HBC - Aberford Park Brook Improvement

Description

Hertsmere Borough Council ("the Council") seeks quotations from suitably experienced and competent contractors to undertake the design, permitting and implementation of brook and lake improvement works within Aberford Park, Borehamwood, Hertfordshire. The watercourse within Aberford Park forms part of Tykes Water and receives surface water runoff from surrounding roads and residential areas. At the head of the brook is an oil interceptor, originally installed to prevent pollution from Borehamwood's historic industrial activities. The interceptor has since been decommissioned by the Environment Agency as surrounding land uses have changed and are now predominantly residential, office and light industrial. Surface water currently bypasses the interceptor and discharges directly into the lake. Major restoration works were undertaken in 1999 and 2008, including desilting, reprofiling, fountain installation and refurbishment, and planting works. The Council understands that sediments removed during these works were retained and beneficially reused within the site. Approximately eighteen years have elapsed since the last major intervention. The Council has identified a number of issues requiring remediation: • Increased silt accumulation resulting in reduced lake depth; • Malfunctioning fountains due to sediment accumulation; • Algal blooms and associated odours during summer months; • Excessive reed growth resulting from low flows and seasonal water level variations.