Technical reports 2008

TR2008/001 Exotic fish in ARC lakes
(330.2 KB PDF)

This report explores the impact exotic fish may have in lakes in the Auckland region, particularly water clarity, and recommends options for restoration.

TR 2008/002 Classification of Auckland urban streams
(1.5 MB PDF)

This report advocates a classification of urban streams based on 12 biological objectives and eight stream types. The information has been used to support ARC’s development of an urban stream management framework.

TR 2008/003 Exotic fish impacts in Lake Wainamu
(433.1 KB PDF)

This report identifies the impact exotic fish has had on biodiversity and water quality at Lake Wainamu and recommends that further investigations on the causes of high turbidity are investigated (TP274).

TR2008/005 Saline Water Quality State and Trends in the Auckland region
(1.6 MB PDF)

Monitoring of saline water quality has been undertaken for more than 15 years at 27 sites within the Auckland region. This report describes the state and long term trends in water quality for Auckland's marine environment.

TR2008/006 Kawau Bay
(1.8 MB PDF)

This report explores the Benthic Marine Habitats and Communities of Kawau Bay

TR2008/008 Marine Water Quality Data Report 2006
(1.4 MB PDF)

An annual summary of water quality data collected from 27 marine locations as part of ARC's comprehensive water quality monitoring network.

TR2008/10 State of the Environment Invertebrate Report
(849.3 KB PDF)

This report summarises and interprets the data resulting from the first five years of the ARC's freshwater invertebrate monitoring programme. The ecological state of the sites in the monitoring network is presented in relation to land use and habitat quality.

TR2008/011 Auckland Water Quantity Statement 2006/07
(1.7 MB PDF)

This is an annual series on the state of hydrology in the Auckland region and includes assessment of rainfall, stream flow, groundwater level & resource consent data for the twelve months June 2006 to May 2007.

TR2008/013 Upper Waitemata Harbour Ecological Monitoring 2005-2008
(1.2 MB PDF)

A long term monitoring programme was established in the Upper Waitemata Harbour in 2005, to monitor the ecological status of benthic macrofauna in habitats that have the potential to be affected by development of the surrounding catchments. This report summaries data collected so far (November 2005 - February 2008).

TR2008/014 - Papakura stream assessment and management study
(1.6 MB PDF)

This study was undertaken to quantify and assess the physical characteristics and ecological values of the waterways within the wider Papakura Stream Catchment, and to identify management options and prioritise activities that can maintain / improve the stream water quality and ecological values within that catchment. One of the main objectives of this study was to test the use of a combined River Environment Classification (REC) / Stream Ecological Valuation (SEV) approach to assist with Integrated Catchment Management Plans (ICMPs).

Additional note: this full report including appendices and the map series is available for purchase on CD.

TR2008/015 Beach Monitoring Report - Beach Profile Analysis
(1.8 MB PDF)

This report describes data collected from beach profiles located at 16 beaches in the Auckland region. These data span 10-20 years and represent long term monitoring of sand movement on beaches from the sheltered east coast to the more exposed west coast.

TR2008/016 Hunua ranges dams - freshwater fish survey 2008
(1.6 MB PDF)

This report presents the results of a joint ARC/Watercare Services Ltd survey of freshwater fish species in the four Hunua water-supply reservoirs (Mangatawhiri, Cosseys, Mangatangi and Wairoa).

TR2008/017 Central Waitemata Harbour Ecological Monitoring
(1.3 MB PDF)

This report details the results of a SoE monitoring programme for the Central Waitemata Harbour conducted between October 2000 and February 2008. The focus of the programme is to monitor the ecological status and trends of change in macrobenthic communities in the Central Waitemata.

TR2008/018 - Modelling Long-term Daily Sediment Loads to the Mahurangi Estuary
(490.0 KB PDF)

This report provides information describing predictions of daily and annual sediment yields to the Mahurangi Estuary for the period 1976 to 2002.

This report is part of a series of reports that were commissioned during the period 1993-1999 that were used to support the establishment of the Mahurangi Action Plan. They are being made available following a review of technical information.

TR2008/019 Benthic Ecology of Weiti Estuary and Karepiro Bay
(425.7 KB PDF)

This report details the results of a baseline quantitative benthic sampling of intertidal areas of Weiti Estuary and the subtidal and intertidal areas of Karepiro Bay. The design was to provide habitat and community information that would allow gross changes to be detected.

