Staff Report
Transcription
Staff Report
Staff Report To: From: Subject: Date: RVCA Board of Directors Don Maciver, MCIP RPP Director of Planning Adoption of a regulation to manage development, interference with wetlands and alterations to shorelines and watercourses November 16, 2005 Recommendation: That the staff report be received for information, and whereas a local regulation to manage “development, interference with wetlands and alterations to shorelines and watercourses” has been prepared in conformity with the provisions outlined in Section 28 of the Conservation Authorities Act, and standards for mapping and public consultation have been followed; therefore, the Rideau Valley Conservation Authority adopts the subject regulation; and further, that the said regulation and related documentation be submitted to the Conservation Ontario Peer Review Committee and subsequently to the Ministry of Natural Resources for approval by the Minister. A Work Plan for preparation of a package conforming to established standards and procedures and for adoption of a Generic Regulation was approved by the Board of Directors at their August 2004 meeting. It was recognized that implementation would be staged and that the initial phase of project would focus on ensuring that existing hazard schedules were maintained and newer hazard mapping, where available, added into the regulatory program. The Work Plan was subsequently amended, based on a resolution approved at the September 2005 Board meeting, to provide for the inclusion of provincially significant wetlands appearing on approved local Official Plan schedules in our first round submission. This amended approach was based on input provided by the Provincial Technical Committee formed to assist CA’s with the preparation of submissions to the Province. Information appended following the regulation text forms part of our submission to the Peer Review Committee and is intended to affirm that the established standards for mapping and for public consultation have been followed. Most of the required work has been undertaken in house by staff of the Planning program, the Watershed Science and Engineering section, and Communications staff. CONFIDENTIAL Until filed with the Registrar of Regulations ONTARIO REGULATION made under the CONSERVATION AUTHORITIES ACT RIDEAU VALLEY CONSERVATION AUTHORITY: REGULATION OF DEVELOPMENT, INTERFERENCE WITH WETLANDS AND ALTERATIONS TO SHORELINES AND WATERCOURSES Definition 1. In this Regulation, “Authority” means the Rideau Valley Conservation Authority. Development prohibited 2. (1) Subject to section 3, no person shall undertake development, or permit another person to undertake development in or on the areas within the jurisdiction of the Authority that are, (a) adjacent or close to the shoreline of inland lakes that may be affected by flooding, erosion or dynamic beaches, including the area from the furthest offshore extent of the Authority’s boundary to the furthest landward extent of the aggregate of the following distances: (i) the 100 Year flood level; (ii) the predicted long term stable slope projected from the existing stable toe of the slope or from the predicted location of the toe of the slope as that location may have shifted as a result of shoreline erosion over a 100-year period; and (iii) 15 metres inland. (b) river or stream valleys that have depressional features associated with a river or stream, whether or not they contain a watercourse, the limits of which are determined in accordance with the following rules: 3 (i) where the river or stream valley is apparent and has stable slopes, the valley extends from the stable top of bank, plus 15 metres, to a similar point on the opposite side, (ii) where the river or stream valley is apparent and has unstable slopes, the valley extends from the predicted long term stable slope projected from the existing stable slope or, if the toe of the slope is unstable, from the predicted location of the toe of the slope as a result of stream erosion over a projected 100-year period, plus 15 metres, to a similar point on the opposite side, (iii) where the river or stream valley is not apparent, the valley extends the greater of, (A.) the distance from a point outside the edge of the maximum extent of the flood plain under the applicable flood event standard, plus 15 metres, to a similar point on the opposite side, and (B.) the distance from the predicted meander belt of a watercourse, expanded as required to convey the flood flows under the applicable flood event standard, plus 15 metres, to a similar point on the opposite side; (c) hazardous lands; (d) wetlands; or (e) other areas where development could interfere with the hydrologic function of a wetland, including areas within 120 metres of all provincially significant wetlands and wetlands greater than 2 hectares in size, and areas within 30 metres of wetlands less than 2 hectares in size, but not including those where development has been approved pursuant to an application made under the Planning Act or other public planning or regulatory process. (2) The areas described in subsection (1) are the areas referred to in section 12 except that, in case of a conflict, the description of the areas provided in subsection (1) prevails over the descriptions referred to in that section. 4 Permission to develop 3. (1) The Authority may grant permission for development in or on the areas described in subsection 2 (1) if, in its opinion, the control of flooding, erosion, dynamic beaches, pollution or the conservation of land will not be affected by the development. (2) The permission of the Authority shall be given in writing, with or without conditions. Application for permission 4. A signed application for permission to undertake development shall be filed with the Authority and shall contain the following information: 1. Four copies of a plan of the area showing the type and location of the development. 2. The proposed use of the buildings and structures following completion of the development. 3. The start and completion dates of the development. 4. The elevations of existing buildings, if any, and grades and the proposed elevations of buildings and grades after development. 5. Drainage details before and after development. 6. A complete description of the type of fill proposed to be placed or dumped. Alterations prohibited 5. Subject to section 6, no person shall straighten, change, divert or interfere in any way with the existing channel of a river, creek, stream or watercourse or change or interfere in any way with a wetland. Permission to alter 6. (1) The Authority may grant a person permission to straighten, change, divert or interfere with the existing channel of a river, creek, stream or watercourse or to change or interfere with a wetland. (2) The permission of the Authority shall be given in writing, with or without conditions. 