ABBREVIATIONS DIA DIAMETER EL ELEVATION FT2 SQUARE FOOT GAL/MIN GALLONS PER MINUTE H HORIZONTAL HDPE HIGH DENSITY POLYETHYLENE HMAC HOT MIX ASPHALT CONCRETE IE INVERT ELEVATION MAX MAXIMUM NO. NUMBER ODEQ OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY ODOT OREGON DEPARTMENT OF TRANSPORTATION OPT OPTIONAL PE POLYETHYLENE PVC POLYVINYL CHLORIDE S SLOPE TYP TYPICAL UIC UNDERGROUND INJECTION CONTROL V VERTICAL Abbreviations Dwg LID 0.00 1 of 1
LIST OF DETAILS LID 0.00 Abbreviations LID 0.01 List of Details LID 1.00 Flow Chart: Choosing the right rain garden detail LID 1.01 Simple Infiltration Rain Garden LID 1.02 Infiltration Rain Garden LID 1.03 Infiltration Rain Garden with Planting Soil LID 1.04 Lined Filtration Rain Garden LID 1.05 Unlined Filtration Rain Garden LID 2.00 Flow Chart: Choosing the right planter detail LID 2.01 Infiltration Planter LID 2.02 Infiltration Planter with Planting Soil LID 2.03 Lined Filtration Planter LID 2.04 Unlined Filtration Planter LID 3.00 Flow Chart: Choosing the right swale detail LID 3.01 Lined Filtration Swale LID 3.02 Unlined Filtration LID 3.03 Infiltration Swale LID 3.04 Infiltration Swale with Planting Soil LID 4.01 Vegetated Filter Strip for Overland Flow LID 4.02 Vegetated Filter Strips with Planting Soil for Overland Flow LID 4.03 Vegetated Filter Strip with Planting Soil for Concentrated Flow LID 4.04 Vegetated Filter Strip for Overland Flow- Berm Variation LID 5.01 Pervious Concrete Pavement LID 5.02 Porous Asphalt Pavement LID 5.03 Manufactured Permeable Pavers LID 5.04 Salvaged and Poured Concrete Permeable Pavers LID 5.05 Vehicular Permeable Paver Edges LID 6.01 Soakage Trench in Landscaped Area LID 6.02 Soakage Trench Beneath Impervious Pavement LID 6.03 Soakage Trench Beneath Porous Pavement LID 6.04Soakage Trench in Fractured Bedrock LID 7.01 Drywell in Landscaped Area LID 7.02 Drywell in Paved Area LID 8.01 Catch Basin Control Structure LID 8.02 Rocked Lined Conveyance Swale LID 8.03 Vegetated Conveyance Swale LID 8.04 Pretreatment for Sedments from Overland Flow with VFS LID 8.05 Pretreatment for Sediments from Overland Flow with a Rock Edge List of Details LID 0.01 1 of 1
DEPTH TO SEASONAL GROUNDWATER TABLE FROM BOTTOM OF RAIN GARDEN > 3 FEET AND DEPTH TO BEDROCK > 2 FEET Y RAIN GARDEN CAN BE LOCATED A MINIMUM OF 10 FEET AWAY FROM EXISTING OR FUTURE BUILDINGS AND WALLS OR INFILTRATION IN THE PROPOSED LOCATION HAS BEEN APPROVED BY A GEOTECHNICAL ENGINEER. Y INFILTRATION RATE OF NATIVE UNDISTURBED SOILS < 12 INCHES/HR* Y N N N LID 1.04 LINED FILTRATION RAIN GARDEN OVEREXCAVATION TO A SOIL WITH AN ADEQUATE INFILTRATION RATE IS POSSIBLE AND THEN RAIN GARDEN WILL BE SIZED TO DRAIN WITHIN 30 HOURS Y N N LID 1.05 FILTRATION RAIN GARDEN WITHOUT AN IMPERMEABLE LINER RAIN GARDEN SIZED TO DRAIN WITHIN 30 HOURS Y NATIVE SOILS ARE SUITABLE FOR CHOSEN PLANTS Y LID 1.01 OR LID 1.02 INFILTRATION RAIN GARDEN N LID 1.03 INFILTRATION RAIN GARDEN WITH PLANTING SOIL Flow Chart: Choosing the Right Rain Garden Detail These details are provided for you to use and modify as desired. Use at your own risk. Dwg LID 1.00
3H:1V SIDE SLOPES MAX, TYP WIDTH (5' MIN) 6"-12" TYP PONDING DEPTH NATIVE PLANTS PER LANDSCAPE ARCHITECT/DESIGNER BERM AS NEEDED COMPACTED STRUCTURAL FILL EXISTING GRADE 2-3" MULCH UNDISTURBED NATIVE SUBGRADE INFILTRATION RAIN GARDEN NOTES DESIGN NOTES: 1. PLANT WITH PLANTS PER LANDSCAPE ARCHITECT DWGS. NATIVE PLANTS ARE PREFERRED, BECAUSE NON-NATIVE AND INVASIVE SPECIES CAN REPRODUCE DOWNSTREAM TO DAMAGE HABITAT AND CHANGE HYDROLOGY. IF NON-NATIVES ARE CHOSEN, BE SURE THAT THEY WILL NOT DAMAGE DOWNSTREAM WATERWAYS. CONSTRUCTION NOTES: 2. BUILD AND VEGETATE RAIN GARDEN AS EARLY AS POSSIBLE TO ESTABLISH PLANTINGS BEFORE DIRECTING STORMWATER RUNOFF TO IT OR DIVERT STORMWATER AROUND FACILITY. PREFERABLY, THIS PERIOD WOULD LAST A MINIMUM OF 3 MONTHS OR PER LANDSCAPE ARCHITECT/DESIGNER GUIDELINES. 3. INFILTRATION AREAS (THE AREA OF THE RAIN GARDEN AS DEFINED BY THE TOP ELEVATION OF THE FACILITY) SHALL BE FENCED OFF FROM THE FIRST DAY OF EARTH MOVING UNTIL PROJECT COMPLETION TO PREVENT COMPACTION OF THE SUBGRADE, DIRT TRACKING ONTO ANY LAYER OF THE FACILITY, AND STOCKPILING OF CONSTRUCTION MATERIALS THAT MAY CLOG THE SURFACE. 4. DURING EXCAVATION OF NATIVE SOILS TO THE BOTTOM OF THE FACILITY, RAINFALL MAY CAUSE FINES TO CLOG THE SURFACE OF THE FACILITY. IF THIS OCCURS DURING CONSTRUCTION, HAND RAKE THE SURFACE TO A DEPTH OF 3" TO RESTORE INFILTRATION CAPACITY. 5. CALL THE CIVIL ENGINEER, [ENTER NAME HERE] AT [ENTER PHONE NUMBER HERE] 24 HOURS IN ADVANCE OF CONSTRUCTING THIS FACILITY SO CONSTRUCTION OBSERVATION MAY BE PERFORMED TO IDENTIFY VARIATIONS IN THE FIELD THAT MAY AFFECT DESIGN AND VERIFY PROPER CONSTRUCTION. Simple Infiltration Rain Garden LID 1.01 1 of 1
3H:1V SIDE SLOPES MAX, TYP SEE NOTE 4 6"-12" TYP PONDING DEPTH SEE NOTE 6 WIDTH (5' MIN) SEE NOTE 7 NATIVE PLANTS PER LANDSCAPE ARCHITECT/DESIGER SEE NOTE 3 BERM AS NEEDED SEE NOTE 2 COMPACTED STRUCTURAL FILL SEE NOTE 5 EXISTING GRADE SEE NOTE 5 2-3" MULCH SEE NOTE 3 & 8 UNDISTURBED NATIVE SUBGRADE SEE NOTE 5 THESE NOTES IN RED ARE OFFERED AS A GUIDE FOR DECISION MAKING WHEN YOU WANT TO CHANGE THIS DETAIL. 1. INFILTRATION RATE OF NATIVE SOILS: INFILTRATION RAIN GARDEN DETAIL MAY BE USED WHEN NATIVE SOILS HAVE AN INFILTRATION RATE THAT DOES NOT EXCEED 12 INCHES/HOUR AND WHEN OVERLAND FLOW FROM THE FACILITY DURING LARGE STORMS CAN BE SAFELY CONVEYED AWAY FROM BUILDINGS AND WALLS WITHOUT A CATCH BASIN AND PIPE. 2. LARGE STORM OVERFLOW: AT THE LOW POINT OF THE PROPOSED GRADES, THE BERM HEIGHT SHOULD BE A LITTLE LOWER THAN THE REST OF THE BERM SO THAT EXCESS RUNOFF FROM LARGE STORMS FLOWS IN THE DESIRED DIRECTION. THIS BERM SHOULD ALSO BE REINFORCED WITH SOME RIP RAP OR EXTRA PLANTS THAT WILL PREVENT EROSION WHEN FLOWS PASS OVER IT. 3. VEGETATION: THE MORE PLANTS THE BETTER AND THE BIGGER THE BETTER. WHERE TREES AND SHRUBS CAN BE SAFELY (IE VISIBILITY CONSIDERATIONS) PLANTED IN THE BASIN, THEY SHOULD BE. CONSIDER HYDROSEEDING WITH GRASS SPECIES SIMILAR TO THE SPECIES THAT WILL LIKELY BE PLANTED AS PLUGS TO STABILIZE SOILS FOR THE LONG-TERM AND AVOID THE PROBLEMS WITH FLOATING MULCH, OR USE ROCK MULCH. 