Source: https://tendernation.io/opportunities/01a13bbf-d082-7249-bd09-78600da30265/investigation-of-regulated-tidal-exchange-and-water-level-control-structures-for awarded GB open procedure Suitable for SMEs # Investigation of regulated tidal exchange and water level control structures for management of saline lagoons at North Killingholme Haven Pits Site of Special Scientific Interest, North East Lincolnshire [Natural England](https://tendernation.io/buyers/natural-england) Estimated value £5,600 Published 2 Sept 2025 Deadline Closed 13 Aug 2025 ## Who can bid - Buyer says suitable for SMEs The buyer ticked “suitable for SMEs” on the notice. Anyone can still bid. - Below-threshold contract Buyers cannot shortlist bidders on suitability before tenders are in, so everyone gets to submit a bid (except some larger works contracts). [Procurement Act 2023, section 85](https://www.legislation.gov.uk/ukpga/2023/54/section/85) - Open procedure Anyone can submit a full tender; there is no shortlisting stage. [More contracts for small businesses and VCSEs](https://tendernation.io/opportunities/for-small-businesses) ## About this tender North Killingholme Haven Pits SSSI is near Immingham, North East Lincolnshire, on the south bank of the Humber Estuary (central grid reference TA1662919816). The privately owned,16ha, site comprises former clay pits which have developed into saline lagoons. It is within the Humber Estuary Special Protection Area/Ramsar site and is of international importance for non-breeding waterfowl. The site is connected to the Humber Estuary by a manually operated sluice in the flood bank, which allows for the regulated exchange of tidal water. The sluice is over 50 years old and is not fully functioning due to siltation, and health and safety concerns regarding its operation. The aims of the investigation are to survey the existing water level control structures on site, and appraise the options for management of water levels to achieve the site objectives. Outputs include a levels survey, concept designs and estimated costs for each option and associated actions. Site surveys are required. Technical and practical expertise is required. This is difficult terrain due to tidal mudflats and open water. There is also a working railway line. A site-based risk assessment will be required to be submitted to Natural England. Contract to start 1 September 2025, with final report to be submitted by 1 March 2026. ## CPV classification Environmental services Source Find a Tender (UK) · Notice ocds-h6vhtk-05644a-2025-09-02T08:50:24+01:00 [View official notice](https://www.find-tender.service.gov.uk/Notice/ocds-h6vhtk-05644a-2025-09-02T08:50:24+01:00) Never miss a tender like this again Get AI summaries, deadline alerts and a bid pipeline for tenders matched to your business. Free to start. [Track tenders free](https://tendernation.io/register) [Buyer profile Natural England: past awards and live tenders](https://tendernation.io/buyers/natural-england) [Sector More Sewage, refuse, cleaning & environmental tenders](https://tendernation.io/sectors/sewage-refuse-cleaning-environmental) ## More tenders like this [SHWD Cleaning · South Hams District Council · 32 days left · 20 Nov 2026](https://tendernation.io/opportunities/01a15552-1e5c-7112-a772-bb30d175a2ae/shwd-cleaning) [Pest Control Services · Yorkshire Housing Limited · 28 days left · 16 Nov 2026](https://tendernation.io/opportunities/01a15552-1ecb-72eb-99a2-28725729b3f4/pest-control-services) [Pest Control Services Concession 2027-30 (FH2610191) · The District Council of Folkestone and Hythe · 29 days left · 17 Nov 2026](https://tendernation.io/opportunities/01a154e4-44f9-7309-afae-daba3a678a46/pest-control-services-concession-2027-30-fh2610191) [Invitation to Tender Window Cleaning Services - Wirral · Wirral Community Health and Care NHS Foundation Trust · 32 days left · 20 Nov 2026](https://tendernation.io/opportunities/01a1539a-cf1d-702b-9ffd-93cfa91d3c7c/invitation-to-tender-window-cleaning-services-wirral) [Refuse transport services – Odbiór odpadów komunalnych z terenu miasta Maków Mazowiecki · Miasto Maków Mazowiecki · 35 days left · 23 Nov 2026](https://tendernation.io/opportunities/01a15183-3f12-7325-9c2f-18eb44993615/poland-refuse-transport-services-odbior-odpadow-komunalnych-z-terenu-miasta) [Cleaning services – Úklidové služby pro budovy JP · České vysoké učení technické v Praze · 15 days left · 3 Nov 2026](https://tendernation.io/opportunities/01a15183-4b75-72e0-8073-c7b65b5d95d9/czechia-cleaning-services-uklidove-sluzby-pro-budovy-jp)