Rob,
As an engineer in the UK with one years' experience, I was making ?19,000pa in London in 2000. That was the beginning of the shortage of engineers in the UK, particularly in London, and salaries did increase slightly subsequently. The best money was to be made contracting at around ?20-?25ph for people with key skills.
Three drainage plans is not extensive experience; it probably got you the job, but it won't win the company any work.
If you want to know what the current salary range is for drainage modellers with one year of experience, then you should look in trade magazines. The ICE magazine is a good place to start. Remember that salaries in the South West will be lower than those in London and Manchester or Birmingham. If you're using a recruitment agent, ask your agent; that's as much his or her job as getting you the interviews is. Prior to getting you the interview the recruiter would've inflated their salary estimate, but once you're in negotiation, they will be realistic because they don't want you to lose the job for asking for too much money.
Finally, don't sell yourself short, but be realistic. Engineers are not particularly well paid in the UK. Until I moved to a position with the DfT, the receptionist made more money than I did. (But I had money available to me for training.)
Another point to remember if you're using an agent is that the agent's commission is payable after you've been there for 3 months, and it's a substantial percentage of your annual salary. You can strike a deal with the employer to accept less for the first three months and more after the agent has received their cut. Do not mention this to your agent, however.