5 Application for permission 7. A signed application for permission to straighten, change, divert or interfere with the existing channel of a river, creek, stream or watercourse or change or interfere with a wetland shall be filed with the Authority and shall contain the following information: 1. Four copies of a plan of the area showing plan view and cross-section details of the proposed alteration. 2. A description of the methods to be used in carrying out the alteration. 3. The start and completion dates of the alteration. 4. A statement of the purpose of the alteration. Cancellation of permission 8. (1) The Authority may cancel a permission if it is of the opinion that the conditions of the permission have not been met. (2) Before cancelling a permission, the Authority shall give a notice of intent to cancel to the holder of the permission indicating that the permission will be cancelled unless the holder shows cause at a hearing why the permission should not be cancelled. (3) Following the giving of the notice, the Authority shall give the holder at least five days notice of the date of the hearing. Validity of permissions and extensions 9. (1) A permission of the Authority is valid for a maximum period of 24 months after it is issued, unless it is specified to expire at an earlier date. (2) A permission shall not be extended. Appointment of officers 10. The Authority may appoint officers to enforce this Regulation. Flood event standards 11. (1) The applicable flood event standards used to determine the maximum susceptibility to flooding of lands or areas within the watersheds in the area of jurisdiction of the Authority is the 100 Year Flood Event Standard described in the Schedule. 6 Areas included in the Regulation Limit 12. Hazardous lands, wetlands, shorelines and areas susceptible to flooding, and associated allowances, within the watersheds in the area of jurisdiction of the Authority are delineated by the Regulation Limit shown on maps 1 to 256 dated November 2005 and filed at the head office of the Authority at 1128 Mill Street (Manotick) in the City of Ottawa under the map title “Ontario Regulation 97/04: Regulation for Development, Interference with Wetlands and Alterations to Shorelines and Watercourses”. SCHEDULE 1. The 100 Year Flood Event Standard means rainfall or snowmelt, or a combination of rainfall and snowmelt producing at any location in a river, creek, stream or watercourse, a peak flow that has a probability of occurrence of one per cent during any given year. 7 Made by: RIDEAU VALLEY CONSERVATION AUTHORITY: ……………………………………………….. Signature ……………………………………………….. Please Print Name and Title ……………………………………………….. Signature ……………………………………………….. Please Print Name and Title Date made: ……………………………… I certify that I have approved this Regulation. …………………………………………… Minister of Natural Resources Date approved: ………………………….. 8 8 9 Regulation Limit Mapping Index 10 10 11 Rideau Valley Conservation Authority Detailed Consultation Record Generic Regulation Peer Review Committee Contents Mailing list of contacts .........................................................................16 Sign-in sheets from public meeting .....................................................19 Notice of public meeting ......................................................................23 Sample letter of notice to municipality and contacts............................24 Sample brochure.................................................................................25 Outline of Public Meeting Format ........................................................27 List and outline of context of all submissions ......................................28 received and response provided by RVCA Sample Display Panels .......................................................................31 Website ...............................................................................................33 12 Mailing List of Contacts Murray Hackett Clerk/Administrator Township of Montague 6547 Roger Stevens Drive P.O. Box 755 Smiths Falls, ON K7A 4W6 Darlene Noonan CAO/Clerk - Treasurer Township of Athens P.O. Box 189, 1 Main Street West Athens, ON K0E 1B0 Mrs. Sharon Wilkinson, CAO Clerk Township of Augusta 3560 Co. Rd. 26, R. R. 2 Prescott, ON K0E 1T0 Howard Smith Administrator Township of North Dundas 636 St. Lawrence Street P.O. Box 489 Winchester, ON K0C 2K0 Cynthia Moyle CAO Township of Beckwith P.O. Box 989 1702 9th Line Beckwith Carleton Place, ON K7C 3P2 Cahl Pominville Interim Chief Administrative Officer Corporation of the Municipality of North Grenville P.O. Box 130 515 Prescott Street Kemptville, ON K0G 1J0 Heather Fox Clerk Administrator Township of Central Frontenac 1084 Elizabeth Street, P.O. Box 89 Sharbot Lake, ON K0H 2P0 Kelly Pender Chief Administrative Officer Town of Perth Town Hall, 80 Gore Street East Perth, ON K7H 1H9 Mr. Yves Rousselle Manager, Environmental Services City of Clarence-Rockland 1560 Laurier Avenue Rockland, ON K4K 1P7 Robert Maddocks Chief Administrative Officer Township of Rideau Lakes 1439 County Road 8 at Chantry P.O. Box 500 Delta, ON K0E 1G0 Mr. Paul Snider Clerk-Treasurer Township of Drummond/North Elmsley 310 Port Elmsley Road, R.R.#5 Perth, ON K7H 3C7 Wayne Brown Director of Corporate Services Town of Smiths Falls Box 695, Town Hall, 77 Beckwith Street North Smiths Falls, ON K7A 4T6 Ms. Yvonne Robert Clerk & Council Administrator Township of Elizabethtown-Kitley R.R. 2, 6544 New Dublin Road Addison, ON K0E 1A0 Gordon Burns Clerk/Administrator Township of South Frontenac Box 100, 4432 George Street Sydenham, ON K0H 2T0 Don Reid Chief Administrative Officer Village of Merrickville-Wolford P.O. Box 340, 317 Brock Street West Merrickville, ON K0G 1N0 Kathy Coulthart-Dewey Chief Administrative Officer/Clerk Tay Valley Township 217 Harper Road, R.R.4 Perth, ON K7H 3C6 12 13 Scott Bryce Clerk-Treasurer Village of Westport P.O. Box 68, 30 Bedford Street Westport, ON K0G 1X0 Secrétaire Conseil des écoles catholiques du Centre-Est de l'Ontario 4000 Labelle rue Gloucester, Ontario K1J 1A1 Mr. Greg Geddes City of Ottawa Corporate Services Officer 110 Laurier Avenue West Ottawa, ON K1P 1J1 Embridge Gas Distribution 400 Coventry Road Ottawa, Ontario K1K 2C7 Union Gas Limited 520 Gardiners Road Kingston, Ontario K7L 4Y6 Doreen Davis Sharbot Lake Mishigama Anishnabae Algonquin First