Tanques de ferrocemento

The Texas Manual on Rainwater Harvesting

Texas Water Development Board
Third Edition

The Texas Manual on Rainwater Harvesting

Texas Water Development Board in cooperation with Chris Brown Consulting Jan Gerston Consulting Stephen Colley/Architecture Dr. Hari J. Krishna, P.E., Contract Manager Third Edition 2005 Austin, Texas

Acknowledgments
The authors would like to thankthe following persons for their assistance with the production of this guide: Dr. Hari Krishna, Contract Manager, Texas Water Development Board, and President, American Rainwater Catchment Systems Association (ARCSA); Jen and Paul Radlet, Save the Rain; Richard Heinichen, Tank Town; John Kight, Kendall County Commissioner and Save the Rain board member; Katherine Crawford, Golden EagleLandscapes; Carolyn Hall, Timbertanks; Dr. Howard Blatt, Feather & Fur Animal Hospital; Dan Wilcox, Advanced Micro Devices; Ron Kreykes, ARCSA board member; Dan Pomerening and Mary Dunford, Bexar County; Billy Kniffen, Menard County Cooperative Extension; Javier Hernandez, Edwards Aquifer Authority; Lara Stuart, CBC; Wendi Kimura, CBC. We also acknowledge the authors of the previous editionof this publication, The Texas Guide to Rainwater Harvesting, Gail Vittori and Wendy Price Todd, AIA.

Disclaimer
The use of brand names in this publication does not indicate an endorsement by the Texas Water Development Board, or the State of Texas, or any other entity. Views expressed in this report are of the authors and do not necessarily reflect the views of the Texas WaterDevelopment Board, or any other entity.

Table of Contents
Chapter 1 Introduction..................................................................................................... 1 Chapter 2 Rainwater Harvesting System Components................................................. 5 Basic Components.......................................................................................................... 5 The Catchment Surface................................................................................................... 5 Gutters and Downspouts ................................................................................................. 6 Leaf Screens.................................................................................................................... 7First-Flush Diverters ....................................................................................................... 8 Roof Washers................................................................................................................ 10 Storage Tanks................................................................................................................ 10Pressure Tanks and Pumps............................................................................................ 16 Treatment and Disinfection Equipment ........................................................................ 17 Chapter 3 Water Quality and Treatment..................................................................... 21 Considerations for the Rainwater Harvesting System Owner...................................... 21 Water Quality Standards ............................................................................................... 22 Factors Affecting Water Quality................................................................................... 22 Water Treatment........................................................................................................... 23 Chapter 4 Water Balance and System Sizing............................................................... 29 How Much Water Can Be Captured? ........................................................................... 29 Rainfall Distribution ..................................................................................................... 30 Calculating Storage...