4. SIDE SLOPES: DON'T ALLOW A MAXIMUM SLOPE OF GREATER THAN 3H:1V. PLANT ESTABLISHMENT IS DIFFICULT ABOVE THIS SLOPE BECAUSE SLOPES EXCEEDING THIS MUST BE COMPACTED.COMPACTION OF THE SIDE SLOPES REDUCES THE INFILTRATION CAPACITY OF THE FACILITY. 5. THE IMPORTANCE OF CUT AND FILL FOR INFILTRATION FACILITIES: THE BOTTOM OF AN INFILTRATION RAIN GARDEN MUST BE IN CUT IN NATIVE SOILS. FILL REQUIRES COMPACTION, WHICH CREATES SOIL DENSITIES AND RUNOFF PATTERNS SIMILAR TO IMPERVIOUS SURFACES SUCH AS CONCRETE. ONE RULE OF THUMB, IS THAT INFILTRATION FACILITIES MAY BE PLACED IN FILL AREAS THAT ARE OVER 5 YEARS OLD SINCE THESE SOILS WILL HAVE BEEN LOOSENED BY SOIL ANIMALS AND VEGETATION OVER TIME. 6. APPROPRIATE VOLUMES: RIM ELEVATION SHOULD BE SET SO THAT, AT A MINIMUM, THE VOLUME OF THE WATER QUALITY STORM IS RETAINED ON-SITE. DEPENDING ON THE CONDITIONS IN YOUR JURISDICTION (AVAILABILITY, AND CAPACITY OF EXISTING STORM SEWERS, RAINFALL DISTRIBUTIONS AND GOALS FOR WATERSHED PROTECTION,) A LARGER VOLUME MAY AND IS PROBABLY APPROPRIATE TO RETAIN ON-SITE. TO CHOOSE THE RIGHT VOLUME FOR CAPACITY OF THE RAIN GARDEN, MODEL/ACCOUNT FOR THE VOLUME OF RUNOFF THAT'S INFILTRATING DURING THE STORM, THE STORAGE CAPACITY OF THE FACILITY, THE RIM ELEVATION, AND THE VOLUME LEFTOVER AT THE END OF THE STORM. 7. THE WIDTH OF THE FACILITY EQUALS THE PONDING AREA AND THE INILTRATION AREA AS LONG AS SIDE SLOPES DON'T EXCEED 3:1. 8. BARK MULCH FLOATS AND WILL FLOAT RIGHT OUT OF THE FACILITY, SO DON'T USE IT. USE COURSE WOOD CHIPS OR ROCK MULCH INSTEAD. Simple Infiltration Rain Garden SEE NOTE 1 These details are provided for you to use and modify as desired. Use at your own risk. LID 1.01.ai 1 of 1
6"-12" TYP PONDING DEPTH 3H:1V SIDE SLOPES MAX, TYP RIM EL=XXX.XX WIDTH (5' MIN) BEEHIVE RIM NATIVE PLANTS PER LANDSCAPE ARCHITECT/DESIGNER BERM AS NEEDED COMPACTED STRUCTURAL FILL EXISTING GRADE 2-3" MULCH IE OUT = XXX.XX 18" UNDISTURBED NATIVE SUBGRADE AREA DRAIN NON-PERFORATED OVERFLOW PIPE MIN SUMP DEPTH 3" 3 4"-0 DRAIN ROCK, OPT. COMPACTED NATIVE SUBGRADE INFILTRATION RAIN GARDEN NOTES DESIGN NOTES: 1. PLANT WITH PLANTS PER LANDSCAPE ARCHITECT DWGS. NATIVE PLANTS ARE PREFERRED, BECAUSE NON-NATIVE AND INVASIVE SPECIES CAN REPRODUCE DOWNSTREAM AND DAMAGE HABITAT. IF NON-NATIVES ARE CHOSEN, BE SURE THAT THEY WILL NOT DAMAGE DOWNSTREAM HABITAT. CONSTRUCTION NOTES: 2. BUILD AND VEGETATE RAIN GARDEN AS EARLY AS POSSIBLE TO ESTABLISH PLANTINGS BEFORE DIRECTING STORMWATER RUNOFF TO IT, OR DIVERT STORMWATER AROUND FACILITY. PREFERABLY, THIS PERIOD WOULD LAST A MINIMUM OF 3 MONTHS OR PER LANDSCAPE ARCHITECT/DESIGNER GUIDELINES. 3. INFILTRATION AREAS (THE AREA OF THE RAIN GARDEN AS DEFINED BY THE TOP ELEVATION OF THE FACILITY) SHALL BE FENCED OFF FROM THE FIRST DAY OF EARTH MOVING UNTIL PROJECT COMPLETION TO PREVENT COMPACTION OF THE SUBGRADE, DIRT TRACKING ONTO ANY LAYER OF THE FACILITY AND STOCKPILING OF CONSTRUCTION MATERIALS THAT MAY CLOG THE SURFACE. 4. DURING EXCAVATION OF NATIVE SOILS TO THE BOTTOM OF THE FACILITY, RAINFALL MAY CAUSE FINES TO CLOG THE SURFACE OF THE FACILITY. IF THE NATIVE SOIL HAS BEEN EXPOSED TO RAINFALL, HAND RAKE THE SURFACE TO A DEPTH OF 3" TO RESTORE INFILTRATION CAPACITY. 6. CALL THE CIVIL ENGINEER, [ENTER NAME HERE] AT [ENTER PHONE NUMBER HERE] 24 HOURS IN ADVANCE OF CONSTRUCTING THIS FACILITY SO CONSTRUCTION OBSERVATION MAY BE PERFORMED TO IDENTIFY VARIATIONS IN THE FIELD THAT MAY AFFECT DESIGN AND VERIFY PROPER CONSTRUCTION. 7. DURING AREA DRAIN INSTALLATION, DISTURB NATIVE SOILS AS LITTLE AS POSSIBLE. Infiltration Rain Garden LID 1.02 1 of 1
6"-12" TYP PONDING DEPTH SEE NOTE 6 3H:1V SIDE SLOPES MAX, TYP SEE NOTE 4 RIM EL=XXX.XX SEE NOTE 6 WIDTH (5' MIN) SEE NOTE 9 BEEHIVE RIM SEE NOTE 7 NATIVE PLANTS PER LANDSCAPE ARCHITECT/DESIGNER SEE NOTE 3 BERM AS NEEDED COMPACTED STRUCTURAL FILL SEE NOTE 5 EXISTING GRADE SEE NOTE 5 IE OUT = XXX.XX 2-3" MULCH SEE NOTE 10 UNDISTURBED NATIVE SUBGRADE SEE NOTE 5 AREA DRAIN SEE NOTE 2 NON-PERFORATED OVERFLOW PIPE SEE NOTE 8 MIN SUMP DEPTH 3" 3 4"-0 DRAIN ROCK, OPT. COMPACTED NATIVE SUBGRADE THESE NOTES IN RED ARE OFFERED AS A GUIDE FOR DECISION MAKING WHEN YOU WANT TO MAKE CHANGES TO THIS DETAIL. 1. INFILTRATION RATE OF NATIVE SOILS: INFILTRATION RAIN GARDEN DETAIL MAY BE USED WHEN NATIVE SOILS HAVE AN INFILTRATION RATE THAT DOES NOT EXCEED 12 INCHES/HOUR. 2. LARGE STORM OVERFLOW: AN AREA DRAIN OR OTHER STRUCTURAL OVERFLOW MAY NOT BE NEEDED WHERE OVERLAND FLOWS OVER A SIMPLE BERM WILL CONVEY LARGE VOLUME FLOWS SAFELY OVERLAND AWAY FROM STRUCTURES AND TOWARDS AN ALTERNATIVE CONVEYANCE SYSTEM. 3. VEGETATION: THE MORE PLANTS THE BETTER AND THE BIGGER THE BETTER. WHERE TREES AND SHRUBS CAN BE SAFELY (IE VISIBILITY CONSIDERATIONS) PLANTED IN THE BASIN, THEY SHOULD BE. FOR EROSION CONTROL, CONSIDER HYDROSEEDING WITH GRASS SPECIES SIMILAR TO THE SPECIES THAT WILL LIKELY BE PLANTED AS PLUGS TO STABILIZE SOILS FOR THE LONG-TERM. 4. SIDE SLOPES: DON'T EXCEED A SLOPE OF 3H:1V. PLANT ESTABLISHMENT IS DIFFICULT ABOVE THIS SLOPE BECAUSE SLOPES EXCEEDING THIS MUST BE COMPACTED. SIDE SLOPE COMPACTION REDUCES THE INFILTRATION CAPACITY OF THE FACILITY. 