TR2008/021 - Performance of a Sediment Retention Pond Receiving Chemical Treatment
(2.7 MB PDF)

This report investigates the effectiveness of using a flocculent and coagulant chemical (PAC) to promote settling of fine sediment in sediment retention ponds. The investigation was conducted during the construction of the northern motorway. A pair of identical ponds were constructed, with one receiving flocculation and one not. Monitoring occurred between March and December 2007. Effectiveness (percentage) of sediment removal, quantity (mass) removed, and particle size removed were reported. The report provides information to determine the optimal conditions to maximize settling efficiency.

TR2008/022 Marine Sediment Core Profiles in the Waitemata and Manukau Harbours
(1.6 MB PDF)

During the development of these ICMPs, concerns were raised within the councils that concentrations of some metals in the marine environment are elevated due to underlying volcanic rocks causing high background concentrations of these metals. Up to now, the high metal concentrations typical of volcanic rocks have not been observed in pre-urban sediments at the base of marine sediment cores. To extend the dataset of marine sediment pre-urban concentrations, the ARC invited NIWA to determine the metal concentration depth profiles in marine sediment cores from several locations in the Auckland region. These locations were typically intertidal mud flats in areas known to accumulate sediments.

TR2008/023 - Urban sources of copper, lead and zinc
(3.4 MB PDF)

This report compiles the latest local research and monitoring results to derive and understanding of the major sources of zinc, copper and lead that enter the stormwater networks and receiving environments in the Auckland urban area.

TR2008/024 - Grafton Road Stormwater Retention Tank Sediment Analysis
(510.3 KB PDF)

This report discusses the road run-off contaminant concentrations in the sediment, captured in the stormwater retention tank at Grafton Road, Auckland City. The location is the site of the largest stormwater retention tank in the country. The site was selected because it is located alongside a new motorway section and therefore the samples do not contain historic contaminants or run-off from other sources. The samples provide a good representation of contaminants contained in road runoff. The contaminants sampled include zinc, copper and total petroleum hydrocarbons (TPH).

TR2008/026 Sedimentation in the Okura-Weiti-Karepiro Bay System
(1.3 MB PDF)

This report provides background information on sedimentation in and sediment sources to the Okura-Weiti-Karepiro system.

TR2008/028 - Literature review of organic chemicals of emerging environmental concern in use in Auckland
(1.5 MB PDF)

This report provides a review of international literature about emerging contaminants contained in stormwater runoff (principally complex organic compounds), thesources, prevalence and effects.

TR2008/029 - The impact of urban stormwater in Auckland's aquatic receiving environment contaminants
(3.8 MB PDF)

This report summarises information relevant to Auckland's stormwater and effects based on published and unpublished information between 1995 and 2005. It will provide a readily accessible source of knowledge for all parties who require access to this information. A companion report covering the period 2005-2008 is currently underway.

TR2008/030 - Floating Vegetative Islands for Stormwater Treatment Removal of Copper, Zinc and Fine Particulates
(1.3 MB PDF)

Previously, a literature review on the use of floating vegetation islands to remove fine particulates and dissolved contaminants in stormwater treatment ponds was completed in 2006 (ARC TP324). The current report documents a follow up study in which a laboratory trial was undertaken to assess effectiveness of adding vegetated islands to stormwater detention ponds. The primary purpose of many existing stormwater ponds is flooding control, with stormwater quality treatment a secondary function. The ability of stormwater ponds to remove fine particulates and dissolved contaminants is limited. Floating wetlands can potentially increase removal of these contaminants. Fine sediment, zinc and copper removal were investigated, and different native plant species were trialed. Laboratory results suggest floating wetlands may be an option to retrofit or enhance stormwater treatment at ponds.

TR2008/031 - Conditions and values of Mangere Inlet, Whau Estuary and Tamaki Estuary
(5.2 MB PDF)

TR2008/045 Model Codes of Practice for Enhanced Stormwater Management and Improved Uptake of Low Impact
(882.9 KB PDF)

Previous studies by Auckland Regional Council (ARC) identified a number of limitations or barriers that restrict local authorities from implementing low impact design (LID) and other enhanced stormwater management techniques. The aim of this project was to provide tools to address some of these limitations. Ultimately it was anticipated that this would result in a Model Code of Practice on which individual local authorities can base the drafting or revision of their Codes of Practice.

