The Rainwater Collection Calculator was created to assist in building a rainwater catchment system. Instructions on how to use the tool as well as the basis for all calculations will be presented here.
Creators
Created by Daniel Cobb with Mike Despars and Lonny Grafman.
Instructions
1) Enter your address in the following format '55555 Rainwater Lane, City, State, Zip' and click CENTER MAP to show your home.
2) Click on each corner of your home's roof. You must either go in a counter-clockwise or clockwise order when selecting each corner.
3) Click the GO button to see your rainwater catchment system specifications using default values.
4) Enter your information into the fields below the map in order to see more personalized data. All of these fields have default values and are therefore optional.
5) If a mistake is made you can click the RESET PAGE button to reset the map and all data fields.
6) In the list of specifications click the graph link to see a physical representation of the data.
7) To change the units from standard to metric simply click (units : US) found at the top of the list of outputs.
Dynamic Map
The dynamic map was modified from the version found on http://save-the-rain.com/world-bank/. This map is coded using the GoogleMaps API. We chose to use a different data set for the rainfall data. We used the data provided by http://www.ncdc.noaa.gov/ghcnm/v2.php?.
Monthly Water Usage
The monthly water usage should be entered in gallons. Clicking on the autofill link will let you enter different usage amounts for each month. With autofill on it will assume that you use the same amount each month. We assumed that the average US person uses 3000 gallons per month. This assumption was made from data provided by http://www.epa.gov/WaterSense/pubs/indoor.html.
Tank Size
If you currently have a storage tank or know what size tank you will be using enter the size of the tank. Once entered the output data will automatically update to your specification.
Tank Distance
This is the distance from your first flush to the storage tank. This will help determine the pipe size required for your system.