HANDBOOK for MAINTAINING FLOOD PROTECTION PROJECTS

Transcription

1 HANDBOOK for MAINTAINING FLOOD PROTECTION PROJECTS BUREAU OF WATERWAYS ENGINEERING AND WETLANDS 3100-BK-DEP2734 Rev. 4/2014

2 INTRODUCTION A program of regular maintenance is the key to ensuring the performance and service life of your flood protection project. Keeping your project in as-built condition will provide continued flood protection benefits to your community. The operation and maintenance program for your project must include a maintenance plan. Developing, funding and implementing your plan begin with bringing focus to the project and designating one person to manage the program. That person must have knowledge and understanding of the project, a passion for flood protection and the ability to direct the program. Effective maintenance can be achieved with project monitoring and operations preparedness. Through an effective operation and maintenance program, Pennsylvania sponsors are achieving high levels of condition and performance for their projects. As your partner in flood protection, DEP is committed to working with you to keep your project ready to perform. This manual will enable you to better understand what is required to maintain a flood protection project and the commitment necessary to provide flood protection to your community. On behalf of DEP and its Flood Protection program, we would like to acknowledge the U.S. Army Corps of Engineers and the New York State Department of Environmental Conservation for providing information used in the development of this manual.

3 TABLE OF CONTENTS Page Maintenance Goal... 1 Mission... 1 Major Operation and Maintenance Actions Required by the Sponsor 1 DEP s Role... 2 Other Sponsorship Responsibilities... 2 A Maintenance Plan... 2 Why Plan?... 3 What is Enough Maintenance?... 3 What Does Operational Preparedness Have to do with Maintenance? 3 Levees... 5 Depressions... 5 Erosion... 5 Slope Stability... 6 Cracking... 6 Seepage or Saturated Areas... 6 Animal Burrows... 6 Unwanted Growth... 7 Encroachments... 8 Cover... 8 Cover Removal... 8 Sowing... 9 Access... 9 Debris Removal... 9 Riprap...10 Stone Riprap Protection...10 Gradation of Stone Riprap...10 Gradation of Filter Blanket Layer...11 Geotextile Fabric Layer...12 Selection...12 Placement...13 Grout...14 Concrete Structures...14 Alignment...15 Cracks in Concrete...15 Settlement...16 Joints...16 Concrete Surface Repairs...17 Cracks at Fence Posts...18 Concrete Repair Material...18 Unwanted Growth...19 Obstructions...20

4 Drainage Structures Drainage Structures at Levees Drainage Structures at Concrete Walls Gate Manufacturers Inlet/Outlet Channel Inlet/Outlet Structure Inlet Structure Grating/Metalwork Sluice Gates Operator Pipe Flapgates Drainage Slots Debris Basins Sedimentation Obstruction Erosion and Stability Riprap Encroachment Unwanted Growth Cover Earth Channels Sedimentation Obstructions Erosion and Stability Riprap Encroachment Unwanted Growth Cover Closure Structures Sandbags/Sand Stoplogs/Hardware Exercises and Drills Pumping Stations Manual Operation Maintenance Standards Control System Lubrication Exercises Dams Requirements for Maintaining Your Flood Protection Project Flood Protection Projects Definition and Terms

5 MAINTAINING FLOOD PROTECTION PROJECTS Maintenance Goal The maintenance goal for sponsors of flood protection projects, by agreement with DEP, is to develop, implement and manage an effective maintenance program for the project that will continue to provide flood protection in the community. Maintenance standards found in this manual will ensure proper performance throughout the successful life of your project. Mission The mission for sponsors is to keep the flood protection project in asbuilt condition with an acceptable condition rating through a program of regular maintenance and minor repairs. The project should be ready to perform during the next high water event. Major Operation and Maintenance Actions Required by the Sponsor An effective operation and maintenance plan can keep a project in acceptable condition and ready for the next high water event. Major actions required by the sponsor to keep the project in a state of readiness include: Removing debris from trashracks; Removing sediment from debris basins after each event or when basins are half-filled; Maintaining operational flap gates and sluice gates; Maintaining good grass cover without unwanted growth; Keeping channels free from obstructions (debris, trash and sediment); Ensuring that the project is not encroached upon by others; Preventing any action that requires excavation of a levee or boring pipes through a levee; Preventing construction or location of buildings, fences, trees, bushes or poles on project lands; Conducting exercises and drills including the installation of closure structures; and - 1 -

6 Including the operation plan for the project in the community s emergency operations plan. DEP s Role Establish maintenance requirements so that sponsors have needed information to keep their projects in as-built condition; Inspect projects annually (DEP and/or the Army Corps of Engineers); Provide technical assistance that will enable sponsors to successfully manage their projects and extend the project s service life; Issue manuals, newsletters and fact sheets that aid in the operation and maintenance of the project; Coordinate exercises and drills; Evaluate project operation and maintenance plans; Enhance the performance and reliability of flood protection projects to function as designed during a high water event through a program of major repairs, rehabilitation and replacement; Train citizen flood project monitors; Strengthen the partnership with sponsors to establish an effective community-based operation and maintenance program that provides for the continuation of flood protection benefits. Other Sponsorship Responsibilities Flood protection levees, channels and walls must not be encroached upon or altered. The protected community (the sponsor) is the caretaker of the project lands. The sponsor ensures that the project will continue to provide the designated level of flood protection for future generations through an effective operation and maintenance program. A Maintenance Plan A maintenance plan is the development, planning, funding, scheduling and implementation of a course of action that identifies a level of maintenance to be performed. Knowledge and understanding of the project s condition and how it performs is known by reviewing the annual inspection report and by regularly monitoring the project before, during and after high water events