TR2008/046 Weiti Sediment Monitoring 2007
(11.4 MB PDF)

This report documents sediment monitoring results undertaken in 2007 to record metal prevalence and accumulation in the Weiti river. Copper, zinc, lead, arsenic and chromium were measured.

TR 2008/049 Southeastern Manukau Harbour / Pahurehure Inlet Contaminant Study: Landuse Analysis
(1.9 MB PDF)

This report describes the preparation of landuse information for the historical period (1940 to 2000), the current time (2001), and the future period (2002 to 2100). This landuse information is required as input to the GLEAMS-SEM model which, in the Southeastern Manukau Harbour / Pahurehure Inlet Contaminant Study, is used to hindcast/predict sediment runoff from the rural areas of the catchment surrounding the Southeastern Harbour / Pahurehure Inlet.

TR 2008/050 Southeastern Manukau Harbour / Pahurehure Inlet Contaminant Study: Sediment Load Model Structure, Setup and Input Data
(2.4 MB PDF)

This report describes the implementation and data requirements of the GLEAMS model for simulating sediment generation in rural areas of the catchment of the Southeastern Manukau Harbour / Pahurehure Inlet. The model so implemented is called "GLEAMS-SEM".

TR 2008/051 Southeastern Manukau Harbour / Pahurehure Inlet Contaminant Study: Sediment Load Model Evaluation
(2.1 MB PDF)

This report describes the evaluation of the outputs of the sediment load model, GLEAMS-SEM. As part of this study we have developed a routing procedure to simulate conveyance of sediment to harbour outfalls. This report describes the evaluation of the ability of the combined models (GLEAMS and the routing function) to predict sediment loads discharged to the Harbour.

TR 2008/052 Southeastern Manukau Harbour / Pahurehure Inlet Contaminant Study: Sediment Load Model Results
(1.9 MB PDF)

This report describes model results for the ‘historical’ period (1945 to 2000, the ‘current time’ (2001), and the ‘future’ period (2002 to 2100) to hindcast/predict sediment runoff from the rural areas of the catchment surrounding the Southeastern Manukau Harbour / Pahurehure Inlet. The results presented here are provided to both the CLM model as an input for the estimation of urban contaminant loads and the USC-3 model as an input for the hindcasting and prediction of sediment and contaminant accumulation in Harbour subestuaries.

TR 2008/053 Southeastern Manukau Harbour / Pahurehure Inlet Contaminant Study: Predictions of Stormwater Contaminant Loads
(1.2 MB PDF)

This report describes the loads of TSS (total suspended solids), total zinc and total copper hindcast for the historical period (1940–2001) and predicted for the future period (2001–2100) for each of 11 consolidated harbour outfalls in the catchment of the Southeastern Manukau Harbour.

TR 2008/054 Southeastern Manukau Harbour / Pahurehure Inlet Contaminant Study: Harbour Sediments
(3.9 MB PDF)

This report presents the results of a study of sediments within the harbour, undertaken as part of the broader modelling project. The study is intended to provide information on particle sizes, and copper and zinc concentrations within the present-day surface sediments, and to measure sediment accumulation rates. Surface sediment samples from 42 sites and core samples from 6 sites were analysed for particle size, bulk density, and copper and zinc concentrations. The sediment cores were also analysed for radioisotope profiles, from which sediment accumulation rates were subsequently calculated.

TR 2008/055 Southeastern Manukau Harbour / Pahurehure Inlet Contaminant Study: Harbour Hydrodynamics and Sediment Transport Fieldwork
(740.0 KB PDF)

The primary objective of the Pahurehure fieldwork was to collect: tidal and hydrographic data for the setup and alibration of the harbour/inlet DHI hydro-dynamical model; and wave statistics and suspended sediment loads to calibrate the DHI harbour/inlet sediment-transport model. The alibrated model would then be used to produce a series of weather (rain, wind) driven simulations of catchment derived sediment transport. The final (time integrated) results from these simulations produce predicted levels of suspended sediment load, sediment attenuation and a net-bed deposition for 3 sediment size fractions. These values are then post-processed into a form ready for use in the USC model.

TR 2008/056 Southeastern Manukau Harbour / Pahurehure Inlet Contaminant Study: Hydrodynamic, Wave and Sediment Transport Model Implementation and Calibration
(3.0 MB PDF)

This report addresses the implementation and calibration of three models used in the study: an estuarine hydrodynamic model, a wave model, and a sediment-transport model. Together these simulated the dispersal of contaminants and sediments by physical processes such as tidal currents and waves.

