Dougall Baillie Associates

Water Management Case Study One: Overview
PROJECTS: Various
From the 1st April 2006 The Water Environment (Controlled Activities) (Scotland) Regulations 2005 (CAR), made it an offence for construction sites, discharging to the water environment, to operate without a Sustainable Urban Drainage System or equivalent treatment system.

DBA offers bespoke construction phase surface water management solutions and on-going water quality monitoring to assist Clients and Contractors meet their Statutory obligations.

The service we provide identifies and assesses site specific constraints allowing development of an Erosion & Sediment Control Plan. The Plan is presented in an easy to read format that can be displayed on-site outlining contractors obligations, details of easily installed best practice techniques and emergency procedures.

In consultation with SEPA, we have developed and implemented cost effective Plans for construction projects discharging to environmentally sensitive locations such as Sites of Special Scientific Interest (SSSI) and Local Nature Reserves. In these unique situations, effective water management has been coupled with ecological assessment to provide systems that have the flexibility and robustness required in sensitive catchments.

Case Study Two
PROJECT: The Sidings, Baillieston, Glasgow
CLIENT: Barratt Homes West Scotland Limited
As part of our remit on this residential project DBA carried out extensive flood risk modelling of the Tollcross Burn which traverses the site. This included detailed hydrological and hydraulic modelling of the existing and proposed water corridor including a number of complex upstream and downstream culverts and overland flow paths which had a significant impact on flood hydraulics.

The existing modelling indicated that the vast majority of the site would be classed as functional flood plain. To allow development of the site DBA prepared detailed burn diversion and compensatory storage proposals. Post development hydraulic simulations confirmed that the development will have a neutral impact on existing hydrology and hydraulics of the area.

The proposed watercourse diversion was not solely based on hydraulic parameters, the design was also developed around ecological principles thus ensuring that existing habitat was maintained or enhanced as part of the proposals. These environmental considerations assisted greatly in achieving the necessary SEPA licensing approvals.

DBA also prepared detailed drainage and SUDS designs for the development which were holistically modelled to demonstrate compliance with relevant guidelines and policy.

Case Study Three
PROJECT: Westercraigs Development, Inverness
CLIENT: Robertson Group
DBA provided a comprehensive water management and hydro-ecology service for this 120 hectare mixed use development on the site of the former Craig Dunain Hospital.

The development includes the new Scottish Natural Heritage headquarters, refurbishment of the Victorian hospital buildings along with approximately 500 new residential dwellings and associated on and off site infrastructure.

In conjunction with the civil and structural engineering design for the roads and residential phases, the water management aspects of this project included ecological, hydrological and hydraulic assessment of the natural and urban catchments, preparation of drainage strategies, detailed design of best practice SUDS techniques, watercourse diversions, Controlled Activities Licensing and site supervision.

In partnership with the Centre for River Restoration Science at Stirling University, DBA prepared detailed designs for some 300 metres of geomorphologically sustainable burn diversion works and access footpaths designed to provide a range of restored local habitat and social opportunities within the development.

Case Study Four
PROJECT: Toryglen, Glasgow
CLIENT: Glasgow City Council
DBA carried out a strategic drainage feasibility study to investigate options that would allow redevelopment of the Glasgow urban district of Toryglen.

The study identified and assessed a number of sustainable and practical drainage strategies in close consultation with Glasgow City Council, SEPA and Scottish Water specialists.

Assessment of regional past and present drainage characteristics, constraints to drainage proposals including existing infrastructure and ground contamination, along with the possible affects of regional land use change, were carried out to identify a number of regional drainage strategy options.

Options included; SUDS source, site and regional control strategies, local upgrading of existing drainage infrastructure, strategic deep tunnel storm sewer scheme design, and above ground flood relief measures were considered. All identified options were measured in detail to provide bill of quantities and budget estimate costs for easy comparison between the options.

Case Study Five
PROJECT: M8/A8 Interchange, Bishopton
CLIENT: BAe Systems
DBA carried out a comprehensive Flood Risk Assessment and Surface Water Management Scheme for this strategic infrastructure project. The project was undertaken in close consultation with Renfrewshire Council, SEPA, Transport Scotland and BAA (Glasgow Airport).

The proposed scheme included specialist designs to mitigate existing water pollution arising from landfill leachate as well as watercourse diversions and restorations, bridging structures and SUDS treatment and attenuation wetlands.

The SUDS wetlands were designed to provide robust treatment whilst deterring large birds to manage risk of bird-strike to aircraft.