5. THE IMPORTANCE OF CUT AND FILL FOR INFILTRATION FACILITIES: THE BOTTOM OF AN INFILTRATION RAIN GARDEN MUST BE IN CUT IN NATIVE SOILS. FILL REQUIRES COMPACTION, WHICH INCREASES SOIL DENSITY AND GENERATES RUNOFF PATTERNS SIMILAR TO IMPERVIOUS SURFACES SUCH AS CONCRETE. ONE RULE OF THUMB IS THAT INFILTRATION FACILITIES MAY BE PLACED IN FILL AREAS THAT ARE OVER 5 YEARS OLD SINCE THESE SOILS WILL HAVE BE LOOSENED BY SOIL ANIMALS AND VEGETATION OVER TIME. 6. APPROPRIATE VOLUMES: RIM ELEVATION SHOULD BE SET SO THAT, AT A MINIMUM, THE VOLUME OF THE WATER QUALITY STORM IS RETAINED ON-SITE. DEPENDING ON THE CONDITIONS IN YOUR JURISDICTION (AVAILABILITY, AND CAPACITY OF EXISTING STORM SEWERS, RAINFALL DISTRIBUTIONS AND GOALS FOR WATERSHED PROTECTION,) A LARGER VOLUME MAY AND IS PROBABLY APPROPRIATE TO RETAIN ON-SITE. TO CHOOSE THE RIGHT VOLUME FOR CAPACITY OF THE RAIN GARDEN, MODEL/ACCOUNT FOR THE VOLUME OF RUNOFF THAT'S INFILTRATING DURING THE STORM (REQUIRES AN INFILTRATION TEST), THE STORAGE CAPACITY OF THE FACILITY, THE RIM ELEVATION, AND THE VOLUME LEFTOVER AT THE END OF THE STORM.A BEEHIVE RIM IS RECOMMENDED BECAUSE IT'S LESS LIKELY TO GET CLOGGED WITH LEAVES AND TRASH. OTHER OUTLETS (DITCH INLET, PLUMBING BENDS PER CITY OF PORTLAND OVERFLOW STRUCTURE,ETC) COULD BE FINE, BUT WE SUGGEST AVOIDING A FLAT RIM. 7. SIZE THIS PIPE TO CONVEY THE 25-YEAR PEAK FLOW AFTER ATTENUATION FROM THE RAIN GARDEN. 8. THE WIDTH OF THE FACILITY EQUALS THE PONDING AREA AND THE INFILTRATION AREA AS LONG AS THE SIDES SLOPES DON'T EXCEED 3H:1V.. 9. BARK MULCH FLOATS AND WILL FLOAT RIGHT OUT OF THE FACILITY, SO DON'T USE IT. USE COURSE WOOD CHIPS OR ROCK MULCH INSTEAD. Infiltration Rain Garden SEE NOTE 1 These details are provided for you to use and modify as desired. Use at your own risk. LID 1.02.ai 1 of 1
6"-12" TYP PONDING DEPTH 3H:1V SIDE SLOPES, TYP RIM EL=XXX.XX WIDTH (5' MIN) BEEHIVE RIM NATIVE PLANTS PER LANDSCAPE ARCHITECT/DESIGER BERM AS NEEDED COMPACTED STRUCTURAL FILL EXISTING GRADE 18" AMENDED PLANTING SOIL MIN SUMP DEPTH IE OUT = XXX.XX COMPACTED NATIVE SUBGRADE 18" AREA DRAIN 3" 3 4"-0 DRAIN ROCK, OPT. 2-3" MULCH EXCAVATE AT STABLE SLOPE ANGLE FOR NATIVE SOIL NON-PERFORATED OVERFLOW PIPE TO APPROVED DISPOSAL POINT INFILTRATION RAIN GARDEN WITH PLANTING SOIL NOTES DESIGN NOTES: 1. PLANT WITH PLANTS PER LANDSCAPE ARCHITECT DWGS. NATIVE PLANTS ARE PREFERRED, BECAUSE NON-NATIVE AND INVASIVE SPECIES CAN MOVE DOWNSTREAM AND DAMAGE HABITAT. IF NON-NATIVES ARE CHOSEN, BE SURE THAT THEY WILL NOT DAMAGE DOWNSTREAM HABITAT. CONSTRUCTION NOTES: 2. BUILD AND VEGETATE RAIN GARDEN AS EARLY AS POSSIBLE TO ESTABLISH PLANTINGS BEFORE DIRECTING STORMWATER RUNOFF TO IT OR DIVERT STORMWATER AROUND FACILITY. PREFERABLY, THIS PERIOD WOULD LAST A MINIMUM OF 3 MONTHS OR PER LANDSCAPE ARCHITECT/DESIGNER GUIDELINES. 3. INFILTRATION AREAS (THE AREA OF THE RAIN GARDEN AS DEFINED BY THE TOP ELEVATION OF THE FACILITY) SHALL BE FENCED OFF FROM THE FIRST DAY OF EARTH MOVING UNTIL PROJECT COMPLETION TO PREVENT COMPACTION OF THE SUBGRADE, DIRT TRACKING ONTO ANY LAYER OF THE FACILITY AND STOCKPILING OF CONSTRUCTION MATERIALS THAT MAY CLOG THE SURFACE. 4. DURING EXCAVATION OF NATIVE SOILS TO THE BOTTOM OF THE FACILITY, RAINFALL MAY CAUSE FINES TO CLOG THE SURFACE OF THE FACILITY. IF THE NATIVE SOIL HAS BEEN EXPOSED TO RAINFALL, HAND RAKE THE SURFACE TO A DEPTH OF 3" TO RESTORE INFILTRATION CAPACITY. 5. CALL THE CIVIL ENGINEER, [ENTER NAME HERE] AT [ENTER PHONE NUMBER HERE] 24 HOURS IN ADVANCE OF CONSTRUCTING THIS FACILITY SO CONSTRUCTION OBSERVATION MAY BE PERFORMED TO IDENTIFY VARIATIONS IN THE FIELD THAT MAY AFFECT DESIGN AND VERIFY PROPER CONSTRUCTION. 6. DURING AREA DRAIN INSTALLATION, DISTURB NATIVE SOILS AS LITTLE AS POSSIBLE. Infiltration Rain Garden With Planting Soil LID 1.03 1 of 2
AMENDED PLANTING SOIL MIX SPECIFICATIONS 1. AMENDED PLANTING SOIL MIX SHALL HAVE THE FOLLOWING CHARACTERISTICS: a. 60% LOAMY SAND AND 40% COMPOST. b. ORGANIC CONTENT MATTER FROM 8-10% BY WEIGHT c. CATION EXCHANGE CAPACITY (CEC) GREATER THAN OR EQUAL TO 5 MILLIEQUIVALENTS/100 GRAMS OF DRY SOIL d. 2-5% MINERAL FINES CONTENT e. US STANDARD PERCENT SIEVE SIZE PASSING 3 8" 100 #4 95-100 #10 75-90 #40 25-40 #100 4-10 #200 2-5 f. MINIMUM LONG-TERM HYDRAULIC CONDUCTIVITY OF 1 INCH/HOUR PER ASTM D2434 AT 85% COMPACTION PER ASTM D 1557. g. MAXIMUM IMMEDIATE HYDRAULIC CONDUCTIVITY OF 12 INCHES/HOUR. 2. AMENDED PLANTING SOIL MIX MAY BE CREATED BY TESTING ON-SITE NATIVE SOILS AND MIXING MATERIALS FROM OFF-SITE AS NEEDED TO ACHIEVE THE CHARACTERISTICS DESCRIBED IN NOTE 1 ABOVE. 3. AMENDED PLANTING SOIL MIX SHOULD BE UNIFORMLY MIXED WITH A SOIL MIXER. 4. PLACEMENT OF AMENDED PLANTING SOIL MIX SHALL OCCUR PER THE FOLLOWING GUIDELINES: a. PLACE SOIL IN 12" LIFTS, KEEPING MACHINERY OUTSIDE OF INFILTRATION AREA. b. DO NOT PLACE SOILS IF SATURATED. c. COMPACT EACH LIFT WITH WATER OR BOOT PACKING UNTIL JUST SATURATED TO 85% COMPACTION. DO NOT COMPACT WITH HEAVY MACHINERY OR VIBRATORY COMPACTION. Infiltration Rain Garden With Planting Soil LID 1.03 1 of 2
