1L1: 2 .ø4!) ESD LIBRARY DEPARTMENT OF ENVIRONMENTAL WESTRALIA SQUARE 141 ST. GEORGES TERRACE NORTHAM BYPASS CONSULTATIVE ENVIRONVW DEPARTMENT OF ENVIRONMENT 141 ST GEORGE'S TERRACE PERTH, PREPARED FOR: Main Roads Western Australia PREPARED BY: BSD Consuftants Pty Ltd 1 Seat Road, Appkcross Western Australia 6153 Ph 3162988 Fax 364.2840 Date: August 1993 INVITATION The Environmental Protection Authority. (EPA) invites people to make a submission on this proposal. The Consultative Environmental Review (CER) proposes the bypassing. of the Northam townsite by the Great Eastern Highway. In accordance with the Environmental Protection Act, a CER has been prepared which describes this proposal and its likely effects on the environment. The CER is available for a public review period of 4 weeks from August 9, 1993, closing on September 3, 1993. Following receipt of comments from government agencies and the public, the EPA will prepare an assessment report with recommendations to the government, taking into account issues raised in public submissions. Why write a submission? A submission is a way to provide information, express your opinion and put forward your suggested course of action - including any alternative approach. It is useful if you indicate any suggestions you have to improve the proposal. All submissions received by the EPA will be acknowledged. Submissions may be fully or partially utilised in compiling a summary of the issues raised, or where complex or technical issues are raised, a confidential copy of the submission (or part thereof) may be sent to the proponent. The summary of issues raised is normally inc luded in the EPA's assessment report. Submitters would not be identified to the proponent without the submitters permission. Why not join a group? If you prefer not to write you own comments, it may be worthwhile joining with a group or other groups interested in making a submission on similar issues. Joint submissions may help to reduce the workload for an individual or group as well as increase the pool of ideas and information. If you form a small group (up to 10 people) please indicate all the names of the participants. If your group is larger, please indicate how many people your submission represents. Developing a submission You may agree or disagree with, or comment on, the general issues discussed in the CER or the specific proposals. It helps if you give reasons for your conclusions, supported by relevant data. You may make an important contribution by suggesting ways to make the proposal environmentally more acceptable. When making comments on specific proposals in the CER: Clearly state your point of view; Indicate the source of your information or argument if this is applicable; 0 Suggest recommendations, safeguards or alternatives. Points to keep in mind By keeping the following points in mind, you will make it easier for your submission to be analysed: attempt to list points so that issues raised are clear. A summary of your submissions is helpful; refer each point to the appropriate section, chapter or recommendation in the CER; if you discuss different sections of the CER, keep them distinct and separate, so there is no confusion as to which section you are considering; attach any factual information you may wish to provide and give details of the source. Make sure your information is accurate. Remember to include: your name 0 address date. The closing date for submission is September 3, 1993. Submissions should be addressed to: The Environmental Protection Authority 'Westralia Square' 141 St Georges Terrace Perth 6000 Attention: Nicholas Wimbush TABLE OF CONTENTS ..•page. 1.0: INTRODUCTION ............ ............................ 1 1.1 Purpose of the Document ..............................1 1.2 Background .......................................1 1.3 Scope of Assessment .................................3 1.4 The Proponent .....................................3 2.0 NEED FOR THE PROPOSAL ................................ 5 2.1 Problems .With Existing Alignment .......................... 5 2.1.1 Traffic ...................................... 5 2.1.2 Environmental .....................................7 2.1.3 Community Imposition ..............................8 2.2 Community Needs.. r. .................................. 8 3.0 EVALUATION OF ALTERNATIVES ................................10 3.1 Route 6 ...........................................10 3.2 Route 6A .......................................11 3.3 Route9 ........................................12 3.4 The "Do Nothing" Approach ...........................12 3.4.1 Traffic .....................................13 3.4.2 Environmental ...............................14 3.4.3 Social .........................................14 3.5 The Preferred Bypass Alignment ........................14 4.0 DESCRIPTION OF THE PROPOSAL............................... 