TR 2008/057 Southeastern Manukau Harbour / Pahurehure Inlet Contaminant Study: Implementation and Calibration of the USC-3 Model
(3.4 MB PDF)

This report describes the implementation and calibration of the USC-3 model for theStudy. The model, which functions as a decision-support scheme, predicts sedimentation and accumulation of contaminants (including zinc and copper) in the bed sediments of estuaries on the “planning timescale”, which is decades and greater. Because the USC-3 model makes explicit use of estimates of future heavy-metal and sediment loads from the catchment, it is truly a predictive model compared to, say, simply extrapolating past heavy-metal concentrations in harbour bed sediments. Because future sediment and heavy-metal loads will change according to management practice and policy, model predictions can be used to compare performance of competing development scenarios and to evaluate efficacy of zinc source control of industrial areas. In addition, the model tracks the movement of sediments and contaminants, which enables links between sources (on the land) and sinks (in the estuary) to be identified. This facilitates targeting of management intervention.

TR 2008/058 Southeastern Manukau Harbour / Pahurehure Inlet Contaminant Study: Predictions of Sediment, Zinc and Copper under Future Development Scenario 1
(3.9 MB PDF)

This report describes predictions that have been made by the USC-3 (“Urban Stormwater Contaminant”) model. The model, which functions as a decision-support scheme, predicts sedimentation and accumulation of contaminants (including zinc and copper) in the bed sediments of estuaries on the “planning timescale”, which is decades and greater.

TR 2008/059 Southeastern Manukau Harbour / Pahurehure Inlet Contaminant Study: Predictions of Sediment, Zinc and Copper Accumulation under Future Development Scenarios 2, 3 and 4
(3.7 MB PDF)

This report describes predictions that have been made by the USC-3 (“Urban Stormwater Contaminant”) model. The model, which functions as a decision-support scheme, predicts sedimentation and accumulation of contaminants (including zinc and copper) in the bed sediments of estuaries on the “planning timescale”, which is decades and greater.

TR 2008/032 Central Waitemata Harbour contaminant study Land use scenarios
(2.5 MB PDF)

The aim of the Central Waitemata Harbour Contaminant Study is to model contaminant (zinc, copper) and sediment accumulation in the harbour to identify significant contaminant sources, and to test the efficacy of stormwater treatment and zinc source control of industrial roofs. The objective is to use models to predict contaminant build-up and movement in the Central Waitemata Harbour. This report describes the development of land use information for the catchment of the Central Waitemata Harbour for the historical period, 1940 to 2001, the current year 2001, and the future years, 2001 to 2100. The emphasis is on developing land use information required as input to the GLEAMS model, which is used to hindcast/predict sediment run-off from the rural parts of the catchment surrounding the Central Waitemata Harbour.

TR2008/033 - Central Waitemata Harbour contaminant study - background metal concentrations in soils
(844.2 KB PDF)

This report belongs to the Central Waitemata Harbour Contaminant Study series. It provides information on background concentrations of total recoverable concentrations of zinc and copper in soil samples from volcanic fields in Auckland City. The introduction of volcanic soils into receiving environments represents a “natural” or “background” input of trace metals compared to anthropogenic sources. In predicting accumulation of metals in receiving environments it is necessary to account for both natural and anthropogenic sources.

TR2008/034 - Central Waitemata Harbour contaminant study - harbour sediments
(3.3 MB PDF)

This report belongs to the Central Waitemata Harbour Contaminant Study series.It describes particle size and fall speed of suspended sediments discharged to the CWH from the Whau River and Henderson Creek. Physical characteristics of the surface sediments of the CWH, Sediment accumulation rates and mixing of sediment deposits by physical and biological processes are also described.

TR 2008/035 Central Waitemata Harbour contaminant study. Trace metal concentrations in harbour sediments
(1.8 MB PDF)

This report presents results from a summer 2006 field survey and describes the physical and chemical characteristics of Central Waitemata Harbour sediments, in particular, concentrations of the trace metals copper and zinc. Results cover 33 surface sediment samples, as well as three downcore sediment profiles. Metal concentrations were determined for three size fractions: <25 m (clay), 25–63 m (silt), and 63–250 m (sand). Information developed here was used to calibrate and validate the Urban Stormwater Contaminant model, which was used to predict sedimentation and heavy metal accumulation in bed sediments of the harbour.