6"-12" TYP PONDING DEPTH SEE NOTE 6 3H:1V SIDE SLOPES, TYP SEE NOTE 4 RIM EL=XXX.XX SEE NOTE 6 WIDTH (5' MIN) SEE NOTE 10 BEEHIVE RIM SEE NOTE 7 & 12 NATIVE PLANTS PER LANDSCAPE ARCHITECT/DESIGNER SEE NOTE 3 BERM AS NEEDED COMPACTED STRUCTURAL FILL SEE NOTE 5 EXISTING GRADE SEE NOTE 5 EXCAVATE AT STABLE SLOPE ANGLE FOR NATIVE SOIL 2-3" MULCH SEE NOTE 11 IE OUT = XXX.XX AMENDED PLANTING SOIL SEE NOTE 9 AREA DRAIN SEE NOTE 2 NON-PERFORATED OVERFLOW PIPE SEE NOTE 8 MIN SUMP DEPTH 3" 3 4"-0 DRAIN ROCK, OPT. COMPACTED NATIVE SUBGRADE THESE NOTES IN RED ARE OFFERED AS A GUIDE FOR DECISION MAKING WHEN YOU WANT TO CHANGE THIS DETAIL: 1. INFILTRATION RATE OF NATIVE SOILS: USE INFILTRATION RAIN GARDEN WITH PLANTING SOIL DETAIL WHEN NATIVE SOILS HAVE AN INFILTRATION RATE THAT EXCEEDS 12 INCHES/HOUR OR EXISTING NATIVE SOILS ARE UNDESIRABLE FOR GROWING PLANTS. 2. LARGE STORM OVERFLOW: A CATCH BASIN OR OTHER STRUCTURAL OVERFLOW MAY NOT BE NEEDED WHERE OVERLAND FLOWS OVER A SIMPLE BERM WILL CONVEY LARGE VOLUME FLOWS SAFELY OVERLAND AWAY FROM STRUCTURES AND TOWARDS AN ALTERNATIVE CONVEYANCE SYSTEM. 3. VEGETATION: THE MORE PLANTS THE BETTER AND THE BIGGER THE BETTER. WHERE TREES AND SHRUBS CAN BE SAFELY (IE VISIBILITY CONSIDERATIONS) PLANTED IN THE BASIN, THEY SHOULD BE. FOR EROSION CONTROL, CONSIDER HYDROSEEDING WITH GRASS SPECIES SIMILAR TO THE SPECIES THAT WILL LIKELY BE PLANTED AS PLUGS TO STABILIZE SOILS FOR THE LONG-TERM. 4. SIDE SLOPES: DON'T EXCEED A SLOPE OF 3H:1V. PLANT ESTABLISHMENT IS DIFFICULT ABOVE THIS SLOPE BECAUSE SLOPES EXCEEDING THIS MUST BE COMPACTED..THIS ALSO REDUCES THE EFFECTIVE INFILTRATION AREA OF THE FACILITY. 5. THE IMPORTANCE OF CUT AND FILL FOR INFILTRATION FACILITIES: THE BOTTOM OF AN INFILTRATION RAIN GARDEN MUST BE IN CUT IN NATIVE SOILS. FILL REQUIRES COMPACTION, WHICH INCREASES SOIL DENSITY AND GENERATES RUNOFF PATTERNS SIMILAR TO IMPERVIOUS SURFACES SUCH AS CONCRETE. ONE RULE OF THUMB, THOUGH, IS THAT INFILTRATION FACILITIES MAY BE PLACED IN FILL AREAS THAT ARE OVER 5 YEARS OLD SINCE THESE SOILS WILL HAVE BE LOOSENED BY SOIL ANIMALS AND VEGETATION OVER TIME.. 6. APPROPRIATE VOLUMES: RIM ELEVATION SHOULD BE SET SO THAT, AT A MINIMUM, THE VOLUME OF THE WATER QUALITY STORM IS RETAINED ON-SITE. DEPENDING ON THE CONDITIONS IN YOUR JURISDICTION (AVAILABILITY, AND CAPACITY OF EXISTING STORM SEWERS, RAINFALL DISTRIBUTIONS AND GOALS FOR WATERSHED PROTECTION,) A LARGER VOLUME MAY AND IS PROBABLY APPROPRIATE TO RETAIN ON-SITE. TO CHOOSE THE RIGHT VOLUME FOR CAPACITY OF THE RAIN GARDEN, MODEL/ACCOUNT FOR THE VOLUME OF RUNOFF THAT'S INFILTRATING DURING THE STORM (REQUIRES AN INFILTRATION TEST), THE STORAGE CAPACITY OF THE FACILITY, THE RIM ELEVATION, AND THE VOLUME LEFTOVER AT THE END OF THE STORM. 7. A BEEHIVE RIM IS RECOMMENDED BECAUSE IT'S LESS LIKELY TO GET CLOGGED WITH LEAVES AND TRASH. OTHER OUTLETS (DITCH INLET, PLUMBING BENDS PER CITY OF PORTLAND OVERFLOW STRUCTURE,ETC) COULD BE FINE, BUT WE SUGGEST AVOIDING A FLAT RIM. 8. SIZE THIS PIPE TO CONVEY THE 25-YEAR PEAK FLOW AFTER ATTENUATION FROM THE RAIN GARDEN. 9. THIS GUIDANCE HAS BEEN ADAPTED FROM A TECHNICAL MEMORANDUM ISSUED IN JANUARY 2009 BY THE WASHINGTON STATE UNIVERSITY ON BIORETENTION SOIL MIX: "Bioretention Soil Mix Recommendations for Western Washington" found online at http://www.psparchives.com/publications/our_work/stormwater/bsmresults-guidelines%20final.pdf. IN A PHONE CONVERSATION WITH THE MAIN AUTHOR, CHRIS HINMAN, THESE SOILS ARE CONSIDERED TO BE GOOD FOR ANY REGION, NOT JUST WESTERN WASHINGTON, AS THE TITLE MIGHT IMPLY. 18" IS THE MINIMUM DEPTH NEEDED TO PROVIDE ADEQUATE WATER QUALITY. 10. THE WIDTH OF THE FACILITY EQUALS THE PONDING AREA AND THE INFILTRATION AREA AS LONG AS SIDE SLOPES DON'T EXCEED 3H:1V. 11. B.ARK MULCH FLOATS AND WILL FLOAT RIGHT OUT OF THE FACILITY, SO DON'T USE IT. USE COURSE WOOD CHIPS OR ROCK MULCH INSTEAD. 12. DON'T USE METALS SINCE THEY WILL EITHER RUST ADDING IRON TO YOUR DOWNSTREAM OR WON'T RUST (GALVANIZED) AND ADD ZINC TO YOUR DOWNSTREAM. Infiltration Rain Garden With Planting Soil SEE NOTE 1 LID 1.03 1 of 2
NATIVE PLANTS PER LANDSCAPE ARCHITECT/DESIGER 2-3" MULCH BERM AS NEEDED BEEHIVE RIM 6"-12" TYP PONDING DEPTH INSTALL LINER ABOVE RIM EL 3H:1V SIDE SLOPES MAX, TYP COMPACTED STRUCTURAL FILL RIM EL=XXX.XX WIDTH (5' MIN) WOOD STAKE EXISTING GRADE 2" 18" MIN 3" 3" 12" SEPERATION/FILTER ROCK LAYER EXCAVATE AT STABLE SLOPE ANGLE FOR NATIVE SOIL IE OUT = XXX.XX 18" 1 2 "- 3 8" CRUSHED GRAVEL IMPERMEABLE LINER MIN SUMP DEPTH COARSE SAND AMENDED PLANTING SOIL AREA DRAIN 6" PERFORATED HDPE PIPE, S=0.0000 UNIFORMLY GRADED STORAGE ROCK NON-PERFORATED OVERFLOW PIPE DIRECTED TO APPROVED DISPOSAL POINT UNDISTURBED NATIVE SUBGRADE 3" 3 4"-0 DRAIN ROCK, OPT COMPACTED NATIVE SUBGRADE Lined Filtration Rain Garden LID 1.04 1 of 3
FILTRATION RAIN GARDEN NOTES DESIGN NOTES: 1. PLANT WITH PLANTS PER LANDSCAPE ARCHITECT DWGS. NATIVE PLANTS ARE PREFERRED, BECAUSE NON-NATIVE AND INVASIVE SPECIES CAN MOVE DOWNSTREAM AND DAMAGE HABITAT. IF NON-NATIVES ARE CHOSEN, BE SURE THAT THEY WILL NOT DAMAGE DOWNSTREAM HABITAT. 2. IMPERMEABLE LINER MAY BE 30 MIL PE OR PVC POND LINER OR BENTONITE CLAY MAT. CONSTRUCTION NOTES: 3. BUILD AND VEGETATE RAIN GARDEN AS EARLY AS POSSIBLE TO ESTABLISH PLANTINGS BEFORE DIRECTING STORMWATER RUNOFF TO IT OR DIVERT STORMWATER AROUND FACILITY. PREFERABLY, THIS PERIOD WOULD LAST A MINIMUM OF 3 MONTHS. 4. INFILTRATION AREAS (THE AREA OF THE RAIN GARDEN AS DEFINED BY THE TOP ELEVATION OF THE FACILITY) SHALL BE FENCED OFF FROM THE FIRST DAY OF EARTH MOVING UNTIL PROJECT COMPLETION TO PREVENT COMPACTION OF THE SUBGRADE, DIRT TRACKING ONTO ANY LAYER OF THE FACILITY AND STOCKPILING OF CONSTRUCTION MATERIALS THAT MAY CLOG THE SURFACE. 5. DURING EXCAVATION OF NATIVE SOILS TO THE BOTTOM OF THE FACILITY, RAINFALL MAY CAUSE FINES TO CLOG THE SURFACE OF THE FACILITY.IF THE NATIVE SOIL HAS BEEN EXPOSED TO RAINFALL, HAND RAKE THE SURFACE TO A DEPTH OF 3" TO RESTORE INFILTRATION CAPACITY. 6. CALL THE CIVIL ENGINEER, [ENTER NAME HERE] AT [ENTER PHONE NUMBER HERE] 24 HOURS IN ADVANCE OF CONSTRUCTING THIS FACILITY SO VARIATIONS IN THE FIELD CAN BE IDENTIFIED BY CONSTRUCTION OBSERVATION. 7. DURING AREA DRAIN INSTALLATION, DISTURB NATIVE SOILS AS LITTLE AS POSSIBLE. 