Use of Blaney-Criddle Reuse Water Balance Model

• File Number: 8461.250
• Description: Water Issues
• State: CO
• Basin: South Platte
• Water Division: 1
• Date: 7/28/1998
• Author: Unknown
• Title: Use of Blaney-Criddle Reuse Water Balance Model
• Water Supply Pro - Doc Type: Report/Study

Explanation and Use of the Blaney-Criddle Water Balance Model
July 28, 1998
Page 4
Below the three main data entry blocks is the final water balance tabulation area.
Within this final water balance tabulation area is an additional data entry area. This is where the
monthly precipitation values are entered.
An excerpt of the water balance tabulation area is copied below showing the precipitation input
area.
Rainfall inches
per month:
0.82
0.71
0.83
0.38
0.15
0.12
0.88
1.27
0.79
0.57
0.58
0.96
CALCULATIONS:
There are two main parts to the calculations performed in the spreadsheet. So far only the
Blaney-Criddle water balance calculation has been mentioned and described. In addition to this,
the spreadsheet is designed to estimate the water starage needs for the facility involved in
consumptive use irrigation. This part of the spreadsheet is only an estimate and is not intended to
be a design calculation. A professional engineer needs to be consulted to design and evaluate the
facility storage needs.
WATER BALANCE:
The water balance calculations sum: 1. (water available) the monthly effluent flow
and the average monthly precipitation, and 2. (water usage) the average monthly
evaparation, the monthly total pond leakage if allowable and approved by the
Department, the monthly turf consumptive use, and the monthly tree consumptive
use. An example of the water balance calculation block is on the next page.