Nation 3102, RR#2 Sharbot Lake, Ont. K0H 2P0 Randy Malcolm The Ardoch Algonquin First Nation RR#3 Eganville, Ont. K0J 1T0 Secretary Ottawa-Carleton District School Board 133 Greenbank Road Nepean, Ontario K2H 6L3 Secretary Upper Canada District School Board 225 Central Avenue Brockville, Ontario K6V 5X1 Secretary Ottawa Carleton Catholic School Board 570 West Hunt Club Nepean, Ontario K2G 3R4 Secretary Catholic District School Board of Eastern Ontario Box 2222, 2755 Highway 43 Kemptville, Ontario K0G 1J0 Secrétaire Conseil des écoles publiques de l'Est de l'Ontario 2445 boulevard St-Laurent Ottawa, Ontario K1G 6C3 Rideau St. Lawrence Distribution Inc. 985 Industrial Street Box 699 Prescott, Ontario K0E 1T0 Almonte Hydro 28 Mill Street Almonte, Ontario K1A 1A0 Direct Energy Business Services 409, 29 Hwy Smiths Falls, Ontario K7A 4S5 Perth Public Utilities Commission 15 Sunset Boulevard Perth, Ontario K7H 2Y3 Public Utilities Commission 25 Front Avenue West Brockville, Ontario K6V 4J2 Westport Hydro 30 Bedford Street Westport On K0G 1X0 Brian McCormick Manager, Environmental Services & Approvals Hydro One Networks 483 Bay Street, 13th Floor, North Tower Toronto, Ontario M5G 2P5 Enza Cancilla Manager, Public Affairs, Corporate Communications Hydro One Networks 483 Bay Street, 8th Floor, South Tower Toronto, Ontario M5G 2P5 14 Barrie Askew Ontario Power Generation 8 Trent Drive PO Box 966 Cambleford, Ontario K0L 1L0 Mr. Grant Richie District Manager Ministry of Natural Resources Kemptville District P. O. Box 2002 Kemptville, ON K0G 1J0 Adèle Malo Vice President, Law & General Counsel/ Sustainable Development Ontario Power Generation 700 University Avenue Toronto, Ontario M5G 1X6 Superintendent Rideau Canal National Historic Site Parks Canada Agency 34A Beckwith Street South Smiths Falls, ON K7A 2A8 TransCanada Pipelines 55 Yonge Street Toronto, ON M5E 1J Margo Lienhard Manager, Community Planning and Development Eastern Municipal Services Office Municipal Affairs and Housing 8 Estate Lane, Rockwood House Kingston, ON K7M 9A8 Enbridge Pipelines Inc. 10201 Jasper Avenue P.O. Box 398 Edmonton, AB T5J 2J9 Provincial Planning and Environmental Services Branch Municipal Affairs and Housing 777 Bay St, 14th Floor Toronto ON M5G 2E5 Great Lakes Gas Transmission Company 5250 Corporate Drive Troy, MI 48098 (248) 205-7400 Fisheries & Oceans Canada Communications Branch 200 Kent Street 13th Floor, Station 13228 Ottawa, Ontario K1A 0E6 Trans-Northern Pipelines Inc. 310-45 Vogell Road Richmond Hill, Ontario L4B 3P6 Kent Kirkpatrick City Manager City of Ottawa 110 Laurier Avenue West Ottawa, ON K1P 1J1 14 15 Sign-in Sheets 16 16 17 18 18 Notice of Public Meeting Perth Courier Manotick Messenger The Packet Barrhaven Independent Nepean This Week Kanata Kourier The Review Stittsville News Kemptville Advance Carleton Place Canadian Almonte Gazette Arnprior Chronicle Guide Orleans Star Brockville Recorder & Times EMC Record News — Full coverage New Lanark Era The Frontenac News Carp Valley Press Kingston This Week Hunt Club/Riverside News Land of Lakes Sun Tweed News 20 Sample Letter Dear Sir/Madame: The Rideau Valley Conservation Authority (RVCA) is in the process of adopting amendments to the “Fill, Construction and Alteration to Waterway” Regulation (Ontario Regulation 166 under Section 28 of the Conservation Authorities Act), which has been in place since the late 1970s. The current legislation will be replaced by a “Development, Interference with Wetlands and Alterations to Shorelines and Watercourse” Regulation (adopted as Ontario Regulation 97/04). This regulation, also known as the “Generic Regulation,” will provide one consistent format for a regulation to be administered by all Conservation Authorities in Ontario. The changes to the legislation are due to the Red Tape Reduction Commission initiative to bring clarity and consistency to existing legislation and eliminate no longer needed legislation while still safeguarding public health, safety and the environment. The regulation will complement the Planning Act and Provincial Policy Statements, as well as be reflective of the provisions of municipal official plans and by-laws. All Conservation Authorities will implement the regulation by May 1, 2006. The regulation will assist the Conservation Authority to meet two of its major priorities, namely safeguard water resources and protect people against natural hazards. The Rideau Valley Conservation Authority (RVCA) with Mississippi Valley Conservation (MVC) will host a series of public information meetings to present the new regulation and revised mapping. You may have seen notices in local papers to this effect. The meetings are scheduled as follows: • October 18, 5–9 pm — MVC/RVCA: Hall D, Nepean Sportsplex, 1701 Woodroffe Avenue at West Hunt Club, Ottawa • October 19, 3–9 pm — MVC/RVCA: Perth & District Community Centre (Arena), 2 Beckwith Street East, Perth • October 25, 3–9 pm — RVCA: Suite 2, North Grenville Municipal Centre, 285 County Road 44, Kemptville • October 27, 3–9 pm — MVC: West Carleton Client Services Centre, Kinburn, 5670 Carp Road, Kinburn We will also be contacting municipal staff to discuss with them the details of this amendment. If you have any questions, please call me at (613) 692-3571 ext. 1105, 1-800-267-3504 ext. 1105, or email me at [email protected] or visit our website at www.rideauvalley.on.ca. Regards, Don Maciver MCIP, RPP Director, Planning and Regulations Encl. 20 21 22 22 23 Public Meeting Format Approximately 10 staff were available for one-on-one public dialogue; this met or exceeded the need at most times during the sessions. Maps, in both digital and hardcopy format, were available for public viewing. Public Information sessions were held at well known public venues at three communities within the watershed. The public information sessions were held from 3:00 to 9:00 p.m (six hours) each (5- 9 in the City of Ottawa). Twenty-one 32-inch by 24-inch display panels were prepared for public viewing. The panels explain the Generic Regulation in a visual, easy-tounderstand format. As well, there were panels that highlighted natural hazards. A DVD presentation (TRCA) of the events surrounding Hurricane Hazel and Conservation Authorities was played in a continuous loop on a large screen throughout the evening. Information was available for the public to take, including: Ontario Regulation 97/04 S. 28 of the Conservation Authorities Act RVCA’s Generic Regulation Fact Sheet, Conservation Ontario’s Generic Regulation brochure, etc. Refreshments were provided. 