8. DO NOT PUNCTURE LINER ANYWHERE EXCEPT AT THE TOP AS SHOWN. IF AN ALTERNATE LINER CONFIGURATION IS USED, ENSURE THAT DURING EVERY STORM FOR EVERY DEPTH OF WATER THAT MAY BE RETAINED, THE LINER PROTECTS STRUCTURES FROM WATER DAMAGE. AMENDED PLANTING SOIL MIX SPECIFICATIONS 1. AMENDED PLANTING SOIL MIX SHALL HAVE THE FOLLOWING CHARACTERISTICS: a. 60% LOAMY SAND AND 40% COMPOST. b. ORGANIC CONTENT MATTER FROM 8-10% BY WEIGHT c. CATION EXCHANGE CAPACITY (CEC) GREATER THAN OR EQUAL TO 5 MILLIEQUIVALENTS/100 GRAMS OF DRY SOIL d. 2-5% MINERAL FINES CONTENT e. US STANDARD PERCENT SIEVE SIZE PASSING 3 8" 100 #4 95-100 #10 75-90 #40 25-40 #100 4-10 #200 2-5 f. MINIMUM LONG-TERM HYDRAULIC CONDUCTIVITY OF 1 INCH/HOUR PER ASTM D2434 AT 85% COMPACTION PER ASTM D 1557. g. MAXIMUM IMMEDIATE HYDRAULIC CONDUCTIVITY OF 12 INCHES/HOUR. 2. AMENDED PLANTING SOIL MIX MAY BE CREATED BY TESTING ON-SITE NATIVE SOILS AND MIXING MATERIALS FROM OFF-SITE AS NEEDED TO MEET THE SPECIFICATIONS IN NOTE 1 ABOVE. 3. AMENDED PLANTING SOIL MIX SHOULD BE UNIFORMLY MIXED WITH A SOIL MIXER. 4. PLACEMENT OF AMENDED PLANTING SOIL MIX SHALL OCCUR PER THE FOLLOWING GUIDELINES: a. PLACE SOIL IN 12" LIFTS, KEEPING MACHINERY OUTSIDE OF INFILTRATION AREA. b. DO NOT PLACE SOILS IF SATURATED. c. COMPACT EACH LIFT WITH WATER OR BOOT PACKING UNTIL JUST SATURATED TO 85% COMPACTION. DO NOT COMPACT WITH HEAVY MACHINERY OR VIBRATORY COMPACTION. Lined Filtration Rain Garden LID 1.04 2 of 3
SEPARATION/FILTER ROCK SPECIFICATIONS 1. SEPARATION/FILTER ROCK SHALL BE WASHED ROCK. 2. THE COARSE SAND PORTION SHALL MEET HAVE THE FOLLOWING GRADATION: US. STANDARD PERCENT SIEVE SIZE PASSING 3 8" 100 #4 54-82 #10 34-56 #40 9-17 #100 0-3 3. THE 2"- 1 3 8" CRUSHED GRAVEL PORTION SHALL MEET THE FOLLOWING GRADATION (ASTM C-33): US. STANDARD PERCENT SIEVE SIZE PASSING 1 2" 100 3 8" 85-100 #4 10-30 #10 0-10 #8 0-10 #16 0-5 4. UNIFORMLY GRADED STORAGE ROCK SHALL MEET THE FOLLOWING GRADATION: US. STANDARD PERCENT SIEVE SIZE PASSING 12" 1 100 1" 95-100 1 2" 25-60 #4 0-10 #8 0-5 5. UNIFORMLY GRADED STORAGE ROCK SHALL HAVE A MINIMUM VOID RATIO OF 30%. Lined Filtration Rain Garden LID 1.04 3 of 3
WOOD STAKE 6"-12" TYP PONDING DEPTH SEE NOTE 6 3H:1V SIDE SLOPES MAX, TYP SEE NOTE 4 RIM EL=XXX.XX SEE NOTE 6 WIDTH (5' MIN) 2-3" MULCH SEE NOTE 15 BEEHIVE RIM SEE NOTE 7 & 14 NATIVE PLANTS PER LANDSCAPE ARCHITECT/DESIGNER SEE NOTE 3 BERM AS NEEDED 2" INSTALL LINER ABOVE RIM EL COMPACTED STRUCTURAL FILL SEE NOTE 5 EXISTING GRADE SEE NOTE 5 SEE NOTE 10 SEPERATION/FILTER ROCK LAYER 1 2 "-3 8 " CRUSHED GRAVEL COARSE SAND 3" 3" 12" 18" MIN IE OUT = XXX.XX 18" EXCAVATE AT STABLE SLOPE ANGLE FOR NATIVE SOIL IMPERMEABLE LINER SEE NOTE 13 AMENDED PLANTING SOIL SEE NOTE 11 AREA DRAIN SEE NOTE 2 NON-PERFORATED OVERFLOW PIPE DIRECTED TO APPROVED DISPOSAL POINT SEE NOTE 8 MIN SUMP DEPTH UNIFORMLY GRADED STORAGE ROCK UNDISTURBED NATIVE SUBGRADE 3" 3 4 "-0 DRAIN ROCK, OPT COMPACTED NATIVE SUBGRADE 6" PERFORATED HDPE PIPE, S=0.0000 THESE NOTES IN RED ARE OFFERED AS A GUIDE FOR DECISION MAKING WHEN YOU WANT TO MAKE CHANGES TO THIS DETAIL. 1. INFILTRATION RATE OF NATIVE SOILS: DOESN'T AFFECT THE DESIGN OF THIS FACILITY. FACILITIES THAT DON'T INFILTRATE MAY PROTECT WATER QUALITY AT THE SITE WHERE THEY RECEIVE RUNOFF, BUT IMPACT WATER QUALITY AND HABITAT VALUE THROUGH EROSIVE FLOWS IN DOWNSTREAM WATERWAYS. THIS FACILITY SHOULD ONLY BE USED WHEN SITE PLANNING WILL NOT ALLOW A FACILITY TO BE PLACED AT LEAST 10' FROM A BUILDING OR SITE WALL OR WHEN NATURAL CONDITIONS ARE THAT A HIGH GROUNDWATER TABLE IS WITHIN 3' OF THE BOTTOM OF THE FACILITY OR WHEN BEDROCK OR OTHER INFILTRATION BARRIER IS WITHIN 2' OF THE BOTTOM OF THE FACILITY. 2. LARGE STORM OVERFLOW: AN AREA DRAIN OR OTHER STRUCTURAL OVERFLOW MAY NOT BE NEEDED WHERE OVERLAND FLOWS OVER A SIMPLE BERM WILL CONVEY LARGE VOLUME FLOWS SAFELY OVERLAND AWAY FROM STRUCTURES AND TOWARDS AN ALTERNATIVE CONVEYANCE SYSTEM. 3. VEGETATION: THE MORE PLANTS THE BETTER AND THE BIGGER THE BETTER. WHERE TREES AND SHRUBS CAN BE SAFELY (IE VISIBILITY CONSIDERATIONS) PLANTED IN THE BASIN, THEY SHOULD BE. FOR EROSION CONTROL, CONSIDER HYDROSEEDING WITH GRASS SPECIES SIMILAR TO THE SPECIES THAT WILL LIKELY BE PLANTED AS PLUGS TO STABILIZE SOILS FOR THE LONG-TERM. 4. SIDE SLOPES: DON'T EXCEED A SLOPE OF 3H:1V. PLANT ESTABLISHMENT IS DIFFICULT ABOVE THIS SLOPE BECAUSE SLOPES EXCEEDING THIS MUST BE COMPACTED..THIS ALSO REDUCES THE EFFECTIVE INFILTRATION AREA OF THE FACILITY. 5. THE IMPORTANCE OF CUT AND FILL FOR LINED FILTRATION FACILITIES: SINCE WE'RE ONLY TREATING STORMWATER AND NOT INFILTRATING,THE BOTTOM OF AN INFILTRATION RAIN GARDEN CAN BE LOCATED IN CUT OR FILL. 6. APPROPRIATE VOLUMES: RIM ELEVATION SHOULD BE SET SO THAT THE VOLUME OF THE WATER QUALITY STORM FLOWS THROUGH THE AMENDED PLANTING SOIL. 7. A BEEHIVE RIM IS RECOMMENDED BECAUSE IT'S LESS LIKELY TO GET CLOGGED WITH LEAVES AND TRASH. OTHER OUTLETS (DITCH INLET, PLUMBING BENDS PER CITY OF PORTLAND OVERFLOW STRUCTURE,ETC) COULD BE FINE, BUT WE SUGGEST AVOIDING A FLAT RIM. 8. SIZE THIS PIPE TO CONVEY THE 25-YEAR PEAK FLOW AFTER ATTENUATION FROM THE RAIN GARDEN. 9. TAKEN FROM ODOT MATERIAL SPECIFICATIONS FOR SPECIAL FILTER MATERIAL FOR BACKFILLING TRENCHES WITH PERFORATED DRAINS, SECTION 02610. 