Can anyone recommend some good books on sustainable or "green" practices in the field of civil engineering. Also welcome are tips on other information resources such as web sites.
Too broad a question - are you writing an essay as part of an assignment or do you have a specific field of interest ?
My field is irrigation, water resources and river engineering. In this field environmental and economic sustainability are the primary factors considered in the development of any engineering solution. Sustainable Urban Drainage Systems (SUDS) are the current vogue:
I agree with BRIS, a big focus on sustainability in the civil field right now is stormwater management. Some of it is a great idea, others, well....I haven't completely bought into planting plants on the roof of my house yet.
In answer to your specific questions, there's a guy in Maryland (Larry Coffman) who does a lot of studies with respect to Low Impact Development, which has now become a trade name for his type of practices. Again, some of them are great, others are still great, but impractical.
I personally believe that treated wastewater reuse will be the next "big damn deal" with respect to water resources, but most of the public isn't ready for that yet.