Term Contract for Maintenance Dredging of the River Parrett: winter 2025/26 to 2029/30

The Parrett Internal Drainage Board (PIDB) (a member of the Somerset Drainage Boards Consortium (SDBC)) is acting on behalf of Somerset Rivers Authority (SRA) to commission a five-year term contract for annual dredging works on tidal reaches of part of the Rivers Parrett and Tone in Somerset to retain the conveyance capability achieved as a result of pioneer dredging by the Environment Agency following extensive flooding in the catchment during winter 2013/14.

An annual work schedule will be prepared for each year that funding is available on nominated reaches of the river(s) to be dredged. The 2025/26 schedule comprises a reach of approximately 4.8km of the River Parrett, downriver of Burrowbridge, Somerset, UK, as detailed in the example contract drawings included for tender quotation only (actual quantities will be assessed later this year for delivery winter 2025/26. Recent trend data indicates that this will involve dispersal of approximately 25,000m3 of silt.

Works are to be conducted in accordance with a Public Sector Cooperation Agreement between SDBC and EA and the 'River Parrett Water Injection Maintenance Dredging - Environmentally Acceptable Protocol' that currently restricts working in the rivers to the period 01 December to 28 February, and to the use of water injection dredging methods within the main channel following a course along the river thalweg such that mobilised sediment deposits are dispersed on ebb tides i.e. not removed to land from the river and targeted mechanical removal of excess material from the upper banks using an excavator (our preferred method is for this to be a water mounted operation working in tandem with the WID).

I am pleased to issue tender documents for the contract for your consideration. The conditions of contract will be the NEC Engineering and Construction Short Contract, Third Edition with additional Z clauses.

Kindly notify your intention to tender in advance of any submission and within 1 week of this notice being published. Your completed tender submission (completed Contractor's Offer, priced activity schedule, method statement, equipment specification and proposed contract starting and completion dates) should be returned by noon on the date specified in the tender documentation.

Tenders will be assessed on the basis of price (60%) and quality (40%) in line with the attached Tender Quality Assessment (TQA). The TQA requires an overall method statement and a detailed description of the proposed process and equipment specification, including anticipated productivity in m3/day/hr. These will be scored against the criteria indicated in the TQA.