10. IN THE PAST A GEOTEXTILE WAS USED TO SEPARATE THE PLANTING SOIL FROM THE STORAGE ROCK BELOW (TO PRESERVE STORAGE IN THE ROCK VOIDS); HOWEVER, BOTH PRIVATE DESIGNERS AND PUBLIC AGENCIES HAVE FOUND THAT A GEOTEXTILE USED IN THIS APPLICATION IS VERY LIKELY TO CLOG. WHILE THIS ROCK SUBSTITUTE IS THE LATEST THINKING TO PROVIDE SEPARATION, IT HAS BEEN USED SUCCESSFULLY AT THE UNIVERSITY OF NEW HAMPSHIRE STORMWATER CENTER AND IS CONSIDERED THE BEST ALTERNATIVE. MODIFYING THIS DETAIL TO USE A GEOTEXTILE INSTEAD OF THE PEA GRAVEL AND COARSE SAND LAYER MAY NOT BE VERY SUCCESSFUL, UNLESS YOU VERIFY THAT THE PLANTING SOIL MIX YOU'RE SPECIFYING WILL NOT CLOG THE GEOTEXTILE. DETAILING OF THESE TWO LAYERS WAS ADAPTED FROM A UNH GUIDANCE DOCUMENT ON BIORETENTION (RAIN GARDEN) FACILITIES AT http://www.unh.edu/erg/cstev/fact_sheets/bio_ii_fact_sheet_08.pdf 11. THIS GUIDANCE HAS BEEN ADAPTED FROM A TECHNICAL MEMORANDUM ISSUED IN JANUARY 2009 BY THE WASHINGTON STATE UNIVERSITY ON BIORETENTION SOIL MIX: "Bioretention Soil Mix Recommendations for Western Washington" found online at http://www.psparchives.com/publications/our_work/stormwater/bsmresults-guidelines%20final.pdf. IN A PHONE CONVERSATION WITH THE MAIN AUTHOR, CHRIS HINMAN, THESE SOILS ARE CONSIDERED TO BE GOOD FOR ANY REGION, NOT JUST WESTERN WASHINGTON, AS THE TITLE MIGHT IMPLY. 18" IS THE MINIMUM DEPTH NEEDED TO PROVIDE ADEQUATE WATER QUALITY. 12. THE VOID RATIO OF ALL OPEN GRADED ROCK, REGARDLESS OF SIZE, RANGES FROM 30-40%. 13. WHERE THE LINER IS NEEDED BECAUSE OF INADEQUATE SETBACKS TO BUILDING FOUNDATIONS, WALLS, OR OTHER INFRASTRUCTURE THAT MIGHT BE DAMAGED, THE LINER MUST BE DESIGNED TO COME UP TO AT LEAST THE MAXIMUM PONDING ELEVATION. IN THIS EXAMPLE, THE BERM ON THE LOW SIDE IS HOLDING WATER IN BUT IT'S ASSUMED THAT THIS WILL SERVE AS THE LARGE STORM (100-YEAR) OVERFLOW AND THAT NO INFRASTRUCTURE IS DOWNHILL THAT MIGHT BE DAMAGED BY THESE FLOWS (OTHERWISE, THE RAIN GARDEN SHOULD BE PLACED SOMEWHERE ELSE). THE UPPER SIDE IS ASSUMED TO HAVE SOMETHING THAT NEEDS TO BE PROTECTED AND THE LINER ON THIS SIDE SHOULD COME UP TO THE MAXIMUM WATER LEVEL. ANOTHER CONSIDERATION IS HOW MUCH SOIL WILL BE ABLE TO BE PLACED OVER THE LINER TO SUPPORT PLANTS. GRASSES NEED 12" MIN, SHRUBS NEED 18" MIN AND TREES NEED 36" MIN. FOR SUSTAINABILITY REASONS, CHOOSE BENTONITE CLAY MAT, THEN PE. AVOID PVC LINERS BECAUSE OF THE DAMAGE TO THE LARGER ENVIRONMENT IN THEIR PRODUCTION 14. DON'T USE METALS SINCE THEY WILL EITHER RUST ADDING IRON TO YOUR DOWNSTREAM OR WON'T RUST (GALVANIZED) AND ADD ZINC TO YOUR DOWNSTREAM. 15. BARK MULCH FLOATS AND WILL FLOAT RIGHT OUT OF THE FACILITY, SO DON'T USE IT. USE COURSE WOOD CHIPS OR ROCK MULCH INSTEAD Lined Filtration Rain Garden SEE NOTE 1 LID 1.04.ai 1 of 1
NATIVE PLANTS PER LANDSCAPE ARCHITECT/DESIGER 2-3" MULCH BERM AS NEEDED BEEHIVE RIM 6"-12" TYP PONDING DEPTH INSTALL LINER ABOVE RIM EL 3H:1V SIDE SLOPES MAX, TYP COMPACTED STRUCTURAL FILL RIM EL=XXX.XX 2" WIDTH (5' MIN) EXISTING GRADE 18" MIN 3" 3" 3" 3" 12" SEPERATION/FILTER ROCK LAYER EXCAVATE AT STABLE SLOPE ANGLE FOR NATIVE SOIL 18" IE OUT = XXX.XX IMPERMEABLE LINER AMENDED PLANTING SOIL 6" PERFORATED HDPE PIPE, S=0.0000 AREA DRAIN MIN SUMP DEPTH UNIFORMLY GRADED STORAGE ROCK NON-PERFORATED OVERFLOW PIPE DIRECTED TO APPROVED DISPOSAL POINT 1 2 "- 3 8" CRUSHED GRAVEL UNDISTURBED NATIVE SUBGRADE COARSE SAND 3" 3 4"-0 DRAIN ROCK, OPT COMPACTED NATIVE SUBGRADE Unlined Filtration Rain Garden LID 1.05 1 of 3
FILTRATION RAIN GARDEN NOTES DESIGN NOTES: 1. PLANT WITH PLANTS PER LANDSCAPE ARCHITECT DWGS. NATIVE PLANTS ARE PREFERRED, BECAUSE NON-NATIVE AND INVASIVE SPECIES CAN MOVE DOWNSTREAM AND DAMAGE HABITAT. IF NON-NATIVES ARE CHOSEN, BE SURE THAT THEY WILL NOT DAMAGE DOWNSTREAM HABITAT. CONSTRUCTION NOTES: 2. BUILD AND VEGETATE RAIN GARDEN AS EARLY AS POSSIBLE TO ESTABLISH PLANTINGS BEFORE DIRECTING STORMWATER RUNOFF TO IT OR DIVERT STORMWATER AROUND FACILITY. PREFERABLY, THIS PERIOD WOULD LAST A MINIMUM OF 3 MONTHS. 3. INFILTRATION AREAS (THE AREA OF THE RAIN GARDEN AS DEFINED BY THE TOP ELEVATION OF THE FACILITY) SHALL BE FENCED OFF FROM THE FIRST DAY OF EARTH MOVING UNTIL PROJECT COMPLETION TO PREVENT COMPACTION OF THE SUBGRADE, DIRT TRACKING ONTO ANY LAYER OF THE FACILITY AND STOCKPILING OF CONSTRUCTION MATERIALS THAT MAY CLOG THE SURFACE. 4. DURING EXCAVATION OF NATIVE SOILS TO THE BOTTOM OF THE FACILITY, RAINFALL MAY CAUSE FINES TO CLOG THE SURFACE OF THE FACILITY. IF THE NATIVE SOIL HAS BEEN EXPOSED TO RAINFALL, HAND RAKE THE SURFACE TO A DEPTH OF 3" TO RESTORE INFILTRATION CAPACITY. 5. CALL THE CIVIL ENGINEER, [ENTER NAME HERE] AT [ENTER PHONE NUMBER HERE] 24 HOURS IN ADVANCE OF CONSTRUCTING THIS FACILITY SO VARIATIONS IN THE FIELD CAN BE IDENTIFIED BY CONSTRUCTION INSPECTION. 6. DURING AREA DRAIN INSTALLATION, DISTURB NATIVE SOILS AS LITTLE AS POSSIBLE. AMENDED PLANTING SOIL MIX SPECIFICATIONS 1. AMENDED PLANTING SOIL MIX SHALL HAVE THE FOLLOWING CHARACTERISTICS: a. 60% LOAMY SAND AND 40% COMPOST. b. ORGANIC CONTENT MATTER FROM 8-10% BY WEIGHT c. CATION EXCHANGE CAPACITY (CEC) GREATER THAN OR EQUAL TO 5 MILLIEQUIVALENTS/100 GRAMS OF DRY SOIL d. 2-5% MINERAL FINES CONTENT e. US STANDARD PERCENT SIEVE SIZE PASSING 3 8" 100 #4 95-100 #10 75-90 #40 25-40 #100 4-10 #200 2-5 f. MINIMUM LONG-TERM HYDRAULIC CONDUCTIVITY OF 1 INCH/HOUR PER ASTM D2434 AT 85% COMPACTION PER ASTM D 1557. g. MAXIMUM IMMEDIATE HYDRAULIC CONDUCTIVITY OF 12 INCHES/HOUR. 2. AMENDED PLANTING SOIL MIX MAY BE CREATED BY TESTING ON-SITE NATIVE SOILS AND MIXING MATERIALS FROM OFF-SITE AS NEEDED TO ACHIEVE THE CHARACTERISTICS DESCRIBED IN NOTE 1 ABOVE. 3. AMENDED PLANTING SOIL MIX SHOULD BE UNIFORMLY MIXED WITH A SOIL MIXER. 4. PLACEMENT OF AMENDED PLANTING SOIL MIX SHALL OCCUR PER THE FOLLOWING GUIDELINES: a. PLACE SOIL IN 12" LIFTS TO A DEPTH OF 24" TOTAL (AFTER COMPACTION) WITH MACHINERY ADJACENT STORMWATER QUALITY FACILITY. b. DO NOT PLACE SOILS IF SATURATED. c. COMPACT TO 85% COMPACTION WITH WATER LIFTS UNTIL SATURATED. DO NOT COMPACT WITH HEAVY MACHINERY OR WITH VIBRATORY COMPACTION. BOOT PACKING THE LIFTS IS ACCEPTABLE. Unlined Filtration Rain Garden LID 1.05 2 of 3