TR2008/036 - Central Waitemata Harbour contaminant study - hydrodynamics and sediment transport fieldwork
(2.9 MB PDF)

This report belongs to the Central Waitemata Harbour Contaminant Study series. This report documents the fieldwork conducted in 2006 to acquire data needed to calibrate the model that will be used to simulate the dispersal of contaminants and sediments in the harbour by physical processes such as tidal currents and waves.

TR 2008/037 Central Waitemata Harbour contaminant study. Harbour hydrodynamic, wave and sediment transport model implementation and calibration
(15.8 MB PDF)

This report describes the implementation and calibration of three models used in the Central Waitemata Harbour study: an estuarine hydrodynamic model, a wave model, and a sediment-transport model. Together, these simulate the dispersal of contaminants and sediments by physical processes such as tidal currents and waves. The particular models used in the study are the DHI Water and Environment (DHI) MIKE3 FM hydrodynamic model, the DHI MIKE3 MT sediment transport model, and the SWAN wave model.

TR 2008/040 Central Waitemata Harbour contaminant study. GLEAMS model structure, set-up and input data requirements
(1.2 MB PDF)

This report describes the implementation of the Groundwater Loading Effects of Agricultural Management Systems, GLEAMS model for simulating sediment generation in the rural parts of the catchment of the Central Waitemata Harbour. The model so implemented is called “GLEAMS-CWH”. The GLEAMS-CWH model is used to hindcast sediment run-off for the historical period, 1940 to 2001 and to predict sediment run-off for the future period, 2001 to 2100. The hindcast data are used to calibrate the USC-3 model. The predictions are used in the evaluation of future catchment development scenarios. GLEAMS-CWH is a field-scale physics-based mathematical model for predicting daily run-off of water and sediment. The primary information required by the model is the catchment characteristics, including climate, topography, soils and land use. A GIS interface is used to manage the spatial information required as input (eg, soil patterns, land use and topography).

TR2008/041 - Central Waitemata Harbour Contaminant Study - Model Results for Rural and Earthworks Sediment Loads from the Catchment
(2.1 MB PDF)

This report belongs to the Central Waitemata Harbour Contaminant Study series. The GLEAMS sediment-generation model, predicts sediment erosion from the land and transport down the stream channel network. Predictions of sediment supply are necessary because, ultimately, sediment eroded from the land dilutes the concentration of contaminants in the bed sediments of the harbour, making them less harmful to biota. The GLEAMS model provides data which feeds into the USC-3 model.

TR 2008/042 Central Waitemata Harbour contaminant study. USC-3 model description, implementation and calibration
(9.0 MB PDF)

This report describes the USC-3 (“Urban Stormwater Contaminant”) model, which has been developed specifically for the Central Waitemata Harbour study. The model, which functions as a decision-support scheme, predicts sedimentation and accumulation of contaminants (including zinc and copper) in the bed sediments of estuaries on the “planning timescale”, which is decades and greater.

TR 2008/043 Central Waitemata Harbour contaminant study. Predictions of sediment, zinc and copper accumulation under future development scenario 1
(3.6 MB PDF)

This report describes predictions from the USC-3 (“Urban Stormwater Contaminant”) model, which has been developed specifically for the study. The model, which functions as a decision-support scheme, predicts sedimentation and accumulation of contaminants (including zinc and copper) in the bed sediments of estuaries on the “planning timescale”, which is decades and greater. Predictions are made for a number of development scenarios, where scenarios differ by zinc source control applied industrial roofs in urban areas, and stormwater treatment applied in urban areas. Each scenario covers 100 years into the future from the present day, which is defined as 2001. The predictions reported here are for Scenario 1, for which there is no zinc source control of industrial roofs and no additional stormwater treatment.

TR 2008/044 Central Waitemata Harbour contaminant study. Predictions of sediment, zinc and copper accumulation under future development scenarios 2, 3 and 4
(2.2 MB PDF)

This report describes predictions from the USC-3 (“Urban Stormwater Contaminant”) model, which has been developed specifically for the study. The model, which functions as a decision-support scheme, predicts sedimentation and accumulation of contaminants (including zinc and copper) in the bed sediments of estuaries on the “planning timescale”, which is decades and greater. Predictions are to be made for a number of development scenarios, where scenarios differ from each other only by anthropogenic metal (as opposed to the “natural” metals that are present in the soils of the catchment) run-off, and urban (as opposed to rural) sediment run-off. Each scenario covers 100 years into the future from the present day, which is defined as 2001.