Eskdale Stream Assessment
Summary of report findings
Development of the Eskdale Stream catchment has occurred mostly during the last 30-50 years, subsequent to the opening of the Auckland Harbour Bridge in 1959. The catchment contains a total of 18 reserves which together cover 26% of the catchment. The Eskdale Stream is one of the largest stream networks on the North Shore. The catchment contains areas with good riparian vegetation and little channel modification as well as some areas heavily modified by urban development. The stream receives significant inputs from the reticulated stormwater network within the catchment.
Documents
Eskdale Stream report PDF 
(1.79MB)
Eskdale Stream maps (PDFs)
Links
North Shore stream assessments overview page
You will need Acrobat Reader to view some documents on this page, which can be downloaded free from www.adobe.com
| Length |
15.2km |
|
| Size Of Catchment | 384ha | |
| Vegetation Cover | 42% (161ha), occurring along the stream channel though much of the catchment. | |
| Imperviousness | 23% | |
| District Plan Land Use | Business | 1% |
| Recreation | 26% | |
| Residential | 62% | |
| Road | 10% | |
| Recreational Use | Medium, some known public use of stream locality. | |
| Receiving Environment | Kaipatiki Creek, Hellyer (Oruamo) Creek, Upper Waitemata Harbour. | |
| Substrate | Predominantly silt/mud with deep sediment deposits in many tributaries. | |
| Natural Wetlands | 5 | |
| Artificial Wetlands | 1 | |
| Periphyton | Significant densities of diatomaceous algae in the main channel and Tributaries 1 + 9 (below nuisance levels), and at nuisance levels in Tributary 8. | |
| Macrophytes | Possible management issues in the upper main channel and Tributaries 1, 4 + 5B. | |
| Macroinvertebrates | Moderate to high %EPT + MCI values. | |
| Fish | 5 species of native fish + koura. | |
| Potential Man-Made Barriers to Fish Passage to Upstream Habitat | 11 (+ 8 potential natural barriers). | |
| Channel Modification | Limited modification, 25% of total channel length affected. Lower main channel 14% lined, upper main channel 5% piped, Tributary 1 17% piped, Tributary 5C 23% lined, and Tributary 6 23% piped. | |
| Erosion around Structures | More outfalls with erosion than any other stream surveyed. 19 structures with slight erosion, 7 with moderate erosion, and 5 with severe erosion. | |
| Bank Erosion | Predominantly slight (natural) erosion. Minor to moderate erosion in the tributaries with sections of severe erosion. | |
| Temperature | Winter temperatures recorded were low and indicate no adverse effect on steam ecology, however summer temperatures are likely to be higher. | |
| Suspended Solids, Turbidity And Visual Clarity | Approximately average suspended solids and turbidity levels. Average clarity throughout most tributaries, below average in the main channel and Tributary 5B. | |
| Oxygen and Oxygen Demand | Oxygen levels 8.7 and 4.5 g/m3 in the upper and lower main channel respectively. Low oxygen demand. | |
| Nutrients | Low ammonia + average nitrate concentrations. | |
| Contaminants | Typical compared to other North Shore streams, low zinc concentrations. | |
| Bacteria and Pathogens | Levels of indicator bacteria indicate the stream is not suitable for contact recreation. | |
| Sediment Quality | No data. | |
| Debris | Insignificant inorganic debris except for the head of Tributary 3. Moderate organic debris throughout due to the collapse of streamside vegetation, particularly in Tributary 7. | |
| Stream Grouping | Group 2, High value low disturbance | 65% |
| Group 3a, Urban semi-modified | 23% | |
| Group 3b, Urban modified | 3% | |
| Group 4, Concrete lined channel | 2% | |
| Group 5, Piped section | 7% | |