SEPERATION/FILTER ROCK SPECIFICATIONS 1. SEPERATION/FILTER ROCK SHALL BE WASHED ROCK. 2. THE COARSE SAND PORTION SHALL MEET HAVE THE FOLLOWING GRADATION: US. STANDARD PERCENT SIEVE SIZE PASSING 3 8" 100 #4 54-82 #10 34-56 #40 9-17 #100 0-3 3. THE 2"- 1 3 8" CRUSHED GRAVEL PORTION SHALL MEET THE FOLLOWING GRADATION (ASTM C-33): US. STANDARD PERCENT SIEVE SIZE PASSING 1 2" 100 3 8" 85-100 #4 10-30 #10 0-10 #8 0-10 #16 0-5 4. UNIFORMLY GRADED STORAGE ROCK SHALL MEET THE FOLLOWING GRADATION: US. STANDARD PERCENT SIEVE SIZE PASSING 12" 1 100 1" 95-100 1 2" 25-60 #4 0-10 #8 0-5 5. UNIFORMLY GRADED STORAGE ROCK SHALL HAVE A MINIMUM VOID RATIO OF 30%. Unlined Filtration Rain Garden LID 1.05 3 of 3
6"-12" TYP PONDING DEPTH SEE NOTE 6 3H:1V SIDE SLOPES MAX, TYP SEE NOTE 4 RIM EL=XXX.XX SEE NOTE 6 WIDTH (5' MIN) 2-3" MULCH SEE NOTE 13 BEEHIVE RIM SEE NOTE 7 & 14 NATIVE PLANTS PER LANDSCAPE ARCHITECT/DESIGNER SEE NOTE 3 BERM AS NEEDED 2" INSTALL LINER ABOVE RIM EL COMPACTED STRUCTURAL FILL SEE NOTE 5 EXISTING GRADE SEE NOTE 5 SEPERATION/FILTER SEE NOTE 10 ROCK LAYER UNIFORMLY GRADED STORAGE ROCK SEE NOTE 13 UNDISTURBED NATIVE SUBGRADE 3" 3" 12" 18" 3" MIN 3" IE OUT = XXX.XX 1 2"- 3 8 " CRUSHED GRAVEL COARSE SAND EXCAVATE STABLE SLOPE ANGLE OF NATIVE SOIL AREA DRAIN SEE NOTE 2 AMENDED PLANTING SOIL SEE NOTE 11 THESE NOTES IN RED ARE OFFERED AS A GUIDE FOR DECISION MAKING WHEN YOU WANT TO MAKE CHANGES TO THIS DETAIL. 1. INFILTRATION RATE OF NATIVE SOILS: DOESN'T AFFECT THE DESIGN OF THIS FACILITY. THE IDEA BEHIND GETTING RID OF THE LINER IS TO ELIMINATE AN ACTUAL COST TO THE OWNER IN MATERIAL AND INSTALLATION, TO MINIMIZE THE AMOUNT OF UNNECESSARY PLASTIC THAT'S BEING USED ON THE PROJECT AND TO ALLOW AT LEAST A LITTLE BIT OF INFILTRATION IF POSSIBLE, BUT IT WOULD BE EXPECTED THAT THIS WOULDN'T BE SIGNIFICANT ENOUGH TO CREDIT WITH STORMWATER VOLUME DISPOSAL. 2. LARGE STORM OVERFLOW: AN AREA DRAIN OR OTHER STRUCTURAL OVERFLOW MAY NOT BE NEEDED WHERE OVERLAND FLOWS OVER A SIMPLE BERM WILL CONVEY LARGE VOLUME FLOWS SAFELY OVERLAND AWAY FROM STRUCTURES AND TOWARDS AN ALTERNATIVE CONVEYANCE SYSTEM. 3. VEGETATION: THE MORE PLANTS THE BETTER AND THE BIGGER THE BETTER. WHERE TREES AND SHRUBS CAN BE SAFELY (IE VISIBILITY CONSIDERATIONS) PLANTED IN THE BASIN, THEY SHOULD BE. FOR EROSION CONTROL, CONSIDER HYDROSEEDING WITH GRASS SPECIES SIMILAR TO THE SPECIES THAT WILL LIKELY BE PLANTED AS PLUGS TO STABILIZE SOILS FOR THE LONG-TERM. 4. SIDE SLOPES: DON'T EXCEED A SLOPE OF 3H:1V. PLANT ESTABLISHMENT IS DIFFICULT ABOVE THIS SLOPE BECAUSE SLOPES EXCEEDING THIS MUST BE COMPACTED.THIS ALSO REDUCES THE EFFECTIVE INFILTRATION AREA OF THE FACILITY. 5. THE IMPORTANCE OF CUT AND FILL FOR INFILTRATION FACILITIES: THE BOTTOM OF AN INFILTRATION RAIN GARDEN MUST BE IN CUT IN NATIVE SOILS. FILL REQUIRES COMPACTION, WHICH INCREASES SOIL DENSITY AND GENERATES RUNOFF PATTERNS SIMILAR TO IMPERVIOUS SURFACES SUCH AS CONCRETE. ONE RULE OF THUMB, THOUGH, IS THAT INFILTRATION FACILITIES MAY BE PLACED IN FILL AREAS THAT ARE OVER 5 YEARS OLD SINCE THESE SOILS WILL HAVE BE LOOSENED BY SOIL ANIMALS AND VEGETATION OVER TIME.. 6. APPROPRIATE VOLUMES: RIM ELEVATION SHOULD BE SET SO THAT, AT A MINIMUM, THE VOLUME OF THE WATER QUALITY STORM IS RETAINED ON-SITE. A LARGER VOLUME MAY AND IS PROBABLY APPROPRIATE TO RETAIN ON-SITE, DEPENDING ON THE CONDITIONS IN YOUR JURISDICTION (AVAILABILITY, AND CAPACITY OF EXISTING STORM SEWERS, RAINFALL DISTRIBUTIONS AND GOALS FOR WATERSHED PROTECTION). TO CHOOSE THE RIGHT VOLUME FOR CAPACITY OF THE RAIN GARDEN, MODEL/ACCOUNT FOR THE VOLUME OF RUNOFF THAT'S INFILTRATING DURING THE STORM (REQUIRES AN INFILTRATION TEST), THE STORAGE CAPACITY OF THE FACILITY, THE RIM ELEVATION, AND THE VOLUME LEFTOVER AT THE END OF THE STORM. 7. A BEEHIVE RIM IS RECOMMENDED BECAUSE IT'S LESS LIKELY TO GET CLOGGED WITH LEAVES AND TRASH. OTHER OUTLETS (DITCH INLET, PLUMBING BENDS PER CITY OF PORTLAND OVERFLOW STRUCTURE,E ETC) COULD BE FINE, BUT WE SUGGEST AVOIDING A FLAT RIM. 8. SIZE THIS PIPE TO CONVEY THE 25-YEAR PEAK FLOW AFTER ATTENUATION BY THE RAIN GARDEN. 9. TAKEN FROM ODOT MATERIAL SPECIFICATIONS FOR SPECIAL FILTER MATERIAL FOR BACKFILLING TRENCHES WITH PERFORATED DRAINS, SECTION 02610. 10. IN THE PAST A GEOTEXTILE WAS USED TO SEPARATE THE PLANTING SOIL FROM THE STORAGE ROCK BELOW (TO PRESERVE STORAGE IN THE ROCK VOIDS); HOWEVER, BOTH PRIVATE DESIGNERS AND PUBLIC AGENCIES HAVE FOUND THAT A GEOTEXTILE USED IN THIS APPLICATION IS VERY LIKELY TO CLOG. WHILE THIS ROCK SUBSTITUTE IS THE LATEST THINKING TO PROVIDE SEPARATION, IT HAS BEEN USED SUCCESSFULLY AT THE UNIVERSITY OF NEW HAMPSHIRE STORMWATER CENTER AND IS CONSIDERED THE BEST ALTERNATIVE. MODIFYING THIS DETAIL TO USE A GEOTEXTILE INSTEAD OF THE PEA GRAVEL AND COARSE SAND LAYER MAY NOT BE VERY SUCCESSFUL, UNLESS YOU VERIFY THAT THE PLANTING SOIL MIX YOU'RE SPECIFYING WILL NOT CLOG THE GEOTEXTILE. DETAILING OF THESE TWO LAYERS WAS ADAPTED FROM A UNH GUIDANCE DOCUMENT ON BIORETENTION (RAIN GARDEN) FACILITIES AT http://www.unh.edu/erg/cstev/fact_sheets/bio_ii_fact_sheet_08.pdf 11. THIS GUIDANCE HAS BEEN ADAPTED FROM A TECHNICAL MEMORANDUM ISSUED IN JANUARY 2009 BY THE WASHINGTON STATE UNIVERSITY ON BIORETENTION SOIL MIX: "Bioretention Soil Mix Recommendations for Western Washington" found online at http://www.psparchives.com/publications/our_work/stormwater/bsmresults-guidelines%20final.pdf. IN A PHONE CONVERSATION WITH THE MAIN AUTHOR, CHRIS HINMAN, THESE SOILS ARE CONSIDERED TO BE GOOD FOR ANY REGION, NOT JUST WESTERN WASHINGTON, AS THE TITLE MIGHT IMPLY. 18" IS THE MINIMUM DEPTH NEEDED TO PROVIDE ADEQUATE WATER QUALITY. ANOTHER CONSIDERATION IS HOW MUCH SOIL WILL BE ABLE TO BE PLACED OVER THE ROCK LAYERS TO SUPPORT PLANTS. GRASSES NEED 12" MIN, SHRUBS NEED 18" MIN AND TREES NEED 36" MIN. 12. THE VOID RATIO OF ALL OPEN GRADED ROCK, REGARDLESS OF SIZE, TENDS TO RANGE FROM 30-40%. 13. BARK MULCH FLOATS AND WILL FLOAT RIGHT OUT OF THE FACILITY, SO DON'T USE IT. USE COURSE WOOD CHIPS OR ROCK MULCH INSTEAD. 14. DON'T USE METALS SINCE THEY WILL EITHER RUST ADDING IRON TO YOUR DOWNSTREAM OR WON'T RUST (GALVANIZED) AND ADD ZINC TO YOUR DOWNSTREAM. 18" NON-PERFORATED OVERFLOW PIPE SEE NOTE 8 MIN SUMP DEPTH 3" 3 4 "-0 DRAIN ROCK, OPT COMPACTED NATIVE SUBGRADE 6" PERFORATED HDPE PIPE, S=0.0000 NON-WOVEN GEOTEXTILE SEPARATION ON SIDES, PARTIAL HEIGHT, OVERLAP 12" MIN Unlined Filtration Rain Garden SEE NOTE 1 LID 1.05.ai 1 of 1