24 24 25 26 26 27 Sample Display Panels 28 28 29 RVCA Website 30 30 Rideau Valley Conservation Authority Methods for Delineation of Regulation Limits in Accordance with Ontario Regulation 97/04 November 16, 2005 Background and Purpose The Rideau Valley Conservation Authority intends to seek approval from the Ontario Minister of Natural Resources for a new regulation under Section 28 of the Conservation Authorities Act to replace regulations that have been administered by the Authority since 1976 (most recently amended in 1980). In the RVCA’s area of jurisdiction, a new regulation is required for the following reasons: ▪In the existing regulation, flood susceptible areas were delineated and “fill lines” were established along some watercourses based on technical studies which have since been superceded by more recent technical studies; the regulation limits need adjustment based on the updated technical information. ▪Technical information on flood risks is now available to support the delineation of flood susceptible areas and other hazardous lands along watercourses systems that are not presently covered by the existing fill and construction regulation ▪All of Ontario’s Conservation Authorities have until April 2006 to ensure that their regulations under Section 28 of the Act conform with the requirements of Ontario Regulation 97/04, the regulation which governs the “Content of Conservation Authority regulations under Section 28(1) of the Act: Development, Interference with Wetlands and Alterations to Shorelines and Watercourses”. In preparing its proposed regulation and associated mapping describing areas that will be subject to the regulation, RVCA has generally followed guidance provided in an August 2003 document entitled “Guidelines for Developing Schedules of Regulated Areas”, which was prepared by the Conservation Ontario Generic Regulation Technical Standards Committee, in cooperation with the Ministry of Natural Resources. In a few respects, RVCA’s methodology for delineating regulation limits has differed from the methods suggested in the Guidelines, in order to account for local watershed conditions while satisfying the intent of the Guidelines and accomplishing the objectives of the regulation framework. The purpose of this brief is to describe the methodologies that have been used by the RVCA in delineating areas that will be subject to the restrictions and requirements of its proposed regulation, with particular attention paid to methods that differ from the Guidelines’ suggested approach. The RVCA’s methodologies are subject to review and approval by: ▪the RVCA Board of Directors, as it considers a resolution to seek the Minister’s approval of the regulation, ▪the MNR/Conservation Ontario “peer review” process that has been established to assist the Ministry in it’s evaluation of CA regulation proposals, and ▪the Ministry of Natural Resources. 32 Apparent and Non-Apparent Stream Valleys The initial step in the delineation of regulation limits has been to classify streams to be placed under regulation on the basis of whether or not an “apparent stream valley” is associated with the watercourse. This has been done on a reach by reach basis. Identifiable landmarks, such as bridges and watercourse outlets, have been used to designate reaches as being predominantly of the “apparent” or the “non-apparent” type. This classification was carried out through interpretation of: topographic mapping, where it is available in sufficient detail (one metre contour interval, or better) and scale (1:5,000 or better), including o base mapping prepared in conjunction with RVCA flood plain mapping studies, o municipal base mapping (for portions of the City of Ottawa) aerial photography, in locations where topographic mapping of suitable detail and scale is not available Following the Guidelines for Developing Schedules for Regulated Areas, a stream reach has been classified as having an “apparent valley” if the valley walls are at least 3 metres in height and they have an inclination of 5:1 (horizontal : vertical), or steeper. Table 1 lists the apparent/non-apparent valley status for the stream reaches for which regulation limits have been delineated. Within the reaches that are classified as non-apparent, there are isolated locations, on one or both sides of the system, where the terrain rises higher than 3 metres from the bank of the watercourse and more steeply than at a 5:1 inclination. As an example, Steven Creek from Kars to North Gower is predominantly a system with no apparent stream valley. The watercourse flows over a flat, clay plain (formerly the bed of the post-glacial Champlain Sea) but in some locations the watercourse is close to, and might be undercutting, adjacent slopes - the exposed portions of drumlin or esker formations over which the clay deposits were laid down. Although these slopes are not part of a recognizable “river or stream valley”, local erosion and slope stability hazards could be present depending on the degree to which undercutting is occurring. The regulation limits in these isolated locations have been delineated after taking into account the perceived potential for local slope movements, using the criteria for apparent stream valleys (toe erosion allowance, stable slope allowance and erosion access allowance). In some locations, locally higher/steeper terrain adjacent to the stream (within predominantly non-apparent systems or predominantly apparent systems) is associated with bedrock formations (escarpments or outcroppings). In these situations, where it is confirmed that the local feature is associated with bedrock formations, the existing face of the slope has been considered to be inherently stable and the regulation limits have been delineated 15 metres upland from the inferred “crest of slope”. 32 33 Table 1 – Classification of Watercourse Reaches based on Presence/Absence of An Apparent Stream Valley Watercourse Reach Rideau River Hwy 417 to Ottawa River Main St to Hwy 417 O-Train Bridge to Main St Hogs Back to O-Train Bridge Black Rapids to Hogs Back Watson's Mill Dam to Black Rapids Manotick to Kars Kars to Burritts Rapids Burritts Rapids to Smiths Falls Predominant Stream Valley Apparent/Non-Apparent Non-Apparent with exceptions Non-Apparent Non-Apparent Apparent Apparent Apparent Non-Apparent Non-Apparent with exceptions Non-Apparent with exceptions Jock River Rideau River to Jockvale Road Jockvale Road to Munster Road Munster Road to Jock Trail Jock Trail to Bleeks Road Bleeks Road to Dwyer Hill Road Dwyer Hill Road to Study Limit at Ashton Apparent Non-Apparent Apparent Non-Apparent Apparent Non-Apparent Stevens Creek Rideau River to Malakoff Road Non-Apparent Kemptville Creek Rideau River to Kemptville Kemptville to Oxford Mills Non-Apparent Non-Apparent Tay River Beveridges Dam to Glen Tay Non-Apparent with exceptions Ottawa River RVCA Boundary at Shirley's Bay to Chaudiere Bridge Chaudiere Bridge to Portage Bridge Portage Bridge to Rideau River Rideau River to RVCA Boundary downstream from Cumberland Non-Apparent Non-Apparent Apparent Apparent 34 Non-Apparent Stream Valleys In reaches where there is no apparent stream valley, the regulation limit has been based on the 1:100 year flood hazard limit plus the nominal 15 metre allowance. 