UK Compliant Drainage Design Project

I need a drainage design creating for 2 properties. It needs to comply fully with UK building control regulations and must satisfy the local water authority. It needs hydro modelling to demonstrate it's compliance with the regulations and advice as the the best solution for our specific site... (Budget: £250 - £750 GBP, Jobs: 3D Modelling, AutoCAD, Building Architecture, Building Regulations, Civil Engineering, Construction Management, Environmental Engineering, Geotechnical Engineering)