Stormwater Facilities. The stormwater management facilities shown and labeled in Attachment A must be maintained as follows: All stormwater retention, detention and treatment basins must be inspected at least once a year to determine that basin retention and treatment characteristics are adequate. A storage treatment basin will be considered inadequate if sediment has decreased the wet storage volume by 50 percent or dry storage volume by 25 percent of its original design volume. Based on this inspection, if a stormwater basin requires sediment cleanout, the basin will be restored to its original design contours and vegetated state within one year of the inspection date. A log of the dates, conditions and results of the inspections conducted in accordance with the schedule, as well as corrective actions taken to response to inspection results and results of corrective actions taken, must kept onsite and made available to the District and its designated agents with reasonable notice during normal business hours. Volume control facilities and contributing drainage areas must be inspected every three months during the operational period (between spring snowmelt and first substantial snowfall) and monitored after rainfall events of 1 inch or more to ensure that the contributing drainage area is clear of litter and debris, inflow pipes and overflow spillways are clear, inlet areas are clean, undesirable vegetation is removed and there is no erosion impairing or threatening to impair the function of a facility. If sediment has accumulated in a infiltration feature, within 30 days of inspection deposited sediments must be removed, the infiltration capacity of the underlying soils must be restored, and any surface disturbance must be stabilized. Inspection must ensure that sediment traps and forebays are trapping sediment and that more than 50 percent of the storage volume remains, the contributing drainage area is stable (i.e., no erosion is observed), and inlets and outlet/overflow spillways are in good conditions with no erosion. Maintenance techniques used must protect the infiltration capacity of the practice by limiting soil compaction to the greatest extent possible (e.g., by using low-impact earth-moving equipment). In addition, rain gardens must be kept clean of excess sediment and debris. Healthy plant growth must be maintained in rain gardens by removing dead vegetation in the spring of each year, and the top two to five inches of media must be removed and replaced every thre...
Stormwater Facilities existing stormwater features shall not be altered, modified or expanded, and there shall be no construction of new stormwater xxxxxx, stormwater detention or retention facilities or ditches within the Environmental Site without prior written approval from the DWM, in addition to any authorizations required by the DWRM or the WMD. FDEP DWM will timely respond to such requests to review stormwater plans. Nothing herein shall exclude Railroad from conducting routine maintenance or clearing of existing stormwater facilities or temporarily modifying stormwater facilities as part of emergency response efforts (derailment, etc.).
Stormwater Facilities. 4-1 Purpose
Stormwater Facilities. 4-1 Purpose 30 4-2 Summary 30 4-3 Pipe Systems 32 4-3.1 Pipe Materials 32 4-3.2 Pipe Sizes, Slopes and Velocities 32 4-3.3 Pipe Location 33 4-3.4 Pipe Alignment/Cover 33 4-3.5 Manholes, Catch Basins and Curb Inlets 33 4-3.6 Frames/Lids/Grates/Covers 34 4-3.7 Restrictor and Orifice Devices 35 4-3.8 Debris Barriers and Safety Access Restriction Grate 35 4-3.9 Pump Stations and Forcemains 35 4-3.10 Culvert Design Criteria 35 4-3.10.1 Headwater 35 4-3.10.2 Ditch Inlets and Outlets 35 4-3.11 Outfall Design Criteria 36 4-3.11.1 General 36 4-3.11.2 Outfall Systems Traversing Steep Slopes 36 4-3.12 Open Channel Design Criteria 36 4-3.12.1 Constructed Channel Design Criteria 37 4-3.12.2 Riprap Lining Design 38 4-3.12.3 Filter Blankets and Riprap Geotextile 38 4-3.13 Drainage Easements and Access 38 4-4 Control Water Quality 38 4-4.1 How can site design reduce pollution? 39 4-4.2 What is required? 39 4-4.3 Site Uses / Characteristics Requiring Source Control BMPs 39 4-4.4 General principles of source control 40 4-4.5 NPDES/WPCF Industrial Stormwater Permits 40 4-5 Perform Erosion Control 40 4-6 Provide for Maintenance and Operation 40 4-6.1 Dedication Submittal Requirements 41
Stormwater Facilities. 4-1 Purpose
4-2 Summary
4-3 Pipe Systems
Stormwater Facilities. Stormwater facilities will conform to the “Cascadia Master Drainage Plan (1998)”, and the update to the Master Drainage Plan provided in Appendix F of the SEPA EIS Addendum for Amended Phase 1 (August 2013) which calls for a system of regional infiltration facilities, detention ponds and a master system of overflow/bypass pipes and channels.
Stormwater Facilities. (a) The CDD shall be responsible for all stormwater facilities, including inlets, pipes, swales, and drainage structures within the City ROW. The CDD shall apply for a Right-of-Way Permit prior to any construction work within the City ROW.
(b) The CDD shall be responsible for interface drainage ways between man-made stormwater drainage systems and natural drainage systems.
(c) The CDD shall be responsible for ensuring that all stormwater systems related to private property are properly maintained, including: lakes; stormwater treatment ponds; and conveyance and control facilities.
(d) The CDD shall be responsible for ensuring maintenance meets any permit conditions.
(e) The CDD shall provide all Stormwater Reports meeting NPDES permit requirements to the City.
Stormwater Facilities. Pond-to-pond connecting stormwater sewers and detention ponds, as shown on the Development Plans (the “Stormwater Facilities”), will be constructed by ProLogis at its sole cost and expense to, in accordance with all applicable law and governmental orders in a good workmanlike manner consistent with prevailing and commonly accepted practices, service the NS Parcel. In connection with the Stormwater Facilities, ProLogis shall obtain at its sole cost and expense all permits, consents and approvals required by law therefor including as may be required to be obtained from the Illinois State Toll Highway Authority for discharge/outlet from the Stormwater Facilities into the stormwater/drainage system of the Illinois State Toll Highway, or to perform any work on, under upon or across land owned or operated by the Illinois State Toll Highway Authority. As part of the aforedescribed obligation, any provision of this Agreement notwithstanding, ProLogis, at its sole cost and expense, will furnish any insurance or bonding required by the Illinois State Toll Highway Authority.
Stormwater Facilities. Pond-to-pond connecting stormwater sewers and detention ponds will be constructed by ProLogis in accordance with all applicable law and governmental orders in a good workmanlike manner consistent with prevailing and commonly accepted practices, to service the NS Parcel. The Stormwater Facilities shall be installed in accordance with civil engineering drawings prepared by Jacob & Xxxxxx Associations, Inc., identified as follows: Sheet C1 (Cover Sheet), Sheet C2 (Typical Sections), Sheet C3 (Master Grading Plan), Sheet C4 (Existing Conditions & Removal Plan), Sheet C5.1 (Mass Grading Plan), Sheet C5.2 (Mass Grading Plan), Sheet C5.3 (Mass Grading Plan ), Sheet C5.5 (Mass Grading Plan), Sheet C6 (Storm Water Pollution Prevention Plan), Sheet C7 (Specifications), and Sheet C8 (Details), all dated 3-17-11.
Stormwater Facilities. The Pond to be constructed by Owner will include stormwater facilities identified in the Approved Site Plan as Outlet 1, Outlet 2, and Emergency Overflow (collectively referred to as the “Outfall Structure”). City, at its expense, may install ancillary stormwater facilities (e.g. flow measuring device).
