reach and any canoe/ kayaking clubs, before submitting an application." – DAA and canoe club already consulted and supportive

In response to the EA’s feedback, as part of the feasibility study, output calculations have been

undertaken and a Fisheries Impact Assessment (see relevant subsections for results). A

Geomorphology Study is beyond the remit of this feasibility report and will be commissioned

prior to submission of the Abstraction Licence. Fishtek have been identified as the consultants to

provide this work given their familiarity with the project. An outline fish pass design has been

produced as part of the feasibility study, which takes into account the EA’s comments (see fish

pass designs). The legal agreements necessary for the abstraction licence are beyond the scope

of this feasibility. A list of legal agreements has been drawn up for the next stage of the project.

Community engagement was undertaken as part of this feasibility study, (see section 2 –

community engagement). Fishtek has also consulted the Dart Anglers Association and the local

canoe club as part of the FIA, both groups are supportive of the scheme.


Hydrosense are of the option that it is likely that SHCBS would be granted an abstraction licence.

The Amhersts title appears to run up to the sluices (i.e. the point of abstraction, see Staverton

Leat Land Titles Map on P.22). A full EIA has not been requested.

Output Calculations

Fishtek Consulting were commissioned to produce the generation output calculations for the

scheme, under a series of different abstraction scenarios. This generation value combined with

the FIT rate and export rate (PPA) gives the gross annual revenue for the project. The total flow

available to the turbine has been assessed using the EA’s current best practice guide for

Hydropower and data from the fisheries impact assessment.

The annual energy production is assessed using the flow duration curve for the site. This gives

the averaged percentile river flow throughout the year. Assuming Q95 hands off flow, a

proportion (50%) of the available flow above HOF is then available for the turbine. The change in

tail water at higher flows is also factored to give a net head for power generation. An allowance

is made for downtime and servicing.

Water Take Annual kW/h Gross revenue @ 7.8p FT + 8.5p export

GPG Medium sensitivity 361,000 £58,843

50% take above Q95 Hof 428,000 £69,764

60% take above Q95 Hof 475,000 £77,425

Straight take above Q85 Hof

525,000 £85,575

Fisheries Impact Assessment (FIA)

The FIA assesses the impact of the proposed hydropower scheme upon fisheries ecology in the

River Dart, Devon. Fishtek Consulting were commissioned to conduct the FIA, focusing upon

potential impacts to the availability of fish spawning habitat and upstream fish migration and to

recommended appropriate measures to mitigate any impacts identified, see attached report.

Conclusions and Recommendations


Pete Kibel, 23/01/18,

The Amhersts title seems to run up to the sluices (point of abstraction), so you can use this as evidence for the licence application. See attached.

“Results from the site survey indicate that the deprived reach, the stretch of water between the

point of extraction and return consists primarily of good and high quality spawning habitat for

anadromous salmonids. The proposed scheme would produce a small reduction in water

velocities through the deprived reach due to the diversion of water through the leat. However,

the low maximum abstraction relative to Qmean means it is considered unlikely that any

detrimental impacts would occur, while the proximity of the site to the tidal limit (1 km

upstream) makes it highly unlikely that any significant spawning activity would occur in the

deprived reach. Instead, salmonids are likely to migrate through the site to areas of spawning

habitat further upstream in the catchment.

In order to confirm the suitability of the proposed abstraction regime it is recommended that

pre and post installation monitoring is performed. This should include monitoring of fish

populations (particularly salmonid parr and smolts), quality and extent of habitat availability

with the deprived reach, redd counts within the deprived reach and dissolved oxygen

concentrations in the river.

Particularly shallow areas of river channel can delay upstream migration, of which there were

several sections identified in the deprived reach. However, at each of these locations there was

also a section of deeper water where passage was possible. It is therefore considered that there

would be no barriers to upstream migration arising from the natural morphology of the channel

if the proposed scheme were to proceed.

Although the easement structure installed on the weir at present is far from best practice, the

decreased discharge through this section may further decrease the performance of the structure

for passing migratory salmonids. It is therefore recommended that a best practice Larinier

super-active baffle pass is installed at the weir to improve fish passage at the site, in addition to

a bespoke eel pass to improve access to areas of habitat upstream” (Staverton Hydropower

Scheme Fisheries Impact Assessment, Fishtek 2017).

These recommendations have informed the design of the scheme, which includes a Larinier fish

pass and bespoke eel pass.

c. Grid Connection

The point of connection is at a HV transformer on the Darting Hall estate mini-grid. The mini-grid

is, in turn, connected to the Western Power Distribution (WPD) grid through a single MPAN.


Currently there is an export limit of that connection of 510kW, which covers the 510kWp of

solar PV on site. Even though the export limit is rarely breached, WPD require that the sum of all

generation on site be included in the allowed export. An extension of 100kW was applied for

and granted in October 2016 (WPD Ref: 2586760). This offer has now expired but recent

conversations with the officer at WPD confirmed that the offer is likely to be reissued when

applied for. The offer lasts 6 months so the timing of the application will be considered within

the appropriate timeline.