7 Why Plan? The readiness of the project to perform during a high water event is dependent upon the level of maintenance being performed by the sponsor and also the project s condition at the time of a high water event. Your project is designed to perform at a high level, and it will function as designed during high water if it is maintained in as-built condition through a program of regular maintenance. What is Enough Maintenance? Enough maintenance is dependent upon the commitment the sponsor makes to flood protection, knowledge of the condition of the project and the history of the project s performance. The successful performance of the project can be achieved through a program of regular maintenance, efficient operation and project monitoring. What Does Operational Preparedness Have to do with Maintenance? Operational preparedness provides a strategy for operations before, during and after high water events including planning and conducting exercises (before the high water), actions and emergency response actions (during high water) and recovery (after high water). Maintaining your project at a high level, combined with a plan for project operations, will ensure the successful performance of your project. Requirements for project operations are described in the Handbook for Operating Flood Protection Projects. LEVEES CHERRY TREE - 3 -

8 SAYRE DANVILLE - 4 -

9 MAINTENANCE REQUIREMENTS FOR FLOOD PROTECTION PROJECTS Levees Levees are a common feature of many local flood protection projects and are designed to protect against flood flows. They are constructed of well-compacted, relatively impervious soil to minimize seepage. The structural integrity of levees must be maintained at all times. Proper maintenance of levees insures their overall condition and provides the level of flood protection for which the project was designed. A regular maintenance and repair program is required to keep the project functional for the next high water event, whenever it occurs. During the inspection of your flood protection project, special attention should be given to the following maintenance items: Depressions Erosion Levees should be maintained to the shape and grade as constructed. All low areas found on the levee slopes or on top of the levee that ponds water should be filled and brought to grade with impervious soil. Topsoil and sod should be removed, and the existing levee surface should be roughened before impervious type soil is added in approximately six inch layers. It should then be compacted by hand or mechanical method and brought back to its original shape. The area should then have the topsoil replaced, seeded and mulched. All erosion gullies should be brought back to the original grades. The ground should be roughened, then backfilled with impervious soil. Backfill material should be thoroughly compacted by hand or mechanical methods, then placed in six inch layers to the original alignment and elevation. The area should then be covered with the appropriate size rock

10 Slope Stability Cracking Any deep-seated sliding, a movement of a portion of the levee down the slope towards the toe, requires removal and replacement of that section of the levee or stabilization of the levee toe with a soil or rock berm. Contact DEP for technical assistance and request an immediate inspection of the levee. All cracks on or near the top of the levee with a length equal to or greater than the levee height and/or cracks along the slope may cause movement of levee material or bulging of the levee. Contact DEP for technical assistance and request an immediate inspection of the levee. Seepage or Saturated Areas When soil on the land side toe of the levee becomes wet and spongy during high water, seepage or saturated areas will develop. This condition must be checked often to determine if seepage flow is increasing or muddy. If the seepage is carrying soil or if longitudinal cracks appear, a movement of a portion of the levee down the slope towards the toe may occur. Such a condition may cause a levee breach. Contact DEP for technical assistance and request an immediate inspection of the levee. Also, seepage through the levee or its foundation may cause ponded water to occur. When the water is up on the water side of the levee, and a boil or water begins seeping from the tow on the land side, a ring embankment should be constructed around the boil with sandbags. The embankment should be raised until the water stops rising in the ring levee. A supply of sandbags for this effort should be maintained. Contact DEP for technical assistance and request an immediate inspection of your levee. Animal Burrows Measures should be taken to remove burrowing animals from the levee. Upon removal of animals, the burrows should be excavated and backfilled with a cementitious flowable backfill material

11 The cementitious flowable backfill material may have the following mix proportions, per cubic yard: a. Type I Portland Cement, 725 lbs. b. Fine masonry sand, 2,100 lbs. c. Clean water, 46 gals. After the mixture is thoroughly mixed, it should be pumped into the burrow entirely filling the void. Unwanted Growth Trees, brush cover and woody vegetation cannot be allowed to grow on the levee. Care must be used to not denude the entire levee of the protective grass cover. Herbicides should be used to assist in controlling the growth on levees after brush and crown vetch has been removed. Herbicides should be carefully selected for safe use near a stream where over-spraying or leaching would cause the chemical to enter the stream. Herbicides should be applied by or under the direct supervision of a State Certified Pesticide Applicator and, in all cases, the manufacturer s label recommendations must be rigidly followed. Advice concerning appropriate herbicides may be obtained from: Pa. Department of Agriculture Bureau of Plant Industry Division of Health and Safety Pesticides 2301 North Cameron St. Harrisburg, PA FAX Ornamental or other trees should not be planted on levees or elevated floodplains because the root systems penetrate the embankment and can cause plains of weakness and potential failures. Contact DEP for technical assistance and advice on other plantings

12 Encroachments Cover Operation and maintenance should not be restricted or impeded by trash, debris, excavation, structures, fill or other obstructions. On the top and land side of levees, a lawn mixture grass is used and should be mowed at least twice a year, preferably in late spring and early fall. This is done to keep the length of grass in the proper range of four to eight inches. Mowing will control the growth of weeds, trees and brush. On the water side of levees, Crown Vetch Grass Mixture is used on the slopes. A schedule should be prepared to remove the crown vetch and replace it with PennDOT Type L Grass Mix. Cover Removal Crown Vetch should be killed by spraying it with the appropriate chemicals applied by a State Certified Pesticide Applicator and, in all cases, the manufacturer s label recommendations must be rigidly followed. Advice concerning appropriate herbicides may be obtained from the Department of Agriculture in Harrisburg. After the areas to be reseeded have been denuded, they should be regraded and thoroughly tilled to a sufficient depth by discing, harrowing or other approved means to remove unwanted clumps of sod and grass and roughen the surface. Apply fertilizer and lime at a rate of 750 pounds and 4,000 pounds per acre respectively, and work thoroughly into the soil to a sufficient depth to insure that the soil conditions are satisfactory for seeding. Smooth and bring the area to grade. Immediately prior to sowing, rake the soil to a depth of ¾-inch. Rake in a direction parallel to the contour lines on the slope, not uphill or downhill. Remove all sticks, stones, weeds, roots and other objectionable materials on the surface