100 Year Flood Line For all stream reaches for which regulation limits have been delineated, 1:100 year flood lines have been determined through engineering studies, using methodologies that were consistent with applicable technical standards of practice at the time the mapping was prepared. These engineering studies are listed in Table 2. The referenced studies and associated flood plain mapping are considered by the RVCA to represent the best available analyses and estimates of the areas that are expected to be inundated under regulatory (1:100 year) flood conditions and are suitable for use in the regulatory program. There are two special cases to be noted, where the RVCA has recognized that the available flood risk mapping over-estimates the flood susceptible area to some degree, and required revisions have yet to be completed: Kemptville Creek: County Road 43 to Oxford Mills Dam Hydrologic analysis undertaken during the Kemptville Creek Watershed Planning process demonstrated that earlier flood plain mapping studies (completed in 1972 for the reach from County Road 43 to Hurd Street, and in 1983 for County Road 43 to the CN railway crossing, north of Oxford Mills) over-estimated the 1:100 year flood discharge and associated flood levels along the Creek. This resulted mainly from the earlier studies’ reliance on regional flood frequency analysis methods, as historical peak flow data were insufficient to allow the use of single station frequency analysis at the time. Single station frequency analysis of the historical streamflow record (now 35 years in length) on Kemptville Creek, supports a considerably lower estimate of the 1:100 year discharge than was adopted in the earlier flood risk mapping studies. RVCA has applied the updated 1:100 year flow estimate in the available hydraulic modeling to generate revised flood levels for use in its ongoing flood plain management efforts. RVCA intends to generate updated flood risk mapping along the watercourse, but in order to do so, updated topographic mapping of suitable quality is required, but is not available. Until suitable topographic mapping is available, the existing flood risk mapping is being applied for the purposes of delineating the regulation limits, with confidence that the resulting regulation limits will have captured the areas that will be shown to be flood susceptible in future updated flood risk mapping. However, in the administration of the regulation, the RVCA make use of revised (lower) flood level estimates associated with the updated 1:100 year flood discharge estimates. 34 35 Tay River: Tay Marsh to Perth Basin The regulation limits for this reach of the Tay River have been plotted based on flood lines generated in a 1981 flood plain mapping study (plus the nominal 15 metre allowance). In that study, the 1:100 year water surface profile was based on a conservative assumption that stop logs would be left in place in the sluiceways of the Beveridges Dam (which controls water levels on the Tay Marsh) throughout a flood event. Sensitivity analysis conducted during the 1981 study showed that the flood levels within the upstream Town of Perth are not sensitive to the assumed water level at the downstream dam, but more recent hydraulic analysis has demonstrated that this assumption gives rise to higher water levels along agricultural lands between the Tay Marsh and the Town limits than would result if the sluiceways were assumed to be fully opened when the peak flood flows occur. RVCA will be consulting with officials of the Rideau Canal – Parks Canada (owner/operator of the Beveridges Dam) to confirm that its regular practice is to strip logs from the Dam during flood events to minimize its influence on upstream water levels. An adjusted 1:100 year water surface profile for this reach of the Tay River, derived from the available hydraulic model with the most appropriate assumption with respect to the stop log setting at the dam, will then be used by RVCA in its administration of the Regulation. For all stream reaches, digital flood lines were used in the process of delineating regulation limits, and were obtained in one of two ways: Flood lines generated in Autocad format during the original engineering studies have been imported directly into the RVCA’s GIS system (ARCGIS-based), with necessary checks for scale, projection system, etc. Elsewhere, where the flood risk mapping was completed before digital mapping came into everyday use, the flood lines have been digitized from high resolution scans of the older flood risk maps, again after performing quality control checks to ensure that the projection of the original flood plain mapping was consistent with the projection system used for the regulation limits mapping. Spill Sections The available flood risk mapping identifies “spill sections” – locations where the estimated water surface elevation for the regulatory flood on a watercourse is higher than the lowest portion(s) of the “height of land” between adjacent subwatersheds. During the regulatory flood event, floodwaters are expected to spill from the flood plain of one stream into an adjacent subwatershed across these “spill sections”. Water surface elevations along the path taken by the “spilled” flood waters are not as high as the flood level above the spill section, since the rate of flow across the spill section is very small compared to the total streamflow, and is not obstructed by any hydraulic control located further downstream along its path. In the process of delineating regulation limits, known or identified spill sections have been treated as being equivalent to 36 flood lines; the regulation limits do not include lands along the overland flow pathways taken by the “spilling” flood waters. Regulations Limits beyond the Limits of Available Flood Risk Mapping “Limits of Study” are plotted at the upstream and downstream ends of engineered flood risk maps, at the edges of available topographic mapping coverage, or where the flood plain limits could not be delineated based on the available