If WPD states that the export limit cannot be extended with the new application, a connection

agreement can still be reached if an approved export limiting system is added to the hydro

plant. This will ensure that there is no export by the hydro on the rare instance (it implies zero

so site demand) that the existing solar system is exporting to the full site export limit.

d. Flood Defence Consent

To apply for a Flood Defence Consent (FDC) a flood risk assessment and construction method

statement must be submitted. The Flood Defence Consent will be applied for in the second

stage of this project once this work has been carried out. A FDC is needed for pre-accreditation

of the project, but not for applying for the abstraction licence or planning. Therefore, the work is

prioritised accordingly to minimise risk. We are speaking to Hydro Logic regarding the flood risk

assessment.

e. Legal Agreements and Consents (EA consent to take over management of the Leat

The project is quite complicated in terms of legal agreements, due to the number of

stakeholders. The key legal agreements are as follows:

I. Option Agreement and Lease with Owner of Townmills

II. Wayleave consents and access to point of abstraction

III. MOU for works to be carried out with neighbours

IV. PPA/Contract with Dartington

V. Contract with WPD for Grid Connection

VI. Contact with EA for managing the leat


Staverton Leat Land Titles Map

This map details the ownership titles around Staverton Leat. As you can see the Amherts et al

own the bank that accesses the sluice gates. There are also the owners of the turbine site and

are fully supportive of the project. This legal contract should satisfy the terms of the abstraction

licence which demands legal access to the point of abstraction. For further information please

see Staverton Leat Ownership document.

The SHCBS development proposes to re-instate the hydro turbine on Staverton Leat. Figure 1.2,

P.9 in the Fisheries Impact Assessment, shows an aerial view of the site with the location of the

weir, the leat channel and proposed turbine location. The proposed location of the turbine is at

the point where Staverton Leat re-enters the River Dart, please see the general arrangement

drawing document, which shows how the turbine will sit in the leat. The Staverton Leat Land

Ownership document shows the land ownership titles around the leat. The lease agreement will


7.Site

grant rights of access to the turbine site (across a field belonging to Ann Amhurst on the North

side of the leat) and the sluice gates (across land belonging to the Amhursts et al). For the

repairs to the weir and upgrade of the fish pass to the Lainer Fishpass (see Staverton Fish Pass

Drawing) access is through land belonging to Dr V. Giblin, a wayleave agreement will need to be

in place.

Site Lease

SHCBS has negotiated a lease and 3 year option agreement with the Amhursts et al which is

ready for signature.

Technology Suitability

The head of the water in the leat is maintained through the weir. The leat previously supplied a

hydro turbine on the same site from approx. 1930 to 1970, so the site is proven historically.

Site Restrictions

The site is subject to Environment Agency Abstraction licence. The hydro scheme would abstract

a maximum of 6 m3/s – less than half the amount permitted under the run-of-river hydro

guidance. Due to this low figure, an abstraction ratio of 50:50 above the HOF would offer a more

conservative abstraction regime than is outlined in the guidelines for run-of-river hydropower,

which permits a maximum abstraction of 1.3 x Qmean (14.95 m3/s) and an abstraction ratio of

35:65 in favour of the deprived reach. (For further details please refer to the Fisheries Impact

Assessment report).

Potential Objections

Initially, the land owners approached TRESOC to develop the hydro project as the leat is in a

state of disrepair, this poses potential flooding risks to neighbouring land owners. The re-

instatement of the hydro will restore and maintain the leat. Wayleave Agreements and

Memorandums of Understanding will be negotiated as required.

Electricity Export

The electricity supply will be connected to the Dartington Hall Trust (DHT) 1MW grid main via

the route shown in the Cable Route document. The project also requires a grid connection

agreement with Western Power Distribution.


Ongoing Site Management

SHCBS will be responsible for the management of the installation on a day to day basis.

Legal Structure

Staverton Hydro Community Benefit Society limited (SHCBS) was established by Totnes

Renewable Energy Society (TRESOC) to enable the community development of a 100KW hydro

power plant at Staverton Leat. SHCBS takes the form of a community benefit society to enable the

maximum benefit from the scheme to be returned to the local community.

Key People

SHCBS, supported by TRESOC, will be responsible for overseeing the delivery and ongoing

management of Staverton Hydro. Totnes Renewables Energy Society (TRESOC) is an Industry and

Provident Society (IPS) that has been developing community energy projects for over 10 years and

has a membership of over 560 local people. TRESOC’s board of directors is a dedicated group of

expert professionals with appropriate skill sets in Renewable Energy, Engineering, Law, Finance,

Communications, Environmental Sciences, and Planning. The SHCBS board consists of three

TRESOC directors, Ian Bright, Steve Munday and Trevor Branton, and Company Secretary, Owen

Hill.