The Surface Water Management Scheme was designed to comply with the Water Environment (Controlled Activities) (Scotland) Regulations 2005 whilst meeting Adopting Authority requirements.

Case Study Six
PROJECT: Former Gas Works, Musselburgh
CLIENT: National Grid Property Holdings Ltd
Located close to the River Esk and the Firth of Forth coast our Client was seeking to obtain planning permission on the 0.9ha, potentially contaminated, brownfield site for residential development. DBA were appointed as water management consultants to support the design team.

In support of the planning application DBA prepared a detailed Flood Risk Assessment Report and Foul & Surface Water Drainage Strategy Report for the proposed development.

Given the coastal location the Flood Risk Assessment aspects of this project required detailed consideration of coastal flood processes including localised estuarine hydraulics, extreme tide prediction, residual surge effects caused by intense weather systems and climate change impacts.

The Foul & Surface Water Drainage Strategy Report addressed drainage constraints which could have potentially hindered development of the site. This was achieved by ensuring that foul flows from the development would have no detrimental impact on the receiving combined sewer system. The surface water strategy ensures that surface water runoff to the River Esk is managed in a sustainable manner utilising suitable SUDS methods which are incorporated into the development landscaping.

Case Study Seven
PROJECT: Gartloch Village, Glasgow
CLIENT: New City Vision Group
DBA were appointed as water management consultants for this flagship residential project in 2003 and have been providing our services since then ranging from master-planning feasibility through to detailed design and site supervision and monitoring.

The development site covers an area of some 40ha and is encompassed within the drainage catchment of the adjacent Bishop Loch SSSI which is a highly sensitive receiving water and ecological environment.

DBA are providing an ongoing water management consultancy service for the development including preparation of Drainage Strategy and Flood Risk Assessment Reports, detailed SUDS designs and legislatory licensing, hydraulic modelling, construction phase water quality testing and construction phase erosion and sediment control plans.

Given the sensitive nature of the receiving water environment the surface water discharges from the site were the first in Scotland that required formal licensing under The Water Environment (Controlled Activities) Regulations 2005.

Given the site specific constraints of this project, the detailed stakeholder engagement undertaken and the innovative SUDS methods applied the SUDS at Gartloch Village are now being showcased by Abertay University as a Case Study project under the European Interreg funded North Sea Skills Integration and New Technologies (SKINT) Project - www.skintwater.eu

Case Study Eight
PROJECT: Marchfield Development, Dumfries
CLIENT: Story Homes
DBA initially provided input to the masterplanning of this major residential and business development, covering an area of 99ha on the outskirts of Dumfries.

The development is constructed around an ecologically sensitive Local Nature Reserve, owned and managed by the Scottish Wildlife Trust (SWT), and in an area dominated by a highly sensitive groundwater aquifer and peat bog.

DBA successfully negotiated and demonstrated to Scottish Natural Heritage (SNH), SWT, SEPA, Dumfries and Galloway Council and Scottish Water, a practical solution to preserve the integrity of the Local Nature Reserve whilst allowing maximum development of the site.

To achieve this DBA carried out all necessary hydrological and strategic drainage assessments, leading to the detailed design of innovative surface water management solutions on a catchment scale along with regional SUDS treatment facilities and groundwater barriers to facilitate the removal of peat for residential development purposes.

The final surface water management solutions were designed in consultation with SNH, SWT and SEPA, eliminating the need for hard engineering between the SUDS and Local Nature Reserve to create new habitat and enhance biodiversity.

Case Study Nine
PROJECT: MetroCentre, Gateshead
CLIENT: - Capital Shopping Centres
DBA is providing the Client with Project Management and Engineering service for a drainage retrofit project at the MetroCentre Shopping Centre, Gateshead.

Proposals for the site include installation of a number of hydrodynamic vortex separators on the existing surface water drainage system which serves the complex. These systems will provide treatment of storm water run-off prior to discharge into a culverted watercourse which traverses the site, ultimately discharging to the River Tyne.

As part our remit DBA’s water management team organised and supervised detailed investigations across the site including drainage CCTV surveys and trial pit investigations.

Detailed retrofit designs were developed in close consultation with Centre Management and the Contractor to ensure that the construction works and long term maintenance would have a minimal impact on operations at the centre.

This project includes ongoing liaison with the Client and Contractor including regular site meetings and preparation of dilapidation and 'as-built' survey reports.