13 Sowing Access Maintain the surface in a true and even condition while sowing the seed. On steep slopes, till the surface horizontally by roughening the area enough to break up the surface crust, eliminate irregularities resulting from soil erosion and remove all objectionable materials from the surface. The seed mix should be PennDOT Type "L" Grass Seed Mix, designated in PennDOT Publication 408. This mix is acceptable for use as a low-maintenance seed mixture. Sow the seed mixture on a calm day, by hand or by approved sowing equipment, in two applications. Use half the seed while the seeder is traveling in one direction, and use the other half while the seeder is traveling at a right angle to the first direction. After sowing, rake or drag the surface very lightly to cover the seeds. Rake only in a direction parallel to the contour lines. After sowing is completed, spread moist mulch uniformly over the entire seeded area at a rate of three tons (dry weight) per acre. Ramps that have been constructed to permit vehicle passage to the top of the levee or across the levee from the protected area to the unprotected area are to be graded as necessary to keep the roadway free from ruts and holes. Ramps are to be barricaded, chained and locked at all times to prevent unnecessary traffic. Debris Removal Remove all debris from the slopes of the levee after every high water event

14 Riprap Slope protection is provided on channel side slopes, levee side slopes or other areas where stream velocities are expected to cause loss of embankment (scour) and erosion of soil and grass cover. Slope protection can be provided by several methods including concrete slope paving, concrete injected mattresses or stone riprap protection (stone placed adjacent to each other to form a protective cover). Regardless of the method used, its purpose is to protect against scour and erosion that could lead to slope failure. Stone Riprap Protection Riprap should be kept free of woody growth, voids, displacement and deterioration. The most effective way to control brush and woody growth is through the periodic application of a chemical herbicide applied by a State Certified Pesticide Applicator. Any areas of stone riprap that have settled, moved or been damaged by erosion should be filled in with hard, durable rock of suitable size or with a six-inch filter blanket layer or a layer of geotextile fabric under the stone riprap between the soil and the rock. These sublayers allow the water to pass from the soil, yet prevent the fine soil from washing out from under the stone riprap. Gradation of Stone Riprap Riprap Placement Thickness (inches) % Lighter by Weight ,350 2,270 PennDOT Rock Lining, designated in Publication 408, for Classes 12 through 30 inch and Sizes R-5 through R-7 may be used in place of DEP riprap gradations

15 Gradation of Filter Blanket Layer U.S. Standard Sieve Size 2 ½ 2 4 #4 #20 #100 Percent by Weight Passing SLOPE PROTECTION RIPRAP SLOPE PROTECTION ALONG LEVEE DERRICK STONE ALONG LEVEE GROUTED RIPRAP SLOPE PROTECTION

16 Geotextile Fabric Layer Prepare areas where stone riprap is to be placed by excavating, trimming and dressing to conform to cross sections and slopes shown on the Drawings. Use Class 2, Type B Geotextile fabric for riprap and grouted riprap of 9 and 12-inch placement thickness. Use Class 2, Type A Geotextile fabric for riprap and grouted riprap of 18 and 24-inch placement thickness. Place the fabric on the prepared soil area in a loose unstretched condition to minimize shifting, puncturing or tearing of the fabric. Lay the fabric with the long dimension parallel to stream flow and, for protection of the entire slope, lay the fabric with the long dimension perpendicular to the centerline of the channel. Provide a minimum overlap of 12 inches at the joints, with the upstream fabric over the downstream fabric and the upslope fabric over the downslope fabric. Anchor the fabrics in place by inserting securing pins through both fabrics at the overlaps with spacing shown on the following table: Slope Steeper than 3:1 4:1 Flatter than 4:1 Securing pin spacing 2 feet 3 feet 5 feet along overlaps Selection Riprap should consist of sound durable rock insoluble in water. Stratified or easily crumbled rocks such as shales, and rocks liable to decompose in water, such as claystones, are not acceptable. Stone for riprap should be block shaped with a specific gravity of at least 2.5. Smooth, rounded stone or boulders and flat, thin, elongated and slab shaped stone are not acceptable. No more than 25 percent of the stones distributed throughout the gradation should have a length more than 2.5 times their breadth or thickness. No stone should have a length exceeding three times its breadth or thickness

17 LEVEE SLOPE PROTECTION WARREN Placement Place stone for riprap on the filter blanket or on the sheet of geotextile material, in the dry, and conforming to the lines and grades of the construction drawings. Place the stones in such manner as to produce a reasonably well-graded and uniform surface. Place stone to its full course thickness in one operation and without displacing the underlying filter material. Do not place stones in layers. The finished work will be free from objectionable pockets of small stones and clusters of larger stones. Smaller stones will be well distributed in order to fill the voids between larger stones. Do not place riprap by dumping stones into chutes or by similar methods likely to cause segregation of various sizes. Do not use a tractor equipped with a bulldozer blade, stone rake or any similar equipment. The desired distribution of the various sizes of stones throughout the mass should be obtained by selective loading of the material at the quarry, by controlled dumping of successive loads during final placing or by other methods

18 Grout Rearrange individual stones by hand or mechanical means to the extent necessary to break down bridging and to obtain a reasonably well-graded mass. Grout should consist of one part cement, two parts fine aggregate by volume and sufficient water to form a workable mix. Use Type IIA cement (conforming to AASHTO M 85) and Type A fine aggregate. Use reasonably clean water, free from vegetable matter, oil, acid, alkali, sugar or other objectionable materials. When the water source is relatively shallow, enclose the intake to exclude silt, mud, grass or other undesirable materials. Grout riprap in dry weather. Do not grout in freezing weather. Immediately prior to placing grout, thoroughly wash and wet the riprap to be grouted. Fill voids with grout by hand shoveling and rodding, or by other approved methods in such a way that the grout reaches the bottom of the riprap. Leave the top surface of the grout rough and low so that rock protrudes two inches above the grout. Do not hammer, roll or ram the stones after grouting. Remove grout if the bond has broken, and reset the stones with fresh grout. Cure the grout by keeping it continuously moist for 24 hours and protect the grout during this period from inclement weather, flowing water and other disturbances. Concrete Structures Concrete structures include: concrete channels, walls and slabs, box culverts, inlet and outlet drainage structures, wingwalls and floodwalls. Concrete structures will require repairs for erosion at joints and for cracks at fence posts caused by freeze-thaw action over time. Deterioration and erosion of channel slabs are often caused by acid mine drainage and by fine sands and gravel acting on the concrete surface. Repairs to concrete structures are made with concrete or concrete repair products