17 4.1 Approach/Design Philosophy .............................17 4.1.1 General ......................................17 4.1.2 Cross Section ...............................17 4.1.3 Longitudinal Profile.............................18 4.1.4 Pavement ...................................18 4.1.5 Intersections ....................................18 4.2 Project Scope ........................................18 4.2.1 Roadworks .... 18 4.2.2 Bridges .......................... 19 4.2.3 Stormwater Drainage ..............................20 4.2.4 Roadside Stopping Places ..........................20 4.3 Traffic and Access Movements ..........................20 4.3.1 Functional Road Hierarchy ........................21 4.3.2 Traffic Volumes and Accidents ....................21 4.3.3 Heavy Goods Vehicles. (HGV's) ........................22 4.3;4 Transport of Dangerous Goods ........................22 4.3.5 Local and Regional Access ........................23 4.3.6 Summary ....................................24 5 0 DESCRIPTION OF THE ENVIRONMENT 25 5.1 Introduction ..................................... 25 5.2 Available Information and Studies Conducted ................ 25 5.3 Physical Environment ............................... 28 5.3.1 Climate .................................... 28 5.3.2 Landforms and Soils .............................. 30 5.3.3 Hydrology ................................... 31 5.3.4 Floodplain Characteristics ......................... 32 5.3.5 Water Quality ............................... 33 5.4 Biological Environment ............................... 34 5.4.1 Vegetation ................................. 34 5.4.1.1 Vegetation along Route 6 Alignment (Figures 1A and 1B) .................. 35 5.4.1.2 Vegetation along Route 6A Alignment (Figures 2A and 2B) .................. 37 5.4.1.3 Vegetation along Route 9 Alignment (Figures 3A and 3B) .................. 38 5.4.2 Fauna and Habitat .............................. 40 5.5 Human Environment ............................... 41 5.5.1 Economic Base ............................... 41 5.5.2 Community Attitudes ........................... 42 5.5.3 Cultural Significance ........................... 43 5.5.4 Landscape and Amenity Values ..................... 45 5.5.5 Recreational Opportunities ....................... 46 6.0 ENVIRONMENTAL IMPACT ASSESSMENT ...................47 6.1 Introduction and Objectives ...........................47 6.2 Potential Environmental Impacts of Route 6 ............... 47 6.2.1 Preconstruction Impacts .........................47 6.2.1.1 Scope and Objectives ...................47 6.2.1.2 Physical Environment .................48 6.2.1.3 Biological Environment ................48 6.2.1.4 Human Environment ...................48 6.2.2 During Construction Impacts ......................50 6.2.2.1 Scope and Objectives ..................50 6.2.2.2. Physical Environment .................50 6.2.2.3 Biological Environment ................52 6.2.2.4 Human Environment .................. 55 6.2.3 Post-Construction Impacts ........................ 59 6.2.3.1 Scope and Objectives .................. 59 6.2.3.2 Physical Environment ..................60 6.2.3.3 Biological Environment ..................62 6.2.3.4 Human Environment ...................63 6.3 Potential Environmental Impacts of Route 6A ................68 6.3.1 Preconstruction Impacts .........................68 6.3.1.1 Scope and Objectives ..................68 6.3.1.2 Physical Environment ..................68 6.3.1.3 Biological Environment ................69 6.3.1.4 Human Environment 69 6.3.2 During Construction Impacts ........................ 71 6.3.2.1 Scope and Objectives ................... 71 6.3.2.2. Physical Environment... ................. 71 6.3.2.3 Biological Environment ................ 73 6.3.2.4 Human Environment .................. 76 6.3.3 Post-Construction Impacts .......................... 80 6.3.3.1 Scope and Objectives .................... 80 6.3.3.2 Physical Environment ................. 80 6.3.3.3 Biological Environment ................ 82 6.3.3.4 Human Environment ........... .......... 84 6.4 Potential Environmental Impacts of Route 9 .................. 89 .6.4.1 Pre-Construction Impacts . .. .. .................... 89 6.4.1.1 Scope and Objectives .................. 89 6.4.1.2 Physical Environment .................. 89 6.4.1.3 Biological Environment ................ 89 6.4.1.4 Human Environment .................. 89 6.4,2 During Construction -Impacts ........................ 91 6.4.2.1 Scope and Objectives ................... 91 6.4.2.2 Physical Environment ................. 91 6.4.2.3 . Biological Environment ................ 93 6.4.2.4 Human Environment .................