TRESOC’s Expertise

Over the last 10 years, TRESOC has developed the appropriate means of operating and

maintaining its solar pv installations and has systems in place for remote monitoring,

maintenance, engaging with its members and paying interest. TRESOC has launched three

successful share offers and raised over £490K though community share offers.

It also has experience with hydro technology and worked to deliver Totnes Weir Hydro alongside

developer Dart Renewables Ltd (DRL). It assisted with the launch of the DRL Bond Issue (with

Triodos) to finance the Totnes weir Hydro raising £1.3 million in 10 days.

Following this, TRESOC launched the DRL Share Offer exclusively to its members raising a further

£300k in 4 weeks. SHCBS will use a community Share Offer to finance the Staverton Hydro


8.Operation & Governance

scheme. This ensures the long-term ownership of the scheme by the local community. When

launched, the share offer will be available exclusively to Staverton Parish Residents and TRESOC

members for the first 4 weeks.

The financial aspect of the share offer will be administered and delivered by Triodos Bank, and the

on-going interest payments, accounts, monitoring, maintenance and general society business will

be administered by TRESOC.

Please see the Staverton Schedule document for project scheduling and milestones.

The Staverton Hydro Feasibility Study considers the viability of a project to install a 100kW hydro

power turbine on Staverton Leat, supplying electricity to the neighbouring Dartington Estate.

The project was initiated by the owners of Staverton Mill and other residents, who approached

TRESOC to assess if a hydro power plant could be installed on the Leat. Further to this, the

community engagement work carried out during this study suggests that there is wide local

support and demand for the project.

The Feasibility Study has delivered a comprehensive programme of community engagement,

including: walk & talk sessions along the leat for local residents and interested parties,

presentations to the Parish Council, a public meeting for on the outcomes of the Study and the

innovative Renewable Energy Experiential Learning (REEL) Programme delivered to St

Christopher’s Prep School, Staverton. The walk & talk sessions and the public meeting attracted

over 75 people, including parish councillors and prominent local residents. There was a rich

discussion about the impacts of the project, particularly on the environment. However, the


9.Scheduling

10. Conclusions

technical assessments carried out as part of this study suggest that it is possible to mitigate

these impacts, so concerns were despatched satisfactorily. There was general approval for local

ownership with a third of the participants registering interest in investment in the project.

The technical and environmental reports carried out by Fishtek for the study include: a Fisheries

Impact Assessment & outline fish pass design; General arrangement drawings & outline design;

Impact on Water Framework Directive Targets and power output calculations. The Reports

conclude that a 100kW Archimedes Screw Turbine with improved fish pass at the weir above the

leat is technically feasible within the constraints imposed by environmental considerations. The

Fisheries Impact Assessment proposes that several steps can be taken to mitigate impacts of the

scheme on habitat quality and the environment, these include: using a precautionary

abstraction ratio (50:50 above the Hands Off Flow), an Archimedes Screw Turbine and upgrading

the current fish pass to a Larinier super-active baffle pass (with Eel pass). (See the Fisheries

Impact Assessment report for more information). Furthermore, the FIA report indicates the

potential benefit to migratory salmon & sea trout, through the upgrading of the fish pass and

creation of an eel pass.

Financial projections for development, installation and operation of the plant are based on a

conservative rate of abstraction of 50% above the Q95 hands off flow rate. At this rate of

abstraction the project is commercially viable, financial returns are modest but judged sufficient

to procure local investment and ongoing operation & maintenance of the scheme.

A pre-application planning meeting with the local planning authority has enabled SHCBS to

determine the reports and studies required for submission of a full planning application as

detailed in the Scheduling section of this Report. The Schedule also indicates that the closest

attainable date for commissioning is February 2019 although construction would be delayed

until the summer for practical reasons.

This Feasibility Study shows that a 100Kw hydro power plant on the leat at Staverton is

attainable from a technical and commercial perspective and that there is widespread awareness

of and support for the project in the local community. The hydro turbine installation would be

owned and operated by the Staverton Hydro Community Benefit Society, with management

services contracted to TRESOC, a successful local community energy enterprise. Both TRESOC &

their chosen contractor, Fishtek are keen to bring this project to fruition.


List of Documents included with this SHCBS Feasibility Study:

Fisheries Impact Assessment Report – produced by Fishtek

Energy Capture details - produced by Mannpower

Staverton Fish Pass design - produced by Fishtek

Staverton General Arrangement Drawings - produced by Fishtek

SHCBS Public Meeting Q&A – produce by Tresoc

SHCBS REEL – St Christopher’s Day Plans - produce by Tresoc

SHCBS Staverton Leat Pre-app 2 - produce by Tresoc

Staverton Cable Route - produce by Tresoc

Staverton Leat Land Ownerships - produce by Tresoc

Staverton Leat Walk&Talks Poster - produce by Tresoc

Staverton Schedule - produce by Tresoc

Staverton Public Meeting Poster - produce by Tresoc