19 Alignment Concrete structures shall be on line and grade as shown on the construction drawings, with no abrupt changes at adjacent sections. Where visible, both sides and the top of the walls are to be inspected regularly for structural failure or misalignment. If any is observed, it shall be reported to DEP as soon as possible. Cracks in Concrete Any chipped or eroded areas are to be repaired immediately with the proper repair material. Minor cracks should be sealed with appropriate material to prevent water from entering the cracks and causing damage to the concrete by freezing and thawing action. Severe cracks should be reported to DEP as soon as they are noticed. CONCRETE STRUCTURES COUDERSPORT MAYFIELD BLAKELY

20 Settlement Joints Backfill should have no settlement or depressions greater than 12 inches. Repair backfill areas with impervious soil material so the backfill around structures and culverts can form an integral part of the levee or dam embankment. Place backfill in the dry and not on frozen ground, within a distance of four feet above concrete pipes; two feet above corrugated metal pipes; as necessary over culverts; adjacent to concrete structures; and within the horizontal limits of the trench. Place backfill in loose layers not exceeding four inches in depth, and compact each layer with vibratory compactor, mechanical tamper or other acceptable method. Do not use a roller or heavy construction equipment in these areas. In other areas, and where working clearance permits, backfill shall be placed in loose layers not exceeding eight inches in depth. Do not drop backfill materials, but scatter and bring up equally on opposite sides of culverts, wall, anti seepage collars and similar structures. Add water or dry the backfill materials as necessary to attain optimum moisture content during compaction. Moisture content of the pervious materials shall be such that no free water drains off and adversely affects the underlying or adjacent materials. Spread the layers evenly before compaction and thoroughly compact each layer. There should be no deterioration or displacement of expansion joint material, and no waterstop or rebar should be exposed. Joints may be resealed with several brands of non-sag elastomeric sealants that allow the joint to expand and contract

21 Concrete Surface Repairs Perform concrete repairs with a polymer-modified Portland cement mortar that will provide a minimum of 2500-psi compressive strength in two hours. For repairs greater than 1½ inches deep, add 3/8-inch cleanwashed pea gravel to the mix at an amount determined by the manufacturer so that the aggregates do not result in variations of the physical properties of the mortar. Limestone gravel is not acceptable. All surfaces to be patched shall be structurally sound, clean and free of loose debris, oils, vegetation, paints, sealers and all other contaminants. Remove all deteriorated concrete to a minimum of ¼-inch in depth. Cut edges should be square with the concrete surface. Feathered edges will not be allowed. Surfaces should be sufficiently rough to ensure a good bond. Any existing reinforcing bars that are exposed should be thoroughly cleaned. If required, existing concrete should be removed to fully expose the reinforcing bar. Sandblasting will be required if there are no other means of cleaning reinforcing bars. All surfaces should be thoroughly saturated, and freestanding excess water should be removed before applying the repair material. The material should be placed in the prepared area starting from one side of the repair and working to the other side. Work the material firmly into the bottom and sides of the repair. Level the material to the desired elevation and close up edges of the repair with a trowel. Finish the material to match the existing concrete finish. For vertical areas, trowel the material in an upward motion over the repaired area. Successive applications must be troweled against the previously placed material just prior to hardening. Build up the material to the thickness desired

22 Finish the material to match the existing concrete finish. Remove any material applied or spilled beyond desired areas. All exposed surfaces should be thoroughly saturated with water immediately after finishing. Cracks At Fence Posts All fence posts must have a cap to prevent water from entering the post, freezing and cracking the concrete. Caps can be secured with an allen screw to prevent removal. Concrete cracks that occur at fence posts should be sealed to prevent freeze/thaw conditions from occurring. In areas where concrete has broken away, the area void around the posts shall be brought back to grade with the appropriate concrete repair materials. Water to be used for cleaning, wetting and curing should be clear and free from injurious amounts of oil, acid, alkali, organic matter or other deleterious substances, and cannot be salty or brackish. All surfaces to receive modified cement mortar must be structurally sound, clean and free of loose debris, oils, vegetation, plants, sealers and all other contaminants. In all areas to be repaired, remove all deteriorated concrete as necessary to reach sound material to obtain a minimum of ¼- inch in depth. Sandblast or mechanically abrade the surface of the entire repair area to achieve the desired surface to insure a proper bond. Concrete Repair Material First identify the defect (cracks, overlays, spalls, joints) on your flood protection project, and then reference the appropriate repair system brochure or contact:

23 Sika Executive Office Regional and District Sales Offices 201 Polito Ave. Technical Assistance Lyndhurst, NJ Carnegie, PA SIKA ChemTrex, Inc. Tamms Industries Sonneborn Products 3835 State Rt Front St. Kirkland, IL Cumberland, RI Technical Assistance Five Star Products, Inc. Engineering and Technical Center 750 Commerce Drive Fairfield, CT From the repair system brochure, select the picture that best illustrates the condition of the project. Then, complete the diagnostics form to determine the severity of the damage and the future service environment. Determine the products and application methods that most effectively and economically repair the defect. Locate the service index as determined by the diagnostic form. Crossreference your picture with your service index, then choose the product and application method. Locate the Spec Builder lead sheet indicated in the systems brochure. The Spec Builder leads you to each component necessary to build your final specification. Contact DEP for technical assistance for any concrete repair larger then three feet in area or deeper than four inches and request an immediate inspection of the area. Unwanted Growth There should be no unwanted growth, grass or weeds in joints or weep holes. Trees and brush cover that exist adjacent to a concrete structure should be removed within 10 feet of the structure for inspection and so any repair can be made

