Brynteg Coastal and Country Retreat is a holiday park run by Park Leisure in North Wales. During a period a sustained heavy rainfall in late 2017 a resulting flash flood overwhelmed the drainage culvert carrying a small watercourse through the site and caused extensive damage to the park.

Hydroplan was employed as a subcontractor to the main contractor, Lynwoods Building Consultancy, to carry out a Flood Risk Assessment (FRA) and provide a sizing for a replacement culvert.

The job comprised of two separate tasks. Firstly a desktop FRA was carried out so that a new culvert could be sized appropriately and installed immediately. Hydroplan then followed up with a site visit and investigation to provide suggestions for further mitigating the flood risk in the future.

Key Features:

• Flood remediation
• Estimates of return period floods
• Culvert sizing

The post Brynteg Flood Risk Assessment & Culvert Sizing first appeared on Hydroplan - Hydropower Consultancy.

Hydroplan is providing project management assistance on the 2MW hydro scheme known as Garbhaig B on the south shore of Loch Maree in Wester Ross.

The original Garbhaig A scheme (1 MW, 1997) was de-commissioned and re-engineered to 2MW by increasing the storage and head.

Hydroplan provided the initial scheme design and planning consent, all the switch-room and HV installation design, as well as flow-gauging/hydrology services, but our main role was coordinating project management during construction, in three main areas:

Grid Management
The situation with the grid was complicated by the timing of the pre-accreditation window and the additional line capacity in this part of the NW Highlands which will only be available post-September 2016. As a result of this, there was a need to manage the construction of the new connection with the distributor to match the overall programme. Additionally, it was important to subsequently manage the Garbhaig station output to allow other newly commissioned hydro schemes in the area to offset generation in order to commission their schemes. A load bank was employed to ensure that the new scheme was able to be commissioned at full capacity.

Ofgem Management
In order for the new scheme to receive FITs, the original Garbhaig A scheme was fully decommissioned and removed. This required the removal process to be documented, and to this end, a time-lapse camera was used to record de-construction, as well as the construction of the new Garbhaig B scheme.

Project Overview Management
Hydroplan provided assistance in coordinating the project management team, designers and civil contractors, keeping the client and financial backers fully appraised and maintaining the project programme.  Hydroplan provided regular photographic progress reports throughout the construction period.

The post Garbhaig Coordination first appeared on Hydroplan - Hydropower Consultancy.

Stanley Mill harnessed the power of the River Tay for 200 years before it closed in 1989. In 2003, the construction of a run-of-river hydropower scheme with an installed capacity of 840kW was commissioned by RWE and completed in 2004. Following the collapse of the intake screen at the hydro scheme in December 2015, Hydroplan was employed to carry out a Stage 1 Assessment and Stage 2 Detailed Design for the screen replacement.

The first stage study comprised an assessment of the existing structure, provisional design of uprights, acceptable loading on the bed, different design options and related head loss and approach velocity distribution. It was important to ensure that the design options considered all possible modes of the catastrophic collapse to avoid any failures in the future. In addition, the elements that remained intact following the collapse were assessed for their purpose to determine any required redesigns.

The recommendations for improvement were discussed with the client representatives to decide on the final design specifications. Subsequently, Hydroplan outlined the detailed design during the second stage, including specifications of the intake screen, support structures, walkway and reinstallation of the cleaner beam. The design utilised existing conditions on site, reused any undamaged parts of the old screen, and minimised the installation time on site.

The work on site commenced in November in 2016 and finished in December the same year, well within the allocated timeframe.

The post Stanley Mills Hydro first appeared on Hydroplan - Hydropower Consultancy.

As part of the construction of a new 6km, 40t forestry haulage road (and access for a hydro scheme) a large span bridge was required to be replaced across the River Coulin in Scotland. The current bridge was not able to handle the required traffic load requirements and the existing middle support was in a state of near collapse.

Our design team were tasked with inspecting the existing bridge and proposing the most cost-effective and quickest way to allow the construction traffic over the river to commence the construction of the hydro scheme.

After the site inspection, it was determined that the current bridge was not capable of withstanding the required load. Due to the length of the bridge, two options were proposed. A standard road bridge made of steel beams and timber decking with a concrete pier in the middle of the river or a Mabey Compact bridge compromising of longitudinal trusses formed of prefabricated modular steel panels with pinned end connections and transverse cross girders. After comparing the price and time of construction, the Mabey bridge option was chosen. This was mainly due to the speed of erection and avoidance of any works within the river, which contained spawning gravels for fish.

Once the concrete abutments were constructed on either side of the river, the main bridge structure was launched and erected from the right bank, and within a day the two river banks were connected representing a great time-saving. The old bridge was completely dismantled.

The post Coulin Bridge Replacement first appeared on Hydroplan - Hydropower Consultancy.

The Coulin Estate near Kinlochewe in Wester Ross approached their land agent’s CKD Galbraith to design and consent a 6.2km access track to facilitate the removal of their mature forestry plantation. Following an extensive planning process involving numerous external agencies, permission was finally granted in 2014.

CKD Galbraith appointed Hydroplan to undertake a design review, tendering and construction supervision of the track including

• Repair and improvement of existing 32m bridge
• Construction of a new 30m sectional bridge
• Installation of two arch culverts and numerous piped culverts

Work started in 2015 and the track was successfully completed in 2016 under the watchful eye of SNH who described it as an example of best practice for construction in upland areas upon completion.

The post Coulin Forest Access Track (CFAT) first appeared on Hydroplan - Hydropower Consultancy.

