Namoi River
Water Quality and River Flow Objectives

| Contents | Background | Consultation | Objectives | WQOs | RFOs | Glossary | Bibliography| Map | At a Glance |



This section gives the Water Quality Objectives (WQOs) and the River Flow Objectives (RFOs) for the Namoi River catchment, which should be used by the Namoi River Regulated, Unregulated and Groundwater Management Committees and others to develop plans and actions affecting water quality and river health. Only the priority RFOs are listed in this section, but the remaining objectives still need to be considered when developing flow management plans or dealing with particular local river conditions.

Town water supply subcatchments

The streams in town water supply subcatchments typically feed into a town water supply storage. In some cases the catchment may be declared specially protected to minimise the effects of land use on water quality.

Map: This category applies to streams running through areas coloured light blue on the map.

Top of PageWater Quality Objectives

Protection of:

Aquatic ecosystems

Visual amenity

Drinking water-Disinfection only

Drinking water-Clarification and disinfection

Drinking water-Groundwater

Top of PageRiver Flow Objectives

Protect pools in dry times

Protect natural low flows

Maintain wetland and floodplain inundation

Manage groundwater for ecosystems

Minimise effects of weirs and other structures

Top of PageSupporting information

Mainly forested areas

Streams in mainly forested areas are often valued for their conservation or recreational values. They usually have relatively natural flows and water quality. Many are in national parks or state forests. Other forests are generally in the upper areas of catchments.

Map: This category applies to streams running through areas coloured green on the map (state forests, national parks and nature reserves); and through other forested areas, if any are defined locally.

Top of PageWater Quality Objectives

Protection of:

Aquatic ecosystems

Visual amenity

Secondary contact recreation

Primary contact recreation

Drinking water at point of supply-Disinfection only

Drinking water at point of supply-Clarification and disinfection

Drinking water at point of supply-Groundwater

Aquatic foods (cooked)

Top of PageRiver Flow Objectives

Protect pools in dry times

Protect natural low flows

Manage groundwater for ecosystems

Minimise effects of weirs and other structures

Supporting information

Waterways affected by urban development

Waterways within urban areas are often substantially modified and generally carry poor-quality stormwater. Local communities are often keen to see these waterways returned to more natural conditions.

Map: These areas are shown as orange dots on the map.

Top of PageWater Quality Objectives

Protection of:

Aquatic ecosystems

Visual amenity

Secondary contact recreation, as a short-term objective, within 5 years

Primary contact recreation: assess opportunities to achieve as a longer term objective, 10 years or more

Top of PageRiver Flow Objectives

Protect pools in dry times

Protect natural low flows

Maintain natural rates of change in water levels

Minimise effects of weirs and other structures

Supporting information

Uncontrolled streams

These include all uncontrolled waterways that are not in the other categories. Their flow patterns are largely natural. Flows can occur in these streams from local runoff. They are typically ephemeral (flowing only during floods and freshes). Frequently, they open into or flow through wetlands and billabongs.

Map: Uncontrolled streams are shown as blue lines on the map.

Top of PageWater Quality Objectives

Protection of:

Aquatic ecosystems

Visual amenity

Secondary contact recreation

Primary contact recreation

Livestock water supply

Irrigation water supply

Homestead water supply

Drinking water at point of supply-Disinfection only

Drinking water at point of supply-Clarification and disinfection

Drinking water at point of supply-Groundwater

Aquatic foods (cooked)

Top of PageRiver Flow Objectives

Protect pools in dry times

Protect natural low flows

Protect important rises in water levels

Maintain wetland and floodplain inundation

Manage groundwater for ecosystems

Minimise effects of weirs and other structures

Supporting information

Major regulated rivers

These rivers have large dams supplying irrigation water (and some town and industrial water) for substantial distances downstream. Flows are typically supplemented during the irrigation season, resulting in fairly stable and unnaturally high water levels. River flow is substantially reduced during non- or low-irrigation seasons. At any time of year in periods which would normally have high or very high flow, flows may be substantially reduced by the trapping of water in a large dam.

Map: These rivers are shown as yellow lines on the map.

Top of PageWater Quality Objectives

Protection of:

Aquatic ecosystems

Visual amenity

Secondary contact recreation

Primary contact recreation

Livestock water supply

Irrigation water supply

Homestead water supply

Drinking water at point of supply-Disinfection only

Drinking water at point of supply-Clarification and disinfection

Drinking water at point of supply-Groundwater

Aquatic foods (cooked)

Top of PageRiver Flow Objectives

No RFOs were recommended in 1999, because Environmental Flow Rules had been adopted for the regulated river. In 2004, a Water Sharing Plan (WSP) commenced for the regulated Namoi River, including environmental water provisions. In general, the RFO framework should be considered when the WSP is reviewed under the Water Management Act.

Top of PageSupporting information

Controlled rivers with reduced flows

This category covers two cases:

1. River reaches downstream of the regulated sections where the water is extracted or diverted. Flow is generally reduced throughout the year. Water is delivered from the main stream for stock, domestic, some irrigation, and town water supplies several times a year.

2. Sections of rivers immediately below town water supply dams, where water is diverted directly from the dam. Flows can be substantially reduced throughout the year, though special environmental releases may be possible.

Map: These rivers are shown as red lines on the map.

Top of PageWater Quality Objectives

Protection of:

Aquatic ecosystems

Visual amenity

Secondary contact recreation

Primary contact recreation

Livestock water supply

Irrigation water supply

Homestead water supply

Drinking water at point of supply-Disinfection only

Drinking water at point of supply-Clarification and disinfection

Drinking water at point of supply-Groundwater

Aquatic foods (cooked)

Top of PageRiver Flow Objectives

Protect pools in dry times

Protect natural low flows

Protect important rises in water levels

Maintain wetland and floodplain inundation

Mimic natural drying in temporary waterways (including wetlands)

Maintain natural flow variability

Maintain natural rates of change in water levels

Manage groundwater for ecosystems

Minimise effects of weirs and other structures

Minimise effects of dams on water quality

Supporting information

This page was published 1 May 2006

|