24 Obstructions All debris and trash should be removed from the waterway area so it does not collect and create an obstruction downstream, reducing the waterway area. Large trees should be removed as soon as possible before they lodge under a bridge or in a culvert. Drainage Structures Drainage structures are used to transport accumulated runoff from the land side of the levee or floodwall to the stream or river side. They function mainly during normal stream flow and after the stream recedes following a storm event. Drainage structures are made up of three major parts: the inlet, the pipe or barrel and the outlet. Drainage structures are very effective for local drainage and controlling backflow but must be maintained to ensure proper operation All slide, sluice and flap gates need to be adjusted to open and close tightly. If flap gates aren t seated properly, backflow through the drainage structure can occur during high water. Be sure to thoroughly inspect flap gates when water levels recede and then at regular intervals to keep gates operational. DRAINAGE STRUCTURES OUTLET FLAP GATE GATED DROP INLET INLET SLUICE GATE

25 Drainage Structures at Levees These drainage structures consist of an inlet on the land side with a concrete headwall that a gate may be mounted on, a concrete apron in front of the headwall (to prevent erosion) and possibly a sluice gate or slide gate. The pipe or barrel, usually a concrete pipe, transports local drainage through the embankment to the river side of the levee. The outlet structure on the river side of the levee has a concrete headwall to mount a flap gate and a concrete apron in front of the headwall to prevent erosion. Drainage Structures at Concrete Walls Drainage structures consist of an inlet box with a wallmounted sluice gate on the land side. The box will have a roadway grate on top to catch local drainage and convey it to the water side. On the water side, a flap gate is mounted to the concrete wall. It may be installed in a separate chamber to shield the gate from the water flow. Gate Manufacturers Gates from the following manufacturers have been used by DEP on flood protection projects: Craft Machine Works, Inc. Rodney Hunt Company th St. 46 Mill St. Hampton, VA Orange, MA Hydro Gate Corp. Waterman Industries, Inc Broadway Road 204 Denver, CO Exeter, CA

26 Inlet/Outlet Channel The Inlet/Outlet channel shall be kept free of debris, trees and brush to ensure that drainage can enter and exit the drainage structure. Sediment may be removed only to the limits, as shown on the original project. Inlet/Outlet Structure The inlet structure, usually concrete, allows interior water to pass through the levee to the stream. It may have a manually operated slide or sluice gate that is kept in the up, or open, position to permit normal interior runoff to drain through the levee to the river. The outlet structure is usually concrete with a flap gate attached to the headwall. All concrete cracks should be sealed to prevent further damage from freeze-thaw action. All gates shall be seated correctly, greased and painted annually. Inlet Structure Grating/Metalwork Grating/Metalwork should be sound, free from any rust and regularly maintained by cleaning and painting. All hold down clips shall be in place and secured on gratings. Sluice Gates Sluice gates should be closed when a visual inspection determines that there is back flow from the stream through the drainage structure, and ponding levels on the land side of the levee are increasing. Sluice gates shall remain in the full-open position and only used as back-up gates in case of a nonfunctioning flap gate. On larger gates, wedges shall be adjusted to ensure proper seating when in the closed position. Gates shall be fully opened and closed every six months to ensure proper operation

27 Operator Pipe The manufacturers recommendations shall be followed for operating and maintaining sluice gates. Gates shall be regularly lubricated, cleaned and painted. The gate, frame and hand wheel should be cleaned and painted regularly. The stem should be cleaned and greased annually. The plastic sleeve over a rising stem should be intact and clearly marked to locate the position of the gate during opening and closing, or a counter should be located on the operator to show the position of the gate. The crank or hand wheel shall be in place, chained and padlocked to the operator or in the sponsor s possession. Non-rising stem gates shall have a cap or cover plate over the stem at the top of the operator. The appropriate hardware shall be cleaned, painted and greased. The pipe or barrel should be fully round and intact with no displacement or settlement. Sediment or debris shall be removed from the barrel to maintain the pipe capacity. Repairs should be made to the invert, or bottom, of concrete pipes when a pipe shows one inch of loss due to wear and abrasion. Concrete pipe repairs shall be made with concrete repair products that replace the lost surface with a protective wear coating (see concrete repair notes in Concrete Structures ). Contact DEP for technical assistance and request an immediate inspection of the drainage structure when corrugated metal pipe is rusted through, and also for any pipe that has separated from the inlet/outlet structure headwall

28 Flap gates Flap gates shall be fully operational when in the closed position, properly seated and free to function without obstruction from debris or sediment. Gates shall be regularly greased and maintained by cleaning and painting metal work. Cracked or damaged gates shall be replaced. The manufacturers recommendations shall be followed for maintaining flap gates. Drainage Slots Drainage slots should have no deposits or debris, and the opening should not be obstructed. Debris Basins Debris basins are provided in flood protection projects to prevent trees, floating debris and sediment from traveling downstream where such material may block bridge and culvert openings and reduce channel capacity. Debris basins intended to trap gravel and sediment are usually a widened area in the stream located at the entrance to a concrete channel. Debris basins must be cleaned and maintained so they can handle a high water event. Sedimentation Sediment is deposited in the debris basin for ease of access and removal. Remove sediment when the basin approaches one-half its capacity by visual inspection, and when deposits cause flow to be concentrated along the channel or levee slope where erosion can occur. Obstruction Remove debris that obstructs normal flows and reduces the storage in the basin after every high water event. Debris removal from the basin prevents downstream obstructions from occurring at bridge and culvert openings and prevents clogging of the channel. Erosion and Stability Erosion of the bottom of basin slopes can occur during high water. Slope erosion is identified by the loss of vegetation and

29 scour and erosion areas that extend along the slope. Placing suitable soil in the eroded area and reseeding can repair surface failures. Riprap slope protection should be placed on the bank to prevent further erosion in these areas. For large erosion areas, contact DEP for technical assistance and immediate inspection. DEBRIS BASINS WEST WYOMING SCRANTON BLAKELY