hydrotechncial analysis. For the purposes of conforming with Ontario Regulation 97/04, the regulation limits on either side of the stream system are truncated at the upstream limit of the available flood risk mapping but they do not “close” across the flood plain/valley system. A standard notation has been placed on the mapping to indicate that hazardous lands, river and stream valleys, or wetlands may extend upstream of and beyond the plotted regulation limits, but their boundaries have yet to be delineated. RVCA intends to update the regulation limits mapping over time, and will extend the delineation of regulation limits further upstream on river and valley systems, as supporting technical information (such as topographic mapping and flood risk mapping) becomes available. Consideration of Meander Belt Criterion The Guidelines for Developing Schedules of Regulated Areas require, for systems with “nonapparent” stream valleys, that the regulation limits be based on flood risk or erosion risk whichever represents the greater hazard in terms of the land area that is affected. Areas that are subject to an erosion hazard are to be defined by an estimated meander belt allowance. The Guideline recommends that the width of the meander belt should be assumed to be “20 times the bank full width of the watercourse”, in the absence of geomorphological assessments. Geomorphological assessments have not been undertaken on the stream systems for which RVCA has delineated regulation limits. The “20 times bank full width” criterion, when applied to streams without apparent valley systems in RVCA’s area of jurisdiction, yields meander belt widths that are considered excessive and difficult to justify. From RVCA’s local experience, overbank flooding is generally considered to be of greater concern than streambank erosion on such streams, in terms of risks to property and public safety on streamside lands. To illustrate, consider the reach of the Jock River between Greenbank Road and Moodie Drive in South Nepean. In plan view, the stream exhibits a gentle meandering pattern, and its bankfull width is generally between 35 and 50 metres. The default meander belt width (20 times bankfull width) would vary between 700 and 1,000 metres. For the stream to move laterally to the edges of the resulting meander belt during a 100 year period would require the annual rate of erosion to be in the order of 3 or 4 metres per year, which is far greater than has been observed on the stream. To confirm this observation an analysis of aerial photography taken in 1953 and 2002 (1:5,000 scale) has been undertaken. At three representative cross-sections on the outside bends of the Jock River, the position of the riverbank measured in relation to permanent features on the landscape that are identifiable in both photos, has moved approximately 5, 10 and 0 metres, respectively over a 49 year period, or 36 37 at average annual rates of 0.1, 0.2 and 0.0 metres per year, respectively. The mean rate of riverbank migration, across the three “sample sites” has been 0.10 m/yr. Similar results were obtained by air photo analysis of reaches of the Tay River and Steven Creek which, when observed from above, could be thought of as exhibiting meandering behaviour. Mean annual rates of migration of 0.17 m/yr and 0.03 m/yr were measured for the Tay River (3 sample sites) and Steven Creek (4 sample sites), respectively. A number of factors that can contribute to estimating error have not been accounted for in this analysis, including differences in the stream bank vegetation cover, time of year, water level, light/shadow conditions, etc. between the images from 1953 and 2002. The amount of streambank migration that is inferred from the air photo analysis is very likely in the same order of magnitude as the estimating error. However, the air photo analysis provides qualitative evidence in support of RVCA’s view that that the “twenty times bankfull width” criterion is generally inappropriate for use on the stream segments where regulation limits have being delineated, considering the following: stream systems with non-apparent valleys within RVCA’s area of jurisdiction tend to be located on relatively flat landscapes on deep surficial deposits of stiff silty clays, or on limestone plains with thin till overburden. The cohesive clay and till soils, or exposed bedrock over which the streams are flowing are relatively resistant to erosion by fluvial action compared to non-cohesive sand and gravel substrates on which actively meandering streams are more typically seen; the natural geomorphology of local streams is governed more by the contours of erosion resistant strata in the subsurface than by the dynamics of loose sediment scouring, transport and deposition. the watercourse reaches for which regulation limits have been delineated are higher order watercourses whose main channels were established through fluvial action under much higher flow regimes following the retreat of the ancient Champlain Sea, and long before artificial regulation of the flows and levels by means of dams and reservoirs. Generally, the present geology, hydrology, and hydraulics are such that streamflows have insufficient energy to drive substantial or fast-paced change in the plan form of the channels in question. at many locations, structural alterations of the watercourses – including channelization for land drainage or navigation purposes, conduits at transportation crossings, weir and dams for water level control purposes, substrate armouring at buried utility crossings, and streambank armouring for erosion control purposes – have had a constraining effect that prevents the streams from meandering in a “natural” way (even at the extremely slow pace that is possible in the relatively erosion resistant substrate) future land development in the watershed, as identified in municipal official plans for the current planning horizon, is not expected to significantly alter the hydrologic regime of the subject watersheds and, in the longer term, the implementation of watershed-based 38 stormwater management strategies should ensure that land use change will be managed so that it does not adversely affect the geomorphological stability of stream systems. Therefore, for the stream reaches without apparent valleys and for which regulations limits have been delineated as of the date of this brief, it is the RVCA’s opinion that the dominant hazard is flooding and regulation limits based on 1:100 year flood lines plus a 15 metre allowance adequately capture the areas that could potentially be affected by hazards related to streambank erosion. As