Rural Flood Management SuDS Design

hi,

I need help discharging a planning condition. the planning condition is as follows:

"4. Prior to occupation, a scheme for the management of surface water must be provided to and approved by the LPA 1. Demonstration that FFLs of any habitable areas are at least 150mm above existing ground levels 2. Demonstration that the existing drainage system is adequately sized 3. CCTV survey of existing drainage system to demonstrate condition and details of any necessary remedial measures 4.Demonstration that discharge rates can be reduced through the use of Sustainable Drainage Systems. Reason: In the interest of managing surface water flood risk for the lifetime of the development and to ensure the development can demonstrate a sustainable and suitable surface water outfall. In accordance with NPPF (2024) Paragraph 182 and National Standards for Sustainable Drainage Systems (2025). Typical SuDS features for a scheme of this nature includes rainwater harvesting butts or downpipe SuDSplanters."

I have had a CCTV and sonar drain trace done, and I have had a an engineering company draw out the drainage plan, unfortunately the same engineering company also wrote a word-based SuDS strategy, which wasnt what the council wanted. i believe they want calculations and proof of the reduction of discharge rates compared to historic or perhaps brownfield rates. Im hoping that you can help me. i tried myseelf using AI, but i have no idea if this is right or not anyway! please help