30 Riprap Riprap should be uniform in size, with no large voids. The area at the bottom of the slope must be stable, with complete coverage and no missing stones. If stones become dislodged or begin to deteriorate, they should be replaced with stones of uniform size and thickness. Encroachment Debris basins are intended to collect debris before it enters the channel. Land adjacent to the basin must be maintained and kept free from buildings and sheds to ensure the capacity of the basin and provide access to the basin. Unwanted Growth Cover All unwanted growth must be removed so debris does not collect and cause reduced waterway capacity. Brush should be removed to provide for adequate inspection and to ensure the proper operation of the channel. The function of good grass cover is to develop healthy sod that will protect the slope from scour and erosion. Earth Channels Main stream and tributary stream channels are often modified to improve their capacity for carrying flood flow. All improved channels must be maintained in such a manner as to insure their capacity to carry flood flows as designed and constructed, and to maximize the useful life of the improvement

31 EARTH CHANNELS CHERRY TREE PENN STATE ALTOONA CAMPUS

32 Sedimentation Remove sediment when the channel begins to collect and deposit enough sand and gravel to reduce channel capacity. Silt and gravel bars may be removed only to the grades and shape of the original project. Obstructions Remove all debris after a high water event that obstructs normal flows and reduces the waterway area of the channel. Debris removed from the channel prevents downstream obstructions from occurring at bridge and culvert openings. Erosion and Stability Riprap Erosion can occur along the bottom of the slope during high water. Slope erosion is identified by the loss of vegetation and, in more severe areas, scour of the bank. Replacing suitable soil in the eroded area can repair surface failures. Riprap slope protection can be placed on the bank to prevent further erosion in these areas. For large erosion areas, contact DEP for technical assistance and immediate inspection. Riprap must be uniform in size with no large voids. The area at the bottom of the slope must be stable, with complete coverage and no missing stones. If stones become displaced, lost or begin to deteriorate, they should be promptly replaced with stones of uniform size and thickness. Following spring runoff and each major water event, trash and debris should be removed from the riprap. Encroachment No encroachments of any kind are permitted along improved channels or easement areas

33 Buildings and sheds may not be located within or upon the easement areas that would impede the maintenance or inspection of the channel. Grass clippings, lawn and tree trimmings, trash, debris, sediment or other obstructions must be removed before the next high water event. Unwanted Growth Cover All unwanted growth must be removed to provide for access and adequate inspection, and to ensure the channel s waterway capacity. The function of good grass cover is to develop a healthy sod that will protect the slope from scour and erosion. Closure Structures Closure structures are provided where it is necessary to leave an opening in a floodwall or levee for a road, railroad, pedestrian crossing or a bridge approach. Closure structures may be sandbags, aluminum stop logs or fabricated panels. When flood stages are expected, the closures must be erected. Sandbags/Sand An adequate supply of sand and bags are required during flood fight operations and during the erecting of closures. Materials shall be located in sheds or covered areas on the protected side of the levee near the closures. The most commonly used bags are woven polypropylene, approximately 26 by 15 inches. This type of bag withstands rodent deterioration while in storage. These bags should be stored out of direct sunlight. Unused bags can be stockpiled for emergency use and will be serviceable for years if kept dry and properly stored. Bags prefilled with sand or earth material will deteriorate quickly. Untreated bags, or any other kind of bags, can be used in emergencies. A sandy soil is most desirable for filling sandbags, but any other available material such as silt, clay, gravel or a mixture of these may be used

34 Sand is a pervious material and additional weight is obtained when sand is wet. Partially filled sacks shape very well and are easy to handle. DEP, PEMA and the U.S. Army Corps of Engineers can provide sandbags. Stop logs/hardware Stop logs, all related hardware and tools for assembling the closure shall be located on the protected side of the levee near the closures or on a trailer for immediate transport to the closure. Aluminum stop logs require no maintenance; however, they should be supported along their entire length so they do not deform over years of storage. Exercises and Drills The project sponsor must conduct regular drills to determine the length of time and the number of persons needed to assemble the closure. When drills are conducted, DEP should be notified as well as the local railroad, PennDOT, local police fire protection and emergency agencies, in order that alternate traffic routes may be planned for emergency vehicles. STOP LOG CLOSURE STRUCTURES DANVILLE

35 ELDRED JOHNSTOWN Manual Pumping Stations An operation and maintenance manual is provided for each pumping station as a guide to permit successful operation of the station. The manual is prepared to aid the operating personnel in understanding the equipment and to set the guidelines for maintenance procedures. Operation Operation of the pumping station involves criteria, constraints and procedures. The criteria section describes the operation of the facility that satisfies the project requirements. The constraints section indicates all conditions that must be considered external to the station so that it can be successfully operated (as in gate opening and closing operations). The procedure section includes detailed operating procedures for each piece of equipment. Equipment operating procedures are provided by equipment manufacturers

36 Maintenance A pumping station maintenance program consists of inspections, standards, a control system and lubrication. Shop drawings are included in the operation and maintenance manual. The success of a maintenance program is dependent on adequate inspections. The inspection assures that the equipment receives proper attention and is ready for use. The extent of preventative maintenance inspections includes adjusting, lubricating, repairing and replacing worn-out or defective parts. A guide for the inspection frequencies and tasks for the various items of equipment is usually obtained from manufacturers recommendations, but may need to be adjusted for a flood control pumping station s infrequent operating conditions. Any change to manufacturers recommendations should be coordinated with the manufacturer to avoid the possibility of voiding warranties. PUMPING STATIONS DANVILLE DANVILLE DIESEL ENGINE GEAR DRIVE AND PUMP EVERETT PUMP INTAKE GLENSIDE