the RVCA extends the delineation of regulation limits to include additional stream reaches in the future, the application of the meander belt criterion (in the absence of geomporphological assessments) will be considered on a reach by reach basis, recognizing that on lower order headwater streams, the meander belt criterion could be the dominant criterion, depending on local geological and hydraulic conditions. Application of the “Up to 15 Metre Allowance” The Guidelines allow the Conservation Authority to apply discretion in the application of the “up to 15 metre allowance” beyond the 1:100 year flood line or the meander belt allowance (whichever is greater). The technical basis and justification for including the additional allowance in the regulated area beyond the identified hazardous area is related to the fact that hazard land delineations are approximations, with many factors contributing to the inherent margins of error. The permission granting provisions of the regulation allow carefully planned developments and alterations that are proposed in the zone between the confirmed hazard limits and the regulation limit. The RVCA has applied the 15 metre allowance consistently in the delineation of regulation limits but will advise its member municipalities and other interested parties to identify hazardous lands, for the purposes of Official Plans and Zoning instruments based on the delineated hazards, as opposed to the regulation limits. This is consistent with the guidance provided in the Guidelines for Developing Schedules of Regulated Areas, where it is noted that “standard allowances and requisite features are not hazardous lands”. 38 39 Table 2 – Engineered Flood Risk Mapping in the RVCA Area of Jurisdiction Watercourse Reach Consultant Year Completed 1984 Standards Comment FDRP Hydrologic analysis reviewed in 1996 re: Britannia Village flood control initiative Ottawa River Shirley’s Bay to Rockland MacLaren Plansearch Rideau River Rideau Falls to Hog’s Back Falls Hog’s Back Falls to Roger Stevens Rd. Roger Stevens Rd. to Burritt’s Rapids Burritt’s Rapids to Smiths Falls (Old Sly’s Locks) Smiths Falls (Old Sly’s Locks to Poonamalie Dam) Rideau River to Richmond Fen Richmond Fen to Ashton Dam Rideau River to Malakoff Road Rideau River to Road 43 Road 43 to CNR Railway A.J. Robinson 1984 FDRP M.M. Dillon 1989 FDRP Robinson 2003 FDRP J.F. MacLaren 1976 Pre-FDRP Ortho-photo base does not include topographic contours J.F. MacLaren 1979 Pre-FDRP Ortho-photo base does not include topographic contours PSR Group& J.F Sabourin PSR Group & J.F. Sabourin Robinson 2005 FDRP+ Base mapping specifications exceed standards 2005 FDRP 1995 FDRP Robinson 2003 FDRP J.F. MacLaren 1983 Pre-FDRP Road 43 to Hurd Street J.F. MacLaren 1972 Pre-FDRP Tay Marsh to Glen Tay Fenco 1981 Pre-FDRP Jock River Steven Creek Kemptville Creek Tay River Q100 over-estimated; no topographic contours on orthophoto base Q100 over-estimated; base mapping out of date Assumptions regarding Beveridges Dam operation under review 40 Apparent Stream Valleys For watercourses that occupy apparent stream valleys, the regulation limits have been placed 15 metres upland of the position of the dominant hazard or feature, amongst the following: The 100 year flood line 15 metre toe erosion allowance plus stable slope allowance - where the toe of slope is within 15 metres of the streambank. stable slope allowance – where toe of slope is more than 15 metres from the streambank, and the existing slope is potentially unstable top of slope – where the toe of slope is more than 15 metres from the streambank or where it is demonstrated that is no active erosion, and where the existing slope is considered to be stable Methods for delineation of each of the above mentioned setbacks have been in accordance with the Guidelines for Developing Schedules of Regulated Areas, and are summarized as follows: 100 Year Flood Line Flood lines have been taken from previous engineering studies, as in the case on non-apparent systems. Stable Slope Allowance The guidelines recommend applying a 3:1 stable slope allowance, unless the soils of the valley walls consist of sandy or sensitive marine clays, where a 5:1 stable slope allowance allowance is recommended. RVCA has referred to the “Quaternary Geology of Ontario” and assumed that all slopes within areas of Glaciomarine and Marine Deposits: Silt and Clay (Unit 26 on Map 2556 of the Series) can exhibit behaviour that is typical of slopes in sensitive marine clay. The stable slope allowance of 5:1 is applied in those areas. RVCA recognizes this to be a conservative assumption, since the sensitivity of clays and silty clays within that mapped unit is highly variable. RVCA is aware of many locations in those areas where site-specific geotechnical studies analyses bu qualified experts have concluded that existing slopes that are steeper than 5:1 have adequate factors of safety. However, from a policy point of view, the effect of the regulation is to require that approvals be obtained for developments adjacent to existing slopes – not to prohibit development - and in general, approvals for development between the slope crest and the regulation limit will be granted if the proposals are supported by suitable geotechnical analyses. 40 41 Details of the mapping methodology are as follows: a. The position of the water’s edge (the streambank) was determined using available mapping and aerial photos. For watercourses where contours from AutoCad drawings were used, the water’s edge is defined as the first contour above the target navigation level (on navigable sections of the Rideau River) or a defined water level within the AutoCad drawing (where an elevation contour crosses the watercourse). This estimate of the position of the water’s edge was then checked for reasonableness against available aerial photos considering the time of year the photos were flown. b. Since information is not readily available at all locations to determine if the existing streambank is eroding or resistant to erosion, it has been assumed that all streambanks are potentially eroding and require a 15 metre “toe erosion allowance”. It is acknowledged that this is a conservative assumption and results in a larger regulated area at the slope crest than may be necessary in locations where streambank armouring has been completed or where the banks are naturally erosion resistant. Again, the local policy of the RVCA will be to permit development within the zone between the slope crest and the regulation limits, provided that suitable technical analysis is completed and the minimum riparian zone setbacks (30 metres from streambank and 15 metres from crest of slope) are respected. During the technical analysis of permit applications, the condition of the streambank and toe of slope will be taken into account. c. Where the toe of slope is within 15 metres of the existing water’s edge and the potential for toe erosion is assumed, the stable slope allowance is plotted from the identified toe erosion allowance of 15 metres to the point where a 3:1 slope (5:1 in sensitive marine clays) intercepts the table land elevation (see Figure 1). At multiple locations (crosssections) along the valley wall, the stable slope allowance is plotted as shown in Figure 1, and then the points where the stable slope allowance intercepts the table land elevation are connected in plan view to delineate the potentially hazardous lands. Where the toe of slope is greater than 15 metres horizontally from the waters edge, the stable slope allowance is calculated from the existing toe of slope to the point where a 3:1 slope (5:1 in sensitive marine clays) intercepts the table land elevation (see Figure 2). 42 Stable Top of Slope Top of Slope Regulation Limit < 5:1 Waters Edge <5:1; >3m in height 15m Allowance Navigation or Normal Water Level 15m Toe Erosion Allowance 3:1 Stable Slope Allowance (5:1 if sensitive marine clay) Figure 1: Cross section showing stable slope allowance where toe of slope is within 15m of the waters edge. Top of Slope Stable Top of Slope Regulation Limit <5:1; >3m in height Waters Edge Navigation or Normal Water Level < 5:1 15m Allowance Toe of Slope 3:1 Stable Slope Allowance (5:1 if sensitive marine clay) >15m Figure 2: Cross section showing stable slope allowance where toe of slope is greater than 15m from the waters edge. d. Where incised ravines have cut into the primary valley walls on minor streams that are tributary to the main watercourse, the regulation limit has been plotted as outlined above (applying the toe erosion allowance and stable slope allowance) on the lower portion of the ravine, up to the point on the ravine where its invert is three metres below the adjacent table land. On the upper portion of the ravine (where its depth is less than 3 metres), the regulation limit has been positioned 15 metres upland from the top of slope, as interpreted from the available contour mapping. 42 43 Top of Slope As noted previously, where it is known that the toe of the slope is armoured or located more than 15 metres horizontally from the streambank, and that the existing slope face is stable, the regulation limits would be positioned 15 metres upland from the existing crest of slope. To apply this criterion requires information on the state of toe erosion as well as the stability of the slope, which is not available for all locations. As noted above, the RVCA has conservatively assumed that the toe of all valley wall slopes that are within 15 metres of the watercourse will eventually be prone to toe erosion, and that all valley wall slopes that are steeper than 3:1 (5:1 in sensitive marine clays) are potentially unstable. Thus, the “top of slope plus 15 metres criterion” only applies in locations where the valley wall is known to be composed of exposed bedrock (e.g. portions of the Ottawa River shoreline/valley), or on the uppermost portions of tributary ravines where the depth of the ravine is less than 3 metres, as discussed above. Inclusion of Wetlands in the Regulation Limits Mapping An expressed objective of the amendments to Section 28 of the Conservation Authorities Act which gave rise to the “generic regulation” process has been to make the regulations of Conservation Authorities consistent with and complementary to the Provincial Policy Statements (PPS) under Section 3 of the Planning Act, which governs land use planning in the Province. The Provincial Policy Statement requires that development and site alteration shall not be permitted in provincially significant wetlands (as identified by the Ministry of Natural Resources) and that such areas be identified in municipal official plans. The Policy also requires that development and site alteration on lands that are adjacent to provincially significant wetlands be evaluated with respect to the potential for negative impacts on the ecological functions of the wetlands, before proceeding. To satisfy these objectives, the RVCA has included in its regulation limits mapping, any provincially significant wetlands that have been identified in approved municipal official plans. The wetland boundaries have been extracted from the MNR’s Natural Resources & Values Information System (NRVIS) for use in the mapping, and a 120 metre allowance has been applied upland of the wetland boundary to establish the regulation limits. 44 Future Extension of Regulation Limits Mapping RVCA has focused its efforts to date on delineating regulation limits on river and stream reaches for which flood hazards have been identified in engineered flood line mapping studies, and on Provincially Significant Wetlands that are recognized in municipal official plans. The Regulation Limits that have been delineated so far only describe some of the lands within the RVCA area of jurisdiction to which the “Development, Interference with Wetlands, Alteration to Shorelines and Watercourses Regulation” can apply. RVCA will continue, over time, to delineate regulation limits on additional hazardous lands, river and stream valleys and wetlands with whatever resources are available and can be allocated to the task. It will be necessary to identify priorities amongst the many watercourses, inland lakes and wetlands in the RVCA area of jurisdiction for which regulation limits will eventually be needed. It may also be necessary to select additional methods for delineating regulation limits for some river and stream systems or wetland features. For example, RVCA’s methods for estimating flood hazard limits in the absence of engineered flood lines on a given river or stream system and the allowance to be applied as “other area” adjacent to locally significant wetlands have yet to be determined. The selection of priority areas for additional regulation limits mapping, and the development of additional methods will be done in consultation with local municipalities and other stakeholders, and will take direction from watershed and subwatershed planning initiatives, wherever they have been undertaken. If and when the Regulation Limits Mapping is amended to include additional areas, this brief will also be revised and updated as required to document any modifications in the methods used by the RVCA in the delineation of the regulation limits. 44