Following the decision to upgrade the existing hydroelectric scheme on Ardtornish Estate (Scotland); preliminary ground investigation confirmed that the ground conditions were not sufficient for the planned hydro scheme and a decision was made to undertake a more detailed investigation, which included rock drilling and geochemical testing of the samples.

Two 10m deep vertical rotary cored boreholes and one 10m inclined rotary cored borehole were drilled and samples were sent to a geotechnical laboratory for testing. The test results confirmed that the ground in the immediate vicinity of the proposed dam site needed to be improved in order to allow safe construction and operation of the proposed dam. It was determined that a number of holes would be drilled which would be filled with grout consisting of a mixture of cement and bentonite. A total hole length of over 400m was drilled. Over three tons of cement and bentonite were used to inject into the grout holes and after completion, each hole was tested for permeability.

The test results were accepted as satisfactory, and three years after the dam was completed, the regular dam inspection confirmed that the structure is sound and working as designed.

The post Rannoch Dam first appeared on Hydroplan - Hydropower Consultancy.

Coulin Estate is located near Kinlochewe, Wester Ross in the Northwest Scottish Highlands. In 2010, Hydroplan identified the potential for five run-of-river schemes on the estate and planning consent was granted for all sites in December 2013. Hydroplan proceeded with the construction of three schemes, due to unviable economics and environmental protection status associated with the other two sites, respectively.

The three schemes, Torran-Cuilinn (100kW), Easan Dorcha (995kW) and Coire Crubaidh (100kW), include four intakes and three powerhouses. In addition, a private electrical network (11kV) was built to connect two of the more remote powerhouses to the grid via the Coulin Pass.

In addition to this, a new 6km access track was built which served the dual purpose of providing a suitable route for vehicles during the construction of the hydro schemes and also as a haul road to remove the existing mature forestry on the estate. Read more about this here – Coulin Forest Access Track (CFAT)

Construction of Coire Crubaidh began in September 2016 and in August 2017 for Torran-Cuilinn and Easan Dorcha. All three schemes were completed in October 2018.

The post Coulin Estate first appeared on Hydroplan - Hydropower Consultancy.

The Ederline hydro scheme (1900kW) is located to the southwest of Loch Awe in the west of Scotland. In 2009, Hydroplan began with the development of the scheme, which included a dam on Loch Gainmheach. The dam spans the mouth of the Socaich Burn and by raising the loch level it reverses the flow into the adjacent Loch nan Ceàrd Mòron, which has an intake to the penstock pipeline at the far end. A compensation flow is passed through the dam, continuing its natural flow downstream. At times of high water levels, the excess water flows unimpeded over the dam to join the natural river flow. The dam was completed in October 2013.

The scheme has a static head of about 214m which is converted to electrical energy via a twin Jet Pelton turbine. The turbine is controlled autonomously by a programmable logic controller (PLC) and operated through a human-machine interface.

Embedded within the PLC are Stop Start Initialisation (SSI) and reservoir fluctuation control smart control loops. The SSI allows the revenue of the stored water to be optimised at times of day when the best energy prices are available by breaking down the 0.7m reservoir operating range into four water level bands. At times, manual override is required in certain weather events to optimise revenue.

On Loch Gainmheach, artificial rafts are installed during the summer months to encourage the breeding success of a native protected bird species – the Black Throated Divers. The operation of the reservoir is aligned with this aim by controlling water level fluctuations to less than 0.4m per week. This restriction has been successful except at times of flood or drought events.

The post Ederline first appeared on Hydroplan - Hydropower Consultancy.

Ardtornish Estate is a remote rural landholding on the west coast of Scotland.  Hydropower has been used on the estate since the mid-1800’s – initially for mechanical purposes and then later for hydroelectric power generation with the installation of a Gilkes turbine in 1960.  A large scheme was then installed on the Rannoch River in 1996.

Hydroplan was employed by the estate in 2007 to review the potential on the estate including the replacement of the 1996 scheme, which was performing badly.

Two storage schemes were identified on the Rannoch River – Rannoch (1.5MW) and Tearnait (700kW).  Planning consent for these two schemes was obtained in May 2009 and construction of the Tearnait scheme commenced shortly after, in November 2009, with Rannoch starting about a year later.  Tearnait was completed in May 2011 and Rannoch in May 2012.

Below the Rannoch powerhouse, there are another four meters of head available and a 100kW Archimedes Screw Turbine has been installed on the old fish farm weir to utilise this head.  In addition to this, there is a leat system extending the catchment behind Rannoch Dam and providing an additional 250kW of generation.

Elsewhere on the estate a multi-intake run-of-river scheme has been consented and constructed at Uileann (800kW) and was commissioned in November 2015.  There are also two community schemes under consideration in the nearby forest block.

Hydroplan has completed the following document to showcase the works undertaken with the hydro schemes at Ardtornish.

The post Ardtornish Estate first appeared on Hydroplan - Hydropower Consultancy.

Loch Eilde Mor was originally a feeder loch for the Blackwater Reservoir, which in turn fed the Kinlochleven Aluminium Smelter in Scotland. With the smelter no longer in use, Hydroplan was employed to consider the hydroelectric potential of the loch itself – making use of the head available down to sea level.

The scheme is technically quite challenging with steep rocky terrain and also crosses the important West Highland Way (a long-range footpath), which presented difficulties in terms of access.

Hydroplan worked with local regulators to provide a concept design for a scheme that was practical to build whilst not detracting from the natural beauty of the area.

A 5MW scheme was consented in 2011.

The post Loch Eilde Mor first appeared on Hydroplan - Hydropower Consultancy.