37 Standards Standards for a balanced criteria maintenance program must be based on defined criteria that establish quality, extent and quantity of maintenance desired. A quality program requires capable personnel, proper tools, use of quality materials and a record of meeting program performance. The maintenance recommendations of most equipment manufacturers are usually for continuous operation, and are typically not the case for flood control pumping stations. Inspection and maintenance requirements must be keyed to the expected operation of the station. Control System An effective maintenance control system should include comprehensive and accurate basic data, such as equipment records, historical inspection, maintenance and repair records. An equipment database file should be provided that indexes equipment by name or title and contains all pertinent data for that equipment, such as manufacturers instruction books, operating pressure limits, parts catalogs, manufacturers drawings, reference field tests, special reports on major requirements, dates of replacements and retirements and, most importantly, changes in operating procedures. A preventive maintenance database file should contain equipment inspection, maintenance data, hours of operation, number of operations and other significant operating data. Lubrication Lubrication is an important part of a good maintenance program. Dependable operation and the life expectancy of equipment requiring lubrication are almost entirely dependent on the use of proper lubricants at the right time intervals and in the proper quantities. Some manufacturers recommend only the viscosity of the lubricant, while others list the lubricants by trade name. The manufacturer will recommend the frequency of lubrication used, but this may have to be adjusted based on special use or experience

38 Exercises Since flood control pumping stations are usually operated on an infrequent basis, trial operation is required between flood events. All equipment should be operated at least every 30 days. It may be acceptable to operate the pumping equipment in the dry providing that the equipment is designed for dry operation and the water level present is below the bottom of the pump suction bell. Wet testing of pumping equipment should occur only if the water present is above the minimum pumping level. These test operations should be included in the maintenance schedule. The duration of the exercise period should be coordinated with the equipment suppliers but should be limited to as short a period as possible. Dams Earthen embankments and concrete structures at debris basins or for detention of flood waters that are part of flood protection projects may be permitted as a dam and must be inspected, operated and maintained according to the rules and regulations of DEP s Division of Dam Safety under Chapter 105 of the Pennsylvania Code on Dam Safety and Waterway Management. The sponsor must inspect dams at least once every three months. Annual inspections of dams, a part of flood protection projects, are conducted by DEP s Division of Project Inspection. The Division of Project Inspection submits an annual report on the condition of the dam each year to DEP s Division of Dam Safety, certified by a registered professional engineer. More frequent reports may be required to assure adequate protection of life and property. A regular maintenance program is required for the successful performance of a dam. Routine maintenance is defined as minor maintenance. A written permit is required from the Division of Dam Safety for any repairs that involve a substantial portion of the structure. An effective maintenance program requires listing regular maintenance items, scheduling the maintenance and repair work and effectively completing the work. Areas of required maintenance primarily include the embankment and other structures considered part of the facility. Maintenance is recognized as a continual effort. Through establishment of a

39 formal schedule, maintenance items resulting from neglect can be avoided. Required maintenance and methods of repair can be found in this manual under levees, concrete and gates. "The Inspection, Maintenance and Operation of Dams in Pennsylvania" is a publication available from DEP s Division of Dam Safety. Contact the Director, Division of Dam Safety, at to obtain a copy and for any additional information. REQUIREMENTS FOR MAINTAINING YOUR FLOOD PROTECTION PROJECT The following information will assist you when you are working in the channel of the flood protection project. Property Rights All work should be confined to the property limits of the project. You do not have authorization to enter upon private property. Should the need arise, you must execute a temporary easement with the property owner. Preconstruction Requirements You are obligated to comply with all federal, state and local laws, regulations and standards for the maintenance of the project. You must contact and coordinate the time of year that the work is performed with the appropriate Pa. Fish and Boat Commission Regional Office. You must develop, implement and display a current Erosion and Sedimentation Control Plan for the maintenance work, approved by your local county conservation district. Construction Requirements The work authorized is to restore the project to its as-built condition. No work may be performed that will increase the channel width, depth or length of the project

40 Excavation must be accomplished using bucket type equipment, not a bulldozer, when working in a stream. All material removed from the stream channel shall be deposited outside of the project limits on a suitable upland spoil area and stabilized to prevent erosion. All work associated with the operation and maintenance of the project shall be accomplished in accordance with all permits. A maintenance plan shall be developed, and a set of as-built drawings must be available on site that details the intended maintenance work. The use of causeways and cofferdams may be required and are acceptable only if clean rocks or non-erodible materials such as jersey barriers, steel sheathing or portadams are used. These devices must be removed in their entirety following maintenance activities. FLOOD PROTECTION PROJECTS DEFINITIONS AND TERMS These are the definitions and terms used frequently for describing features and characteristics of flood protection projects. Access The approach or entrance and exit to the top of a levee or along a channel as in an access ramp or access road. Alignment The location or arrangement of a reference line locating a structure or feature of the project, often identified as the centerline of the levee or channel. Animal Burrows A hole or tunnel dug in a levee or dam by a small animal such as a groundhog for refuge or living, that causes a weakness in the earthen structure and enhancing the potential for seepage to occur. Boil An upward lifting and eruption in the surface of the ground caused by water escaping under pressure from under a levee, floodwall or dam which can result in soil particles being removed from the foundation in the form of muddy water. Breach An opening or a breakthrough of a levee or dam sometimes caused by rapidly flowing water and erosion or scour of a section of the earth embankment

41 Bureau of Waterways Engineering and Wetlands An organizational level of DEP responsible for the flood protection, dam safety and stream improvements programs. Channel A natural or artificial waterway that periodically or continuously contains moving water. It has a definite bed and banks which confine the water. The deep portion of a river or waterway where the main current flows. Closure Structure A temporary structure installed at an opening in a levee or floodwall during high water. Concrete Surface The outer or top of a layer of the concrete structure as in the bottom of the concrete channel or top of the concrete wall. Conduit A closed channel as in a box culvert or pipe that conveys the discharge of water through a levee or dam. Cover The grass and sod on a levee or dam as in ground cover, or the amount or depth of soil over a concrete structure as in cover over a pipe or culvert. Cracking The opening in the soil or fissure found at the top of a levee or dam caused by earth slopes that are unstable, an indication that the slope is failing or will fail. May also refer to surface damage on concrete structures. Cutoff An impervious soil barrier or concrete wall used to reduce or prevent seepage from passing through the foundation under a levee, retaining wall, floodwall or dam. Dam An artificial earthen or concrete barrier constructed for the purpose of impounding water as a reservoir or controlling the outlet flow from a reservoir as a flood control structure. Debris Basin An impoundment at the upstream end of a flood protection project used to trap floating debris and sediment. DEP A department of the Commonwealth of Pennsylvania responsible, in part, for the flood protection program including the planning, design, construction, construction inspection and an inspection and outreach program for sponsors and their completed projects. Depression A low or sunken area along the top of a levee or dam sometimes caused by poor compaction of the soil and resulting in settlement at the location of a pipe or by loss of soil particles through the joints of a pipe. Drainage Slot A small notch or opening at the top of the wall of a concrete channel to allow for local drainage to enter the channel

