Lignite Stream assessment
Summary of report findings
Originally noted by European settlers for its fine specimens of kauri (up to 6 foot in diameter), the Lignite Stream catchment still retains a significant area of bush cover (33%) and otherwise contains predominantly low density residential (33%) and rural land use (22%). Future development of the area is anticipated to involve conversion of 15% of the catchment currently in bush to low density residential use, and development of a further 1% of the catchment in bush for additional rural use. The stream retains considerable natural character and native riparian vegetation with minimal erosion and weed infestation.
Documents
Lignite Stream report PDF 
(1.63MB)
Lignite Stream maps (PDFs)
Links
North Shore stream assessments overview page
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| Length |
5.7km |
|
| Size Of Catchment | 191ha | |
| Vegetation Cover | 49% (94ha), in the northern and central catchment. | |
| Imperviousness | 17% | |
| District Plan Land Use | Business | <1% |
| Recreation | 18% | |
| Residential | 47% | |
| Road | 11% | |
| Rural | 23% | |
| Recreational Use | Low, no significant known public use. | |
| Receiving Environment | Upper arm Hellyers (Oruamo) Creek, Upper Waitemata Harbour. | |
| Substrate | Predominantly bedrock. Silt/mud Tributary 2 resulting from bank erosion. | |
| Natural Wetlands | Nil. | |
| Artificial Wetlands | Nil. | |
| Periphyton | Below nuisance levels. | |
| Macrophytes | No significant densities or management issues. | |
| Macroinvertebrates | No data. | |
| Fish | 7 species of native fish + koura. | |
| Potential Man-Made Barriers to Fish Passage to Upstream Habitat | 1 (+ 5 natural potential barriers). | |
| Channel Modification |
Nil. |
|
| Erosion around Structures | 3 structures with slight erosion, 4 with severe erosion. | |
| Bank Erosion | Slight throughout the majority of the stream, moderate erosion in Tributary 2, and minor in Tributary 1. | |
| Temperature | No data. | |
| Suspended Solids, Turbidity And Visual Clarity |
Suspended solids 3 - 24 g/m3, NTU 6.7 - 12, overall clarity average relative to other North Shore streams. |
|
| Oxygen and Oxygen Demand | Oxygen demand below detection levels (<2.0g/m3). | |
| Nutrients |
0.02 and 0.04 g/m3 ammonia, nitrate 0.184 and 0.257mg/l. |
|
| Contaminants | Typical of North Shore streams, low zinc. | |
| Bacteria and Pathogens | Levels of indicator bacteria indicate the stream is not suitable for contact recreation. | |
| Sediment Quality | No data. | |
| Debris |
Moderate organic debris in Tributary 2, otherwise no significant debris. |
|
| Stream Grouping | Group 2, High value low disturbance | 84% |
| Group 3a, Urban semi-modified | 13% | |
| Group 3b, Urban modified | - | |
| Group 4, Concrete lined channel | - | |
| Group 5, Piped section | 2% | |