Rural Stormwater Drainage System Design

I need a comprehensive design for a stormwater drainage system specifically tailored for a rural area. The design should effectively manage water flow and prevent flooding without incorporating any water quality treatment processes. Key requirements include: - Detailed drainage layout - Calculations for flow rates and drainage capacity - Consideration of rural terrain and vegetation - No water quality treatment processes like sedimentation basins or biofiltration systems Ideal Skills and Experience: - Expertise in civil or environmental engineering - Experience with stormwater management in rural settings - Proficiency in drainage design software - Strong understanding of hydrology and rural land development Please provide samples of previous similar work and a timeline for project completion. we have topographical survey of site, previous water drainage was designed to cross the road, but we have an area that was an old reservoir, that we can make in to an attenuation tank(shown in yellow). there is a river adjacent and there is already a spring entering the river at the same point(shown in red) also the carport on the design has moved. must be suitable for planning application and be chartered surveyor