42 Drainage Structure A pipe or culvert through a levee with a headwall and wingwalls at the inlet and a headwall and wingwalls at the outlet. A flap gate will be mounted at the outlet and sometimes a sluice gate mounted at the inlet, or a twin-celled drop inlet with grating at the inlet cell and a flap gate in the outlet cell. Drainage structures convey local drainage to the stream/channel. Emergency Action Plan A written process or procedure for a community to follow that prevents loss of life and property damage during high water events that includes the flood warning and operations plan for the flood protection project. Encroachments The act of intruding on lands of the flood protection project by building within the designated rights-of-way of the project or by altering or changing project features without permission from the sponsor or DEP. Energy Dissipator A terminal or end structure at a concrete channel or pipe outlet that reduces the high velocity flood flow to slower exit velocities that match the flow in the existing stream. Erosion The loss or wear of levee or channel slopes and stream/channel bottoms caused by the velocity of flowing water that removes grass/sod and soil leaving a denuded surface or void. Exercises and Drills The act of operating project features such as opening and closing sluice gates at drainage structures, installing closure structures across roads and railroad at levees and floodwalls, mobilizing sandbag teams, closure teams and monitoring teams for drills. Flap gate A hinged cover and frame made of cast iron over the opening of a pipe at the outlet of a drainage structure that automatically prevents the backflow of water from the stream through the pipe when the stream is at flood stage. Flood Protection A structure or work used to separate floodwaters from a protected community. Floodwall A reinforced concrete structure constructed as a wall and footing/slab and used to separate floodwaters from the protected community. Freeboard The vertical distance between the design water level, 100- year flood or flood of record, and the top of the levee, floodwall, channel wall or channel bank. Inlet Channel The upstream ditch, swale or waterway leading to a drainage structure or concrete channel

43 Inlet Structure The entrance waterway to a drainage structure or concrete channel. Joints A formed break in concrete wall and slab sections. Contraction joints are normally spaced at 30 feet and are painted with bituminous paint to prevent bond. Expansion joints are normally spaced at 90 feet and are filled with preformed sponge rubber material. Construction joints have through steel reinforcing bars and are located between separate sections of walls for the convenience of placing concrete. Levee A trapezoidal-shaped rolled earth embankment generally composed of an impervious mixture of clay, silt, sand and gravel. Levees are engineered flood protection structures used to separate floodwaters from the protected community. Obstructions A blockage of a channel, culvert or bridge caused by sediment, debris, trees, trash and other materials that would restrict normal and flood flows by reducing the waterway of the structure. One Hundred Year (100-year) flood The flood magnitude expected to be equaled or exceeded on the average of once in 100 years or the flood magnitude with a 1 percent chance of being exceeded in any given year. Also called the base flood. Outlet Channel The downstream ditch, swale or waterway leading away from the drainage structure or concrete channel. Outlet Structure The exit waterway from a drainage structure or concrete channel. Pipe Lining A pipe placed inside another pipe usually at a drainage structure where a plastic pipe is grouted in place to preserve the barrel of the corrugated metal pipe. Ponding Area A shallow impoundment constructed for the purpose of storing stormwater runoff during a flood. Rate of Rise (or Fall) Change in height of water surface in river, stream or ponding area, typically expressed in feet per hour. Riprap A well-graded stone placed on a channel or levee slope that protects the slope from erosion and scour. Sandbags/Sand Plastic woven bags that are used for building sandbag rings around boils, for closure barriers across roads and railroads and other flood fighting operations. Sand is used to fill the bags. Saturated Areas Soft,-spongy ground areas that may have standing water and are found along the landside toe of the levee, floodwall or

44 dam. Water may bubble or percolate from the area under pressure from flood stages on the stream. Sedimentation Suspended sands and gravels that are deposited along the channel by flowing water. Seepage Water, under pressure from flood stages on the stream, moving through or under the levee, floodwall or dam. Settlement Poor compaction of the soil causing a depression usually observed at the top of a levee, dam or on the landside of a floodwall. Slide/Slough The failure and movement of an earthen slope towards the toe of a channel, levee or dam usually caused by poor soils, compaction or saturated areas. Slope Stability The ability of the slope of a channel, levee or dam to restrict movement and sliding. Sluice Gate A gate, normally kept in the full open position, mounted on an inlet structure on the landside of a drainage structure that opens and closes vertically with the use of a lifting device or gate operator. Sponsor The borough/township/county responsible for acquiring lands, relocating utilities and operating and maintaining the project after construction as defined by agreement with DEP. Stoplogs A barrier constructed of aluminum beams to close off levees at roads and railroads. Toe of Levee The intersection of the constructed slope with the natural ground. Trashrack A structure formed by vertical steel members spaced at regular intervals to trap debris and trees normally at the entrance to a concrete channel. Sloped bars closely spaced at the entrance to the sump of a pumping station to prevent trash and debris from entering the station. Unwanted Growth Brush and trees located on the slopes of a channel or on a levee or dam. Warning Time The time period beginning when the potential for a flood is first recognized, and ending when damage reduction activities and response actions must be completed

45 For more information, contact: Pennsylvania Department of Environmental Protection Bureau of Waterways Engineering and Wetlands Division of Project Inspection P.O. Box Market St. Harrisburg, PA (7:30 a.m. to 4:30 p.m.) For more information, visit DEP s website at keyword: Flood Protection. Commonwealth of Pennsylvania Department of Environmental Protection An Equal Opportunity Employer 3100-BK-DEP2734 Rev. 4/2014