---
title: "Flow Rate Calculations for Rationing"
canonical: "https://docs.rubiconwater.com/space/PNC/2051900069/Flow%20Rate%20Calculations%20for%20Rationing"
format: markdown
---
> Macro (toc)

# River Water Flow Rate Calculations

The way that river flow rates are calculated depends on the Participation mode of the planning area and the orders.

> ℹ️ **Note**
> ℹ️ 
> ℹ️ The number of decimal places used to express flow rates is controlled by the Order Flow Rate Decimal Places attribute. See [https://rubiconwater.atlassian.net/wiki/spaces/PNC/pages/2051866942](https://rubiconwater.atlassian.net/wiki/spaces/PNC/pages/2051866942) for details.

## Participation Mode: *Exclude*

River flow rates affected by a restriction are based on the **Date Last Restriction** attribute of each property. Properties are ranked in order of their last restriction date and the full ordered amount is delivered to each property starting with the one most recently restricted (note that where properties have been restricted for several day in a row, the duration of the restriction is taken into account). When there is not enough water to deliver the next full order, no further orders are delivered.

**Example:**

Suppose we have three properties A, B, and C in the same water restriction group with Participation mode of *Exclude*. They all have a flow share of 1. The orders require a total of 30 ML/d of river water.

**Restrict the supply of river water to 12 ML/d.**

|  | **A** | **B** | **C** |
| --- | --- | --- | --- |
| Ordered ML/d> | 10 | 10 | 10 |
| Date Last Restriction | Jan 1 | Jan 2 | Jan 3 |
| River water delivered | 0 | 0 | 10 |

## Participation mode: *Restrict*

River flow rates for orders affected by a restriction are based on the share allocated to the affected properties.

> ℹ️ **Note**
> ℹ️ 
> ℹ️ The share of the flow allocated to each property is set in an attribute. You can specify which attribute you want to use to store this share value, but the default attribute is the *Flow share*. See [https://rubiconwater.atlassian.net/wiki/spaces/PNC/pages/2051900084](https://rubiconwater.atlassian.net/wiki/spaces/PNC/pages/2051900084) for more details.

When a flow restriction is applied at a regulator, the following calculations are made for affected orders downstream:

1. The proportion of the total flow available for each property is calculated from the property flow share attribute.
2. If the orders for a property do not exceed its share of the available flow, the order is unchanged and the property receives the flow that it ordered. Any additional flow that the property is entitled to, but does not need, is added to the flow available to other properties.
3. The calculation is repeated, excluding the properties that do not exceed their flow entitlement until the allocated flow for each property has been calculated.
4. If a property has orders for more than one outlet, the flow allocation for that property is delivered to those outlets in proportion to the original requested flow rate.

**Example**

Suppose we have two properties A and B in the same water restriction group. A has a flow share of 1, and B has a flow share of 2. The orders require a total of 20 ML/d of river water

**1.Restrict the supply of river water to 12 ML/d**

|  | **A** | **B** |
| --- | --- | --- |
| Flow share | 1 | 2 |
| Percentage of total flow share | 33% | 67% |
| Ordered ML/d> | 10 | 10 |
| Maximum share of 12 ML/d | 4 | 8 |

Both orders are restricted.

**2.Restrict the supply of river water to 15 ML/d.**

|  | **A** | **B** |
| --- | --- | --- |
| Flow share | 1 | 2 |
| Percentage of total flow share | 33% | 67% |
| Ordered ML/d> | 10 | 10 |
| Maximum share of 15 ML/d | 5 | 10 |

Order B is not restricted because the ordered flow rate does not exceed B’s share of the flow and there is enough flow available to fully supply B. A has a smaller share of the flow, so A is restricted.

**3.Restrict the supply of river water to 20 ML/d.**

|  | **A** | **B** |
| --- | --- | --- |
| Flow share | 1 | 2 |
| Percentage of total flow share | 33% | 67% |
| Ordered ML/d> | 10 | 10 |
| Maximum share of 15 ML/d | 5 | 10 |

Neither order is restricted because there is enough water available to supply both orders

## Participation Mode: *Restrict*, with Individual Orders *Exclude*

In this case, any fully delivered orders are allocated first and the remaining water is shared based on the Flow Share of the other properties.

**Example**

Suppose we have three properties A, B, and C in the same water restriction group with Participation mode of *Restrict*. They all have a flow share of 1. The orders require a total of 30 ML/d of river water.

**1.Restrict the supply of river water to 12 ML/d.**

|  | **A** | **B** | **C** |
| --- | --- | --- | --- |
| Ordered ML/d> | 10 | 10 | 10 |
| River water delivered | 4 | 4 | 4 |

**2.Now set order A to *****Exclude***** to receive the requested rate:**

|  | **A** | **B** | **C** |
| --- | --- | --- | --- |
| Ordered ML/d> | 10 | 10 | 10 |
| River water delivered | 10 | 1 | 1 |

# Restriction Intervals - Refining the Flow Restriction

A flow restriction may be divided into intervals and the calculations are repeated for each interval. This allows for the possibility that the order balance may vary during the period of the flow restriction so the optimal flow share may change.

# Stored Water Volume Calculations

A restricted order may or may not be topped up depending on the preference of the customer. When a customer places an order, they have the option to set the **Volume Reduction Percentage** that they will accept for the order. This value sets the percentage of the original order volume that they are prepared to accept without topping the order up.

If the total volume supplied for an order is within their acceptable limits, no topup is required. Otherwise, the order is topped up to meet their limit provided they have stored water available. The topup is applied by increasing the flow rate on the rationing day to offset some or all of the rationing.

If the customer does not set the Volume Reduction Percentage, it defaults to zero which means that the order will not be topped up with stored water.

**Example**

Suppose an order has been placed for 10 ML/d of water for two days. For one of those days, a rationing plan is in place that reduces the flow for the day to 5ML/d

**1.If the *****Volume Reduction Percentage***** is not set, or is set to 0%.**

|  |  |
| --- | --- |
| Original order volume | 20 ML |
| Restricted order volume | 15 ML |
| Percent of ordered volume | 75 % |
| Top up volume | 0 ML |
| Final order volume | 15 ML |

No top up is required because the customer is prepared to accept any restriction applied.

**2.If the *****Volume Reduction Percentage***** is set to 80%.**

|  |  |
| --- | --- |
| Original order volume | 20 ML |
| Restricted order volume | 15 ML |
| Percent of ordered volume | 75% |
| Top up volume | 1 ML |
| Final order volume | 16 ML |

The order is topped up to bring the final volume to 80% of the ordered volume.

**3.If the *****Volume Reduction Percentage***** is set to 100%.**

|  |  |
| --- | --- |
| Original order volume | 20 ML |
| Restricted order volume | 15 ML |
| Percent of ordered volume | 75% |
| Top up volume | 5 ML |
| Final order volume | 20 ML |

The order is topped up to the original ordered level.

---