Urchfont Pond Planting and fish removal proposal June

Urchfont Pond Planting and fish removal proposal June 2020

Introduction and background • Planting the Pond is the second and final phase of the pond water quality improvement project presented at the Pond Forum last year. • 50+ parishioners attended the forum and the vast majority were in favour of planting the pond. In fact there were calls to plant the pond immediately • MB receives frequent requests “when are we going to plant the pond? ” • It was decided to approach the improvement of the water quality in two phases. Phase one, now complete, was to get the water quality to a standard that would support planting. • Nothing had been done to the pond for 20+ years, whilst increasingly hot summers and ever increasing levels of nutrients in the pond had resulted in frequent algal blooms. • Some attempts had been made to plant the pond and had failed • Previous proposals to plant the pond “properly” had been rejected. • The result is blue green algae which has multiplied to reportable levels and still has minor blooms.

Objectives of the planting project • Improve the water quality so that it is safe and warning signs can be removed • Use planting to improve the aesthetics of the pond and introduce a natural water-quality control mechanism that is robust and can cope with the effect of climate change particularly hot, bright, dry weather. • Create a habitat for aquatic flora and fauna that is missing at the current time. • The pond is devoid of all aquatic life apart from fish, the urea from which pollutes the pond. • The fish are bottom feeders and constantly stir up the silt releasing phosphates • Maintain Urchfont Pond as the quintessential centre of the Parish.

What has been achieved so far • Ammonia level reduced to 0. 1 mgl – plants can now survive in the …. . • Reduced algal blooms – 1 st June to 4 th June 2020 small algal bloom successfully dispersed by 5 th June. Without the remedial actions taken to date there would have been a major bloom with a thick carpet of algae. 2020 so far - only year without red algae bloom since 2018 – minor BGA bloom currently. • Pond oxygen levels have been stabilised and prevent stagnation as algae die and produce CO 2 • Blue Green Algae recorded by Bernice Brewster at 100, 000+ cells per millilitre at the outset. Last measurement was 25, 000 cells per millilitre, still 5000 cells per millilitre over safe limit. 75% improvement. • Ammonia reduced to 0. 1 mgl safe level for planting. • Reduced silt and trapped phosphates.

Fish and Electro fishing • No one realised just how many fish there were in the pond. 1500 were removed by electro fishing on 14 th May. • The contractor estimates there are in all probability between 1000 to 1500 more fish in the pond all adding to the nutrient load. • Bernice Brewster commented “wow no wonder you’ve had problems in the pond” • Bernice advised that the balance should be removed ASAP. • Fish produce ureic acid = ammonia • Fish stir up the silt and release nutrients = bad news • Fish will spawn – the numbers will increase – the ammonia levels will increase providing yet more nutrients for the BGA

Planting the pond – Why? • We have been unable to reduce the BGA count in the pond to a non-reportable level having tried all alternatives • Aquatic Management Services, JPR Environmental, WLS Group, Frog Environmental, P&D Environmental all agree that planting is the only solution. • Bernice Brewster advised us from day one that the ultimate solution was to plant the pond once the water quality was satisfactory , which it now is.

Planting the pond – How? Pre-planted Coir Rolls • Coir rolls require a constant water level – our pond fluctuates by 400 mm the coir rolls are only 300 mm in depth • Originally we thought 1 length of 40 metres was required. To absorb enough nutrients to keep the BGA within limits 3 lengths would be required • The maximum water depth for the suspension method ( wooden poles and brushwood faggots ) is 750 mm. The pond is deeper than this. • We are advised that the cost of 3 x 40 metre rolls plus the support structure and lengthy installation (3 days) would be prohibitive. • Companies would not quote because the solution would not work for Urchfont pond.

Planting the pond – How? Submerged plants in baskets • This method has been used in Urchfont pond on a previous occasion and unfortunately it did not work • The method does not meet the aesthetic objectives we have for the pond • We would have to stop putting dye in the pond to enable the plants to get enough light. The dye is currently our go to defence mechanism against the BGA. • This method would not enable the aquatic ecosystem that we want to create. • This would be the ducks’ favourite

Planting the pond – How? Floating Islands Frog Environmental WLS Group • Designed as a 40 metre X 1 metre floating island that is anchored against the wall – not to it. • They rise and fall with the seasonal changes in water level. • They arrive pre-planted with plug plants that grow vigorously • Some are designed for DIY installation • Meets the aesthetic objectives • They have duck proof fences. • Planting schemes are designed to deliver algae beating water quality and a diverse aquatic ecosystem whilst looking stunning – flowering from May until September. Some evergreen plants can be included • Virtually maintenance free – the annual die back rots down and forms a seedbed enabling the plants to reproduce and replace older plants.

Cost Proposals • • Background Annual operating budget Electro Fishing Planted floating islands

Cost estimates from The Pond Forum Frog Environmental WLS Group • At the pond forum we stated that dredging the pond would cost £ 10, 000 to £ 20, 000 plus disposal of the silt and planting the pond. • We stated that estimates to plant the pond were in the region of £ 10, 000 but the budget would need to be reviewed. • In July 2019 P&D environmental quoted £ 12, 933 to install one length of coir roll • The costs associated with fish removal are a new component

2020 -2021 Running costs • Dye • Bacteria • Siltex • Testing kit • Full water tests • Annual review • Total £ 350 £ 316 £ 70 £ 130 £ 350 £ 1, 566 • Proposed budget request £ 1, 600

Electro fishing Proposal • Aquatic Management Services can remove as many of the remaining fish as possible on Friday 12 th June • The fish will be rehomed in the Cotswold Wildlife Park • The cost of removing the fish including rehoming is £ 700 • The residual fish population will require ongoing management – a consideration for future UPC budgets

Cost of floating islands Frog Environmental WLS Group • Costs (ex VAT) include floatation system, plants, anchoring system, duck fences and installation and are subject to final ratification. • Aquatic Management Solutions £ 12, 500 (use Frog environmental products) • WLS Group £ 9, 112 (only produce 2 m x 2 m modules ) • Frog environmental £ 8, 550 plus delivery • Proposed project budget £ 9000 + 10% contingency = £ 9, 900

Cost Summary Operating Costs • Operating budget £ 1600 Project Costs / Budget • Fish removal £ 700 • Pond Planting £ 9, 900 • Total project budget £ 10, 600 (vs original estimate of £ 10, 000 which did not include the cost of fish removal)