PROJECT | JBA were commissioned by Natural England to identify and appraise options to improve the condition of the Hull Headwaters SSSI at Lowthorpe. Background The headwaters of the River Hull are nationally important as the most northerly chalk stream system in Britain. Lowthorpe Beck is a tributary of the River Hull and part of the river’s headwaters. The river system is designated a Site of Special Scientific Interest (SSSI). Lowthorpe Beck has been modified at the site of a former mill at Lowthorpe village and this has had a negative effect on the habitat and morphology of the channel. Further upstream other changes to the watercourse have been made over time. It is these changes that have led to the SSSI being in ‘Unfavourable Condition’. What we didThe project was divided into three phases,

Phase 1 was an options appraisal into the feasibility of removing the weir at Lowthorpe. This involved a detailed engineering inspection of the weir and races as well as ecological and archaeological survey and Landscape Visual Assessment of the preferred option. This was taken forward by Natural England and used in public and stakeholder consultations.

Phase 2 was the detailed design of the preferred option, which involved the filling-in of the mill race, leaving the structure in-situ and bypassing through re-occupying the old channel of the Lowthorpe Beck. Then creating a new section to channel across a field to re-join the tail race channel upstream of a small bridge thereby avoiding the need to instruct a new bridge across the old beck channel.We did a detailed NVC ecology survey of the grasslands through which the new weir bypass channel as well as topographic survey and engineering design.

Phase 3 was the construction of the new channel by the East Yorkshire Rivers Trust in 2015.

Summary of Project Outcomes The project removed a physical barrier from the SSSI,

Lowthorpe Weir

Client, Stakeholders, Partners: Natural England, East Yorkshire Rivers Trust, local landowner and land managers.Location: Lowthorpe, Driffield, East YorkshireDate/Phase: 2012 to 2015Funding sources: Natural England, Environment Agency

Options appraisal

Stakeholder engagement

Detailed design

Construction

(Phase 1) (Phase 2) (Phase 3)

Schematic drawing of the Weir plan

allowing the river to re-occupy part of its former channel with the gravel bed still in-situ, creating a more natural planform and reconnecting it with its meanders and floodplain.The outcomes were:

• Fully costed options appraisal of three main options with two variations;

• Preliminary Ecological Assessment detailing the ecological benefits of each option;

• Cultural Heritage Assessment of each of the options and variations;

• Landscape Visual Assessment of the preferred option;

• Presentation material for use in public engagement events;

• Full detailed design taking into account the sensitivities of the site and the river;

• Partnership working and full stakeholder buy-in from the outset. Project Benefits The archaeology has been left in-situ rather than destroyed. Natural England and the East Yorkshire Rivers Trust are very happy with the outcome and the baseline conditions in the new reach were recorded in detail allowing any change to be quantified in future surveys. Effective working between the project partners and the lessons learned on this weir have since been employed on other weirs elsewhere on the Hull system.

Lessons learned • Early stakeholder engagement is essential aswell as communication on progress.

• Compromises can bring results and greater co-operation: this was demonstrated with the archaeology and the avoidance of having to construct a new bridge downstream. ContactKieran Sheehan: kieran.sheehan@jbaconsulting.com: or Matthew Hemsworth: matthew.hemsworth@jbaconsulting.com for more information see: LInk