DEPTH TO SEASONAL GROUNDWATER TABLE FROM BOTTOM OF RAIN GARDEN > 3 FEET AND DEPTH TO BEDROCK > 2 FEET Y SWALE CAN BE LOCATED A MINIMUM OF 10 FEET AWAY FROM EXISTING OR FUTURE BUILDINGS AND WALLS OR INFILTRATION IN THE PROPOSED LOCATION HAS BEEN APPROVED BY A GEOTECHNICAL ENGINEER. Y FACILITY IS BEING USED AS PRE-TREATMENT IN CONJUNCTION WITH OTHER LID FACILITIES THAT AREN'T UICS OR A HIGH LEVEL OF WATER QUALITY TREATMENT IS YNOT REQUIRED N N Y N LID 2.03 LINED FILTRATION PLANTER LID 2.04 FILTRATION PLANTER WITHOUT AN IMPERMEABLE LINER SWALE HAS CHECK DAMS AND STORED WATER WILL DRAIN WITHIN 30 HOURS Y INFILTRATION RATE OF NATIVE UNDISTURBED SOILS < 12 INCHES/HR* N Y NATIVE SOILS ARE SUITABLE FOR CHOSEN PLANTS Y N N LID 2.01 INFILTRATION PLANTER OVEREXCAVATION TO A SOIL WITH AN ADEQUATE INFILTRATION RATE IS POSSIBLE AND THEN RAIN GARDEN WILL BE SIZED TO DRAIN WITHIN 30 HOURS N LID 2.02 INFILTRATION PLANTER WITH PLANTING SOIL Y N INFILTRATION RATE OF NATIVE UNDISTURBED SOILS > 12 INCHES/HR Flow Chart: Choosing the Swale Detail Dwg LID 3.00
6"-12" TYP PONDING DEPTH RIM EL=XXX.XX WIDTH (18" MIN) BEEHIVE RIM NATIVE PLANTS PER LANDSCAPE ARCHITECT/DESIGER DEEP CURB OR WALL, CONSULT GEOTECHNICAL ENGINEER FOR OVERTURNING ANALYSIS FINISH GRADE APPROVED FILL, OPT EXISTING GRADE 2-3" MULCH IE OUT = XXX.XX 18" 3" 3 4"-0 DRAIN ROCK, OPT. DISTURBED NATIVE SUBGRADE AREA DRAIN NON-PERFORATED OVERFLOW PIPE TO APPROVED DISCHARGE POINT MIN SUMP DEPTH COMPACTED NATIVE SUBGRADE UNDISTURBED NATIVE SUBGRADE INFILTRATION PLANTER NOTES DESIGN NOTES: 1. PLANT WITH PLANTS PER LANDSCAPE ARCHITECT DWGS. NATIVE PLANTS ARE PREFERRED, BECAUSE NON-NATIVE AND INVASIVE SPECIES CAN MOVE DOWNSTREAM AND DAMAGE HABITAT. IF NON-NATIVES ARE CHOSEN, BE SURE THAT THEY WILL NOT DAMAGE DOWNSTREAM HABITAT. CONSTRUCTION NOTES: 2. BUILD AND VEGETATE PLANTERS AS EARLY AS POSSIBLE TO ESTABLISH PLANTINGS BEFORE DIRECTING STORMWATER RUNOFF TO IT OR DIVERT STORMWATER AROUND FACILITY. PREFERABLY, THIS PERIOD WOULD LAST A MINIMUM OF 3 MONTHS. 3. INFILTRATION AREAS (THE AREA OF THE PLANTER AS DEFINED BY THE TOP ELEVATION OF THE DEEP CURBS OR WALLS) SHALL BE FENCED OFF FROM THE FIRST DAY OF EARTH MOVING UNTIL PROJECT COMPLETION TO PREVENT COMPACTION OF THE SUBGRADE, DIRT TRACKING ONTO ANY LAYER OF THE FACILITY AND STOCKPILING OF CONSTRUCTION MATERIALS THAT MAY CLOG THE SURFACE. 4. DURING EXCAVATION OF NATIVE SOILS TO THE BOTTOM OF THE FACILITY, RAINFALL MAY CAUSE FINES TO CLOG THE SURFACE OF THE FACILITY. IF THE NATIVE SOIL HAS BEEN EXPOSED TO RAINFALL, HAND RAKE THE SURFACE TO A DEPTH OF 3" TO RESTORE INFILTRATION CAPACITY. 5. CALL THE CIVIL ENGINEER, [ENTER NAME HERE] AT [ENTER PHONE NUMBER HERE] 24 HOURS IN ADVANCE OF CONSTRUCTING THIS FACILITY SO VARIATIONS IN THE FIELD CAN BE IDENTIFIED BY CONSTRUCTION INSPECTION. 6. DURING AREA DRAIN INSTALLATION, DISTURB NATIVE SOILS AS LITTLE AS POSSIBLE. Infiltration Planter LID 2.01 1 of 1
6"-12" TYP PONDING DEPTH SEE NOTE 6 THESE NOTES IN RED ARE OFFERED AS A GUIDE FOR DECISION MAKING WHEN YOU WANT TO MAKE CHANGES TO THIS DETAIL. 1. INFILTRATION RATE OF NATIVE SOILS: INFILTRATION PLANTER DETAIL MAY BE USED WHEN NATIVE SOILS HAVE AN INFILTRATION RATE THAT DOES NOT EXCEED 12 INCHES/HOUR. GENERALLY, YOU'D ONLY INCUR THE EXTRA COST OF AN INFILTRATION PLANTER OVER AN INFILTRATION RAIN GARDEN IF YOUR SPACE FOR INFILTRATION IS CONSTRICTED AND YOU NEED THE ADDITIONAL RUNOFF STORAGE THAT YOU GET FROM VERTICAL WALLS. 2. LARGE STORM OVERFLOW: A CATCH BASIN OR OTHER STRUCTURAL OVERFLOW MAY NOT BE NEEDED WHERE OVERLAND FLOWS OVER THE TOP OF THE FACILITY WILL CONVEY LARGE VOLUME FLOWS SAFELY OVERLAND AWAY FROM STRUCTURES AND TOWARDS AN ALTERNATIVE CONVEYANCE SYSTEM. 3. VEGETATION: THE MORE PLANTS THE BETTER AND THE BIGGER THE BETTER. WHERE TREES AND SHRUBS CAN BE SAFELY (IE VISIBILITY CONSIDERATIONS) PLANTED IN THE BASIN, THEY SHOULD BE. CONSIDER HYDROSEEDING WITH GRASS SPECIES SIMILAR TO THE SPECIES THAT WILL LIKELY BE PLANTED AS PLUGS TO STABILIZE SOILS FOR THE LONG-TERM AND AVOID THE PROBLEMS WITH FLOATING MULCH. 4. DEEP CURBS OR WALL: THESE MATERIALS SHOULD BE NON-POLLUTING MATERIALS, DEFINITELY NOT METAL. IF YOU'RE WATERPROOFING, BE CAREFUL WITH THAT MATERIAL CHOICE, TOO. FOR A MORE COST EFFECTIVE PLANTER, THIS CAN ALSO JUST BE A REGULAR 16" DEEP CURB WITH AN UNTREATED WOOD FRAME THE REST OF THE WAY TO THE BOTTOM TO HOLD THE NATIVE SOILS BACK DURING CONSTRUCTION OF THE FACILITY. THE WOOD WILL ROT BUT IS ONLY NEEDED DURING CONSTRUCTION ANYWAY. SALVAGED CONCRETE CURBS ARE ALSO A GOO D ALTERNATIVE. WALLS CAN BE BATTERED IF NEEDED. 5. THE IMPORTANCE OF CUT AND FILL FOR INFILTRATION FACILITIES: THE BOTTOM OF AN INFILTRATION PLANTER MUST BE IN CUT IN NATIVE SOILS. FILL REQUIRES COMPACTION, WHICH INCREASES SOIL DENSITY AND GENERATES RUNOFF PATTERNS SIMILAR TO IMPERVIOUS SURFACES SUCH AS CONCRETE. ONE RULE OF THUMB, THOUGH, IS THAT INFILTRATION FACILITIES MAY BE PLACED IN FILL AREAS THAT ARE OVER 5 YEARS OLD SINCE THESE SOILS WILL HAVE BE LOOSENED BY SOIL ANIMALS AND VEGETATION OVER TIME.. AN INFILTRATION TEST WILL TELL YOU FOR SURE. 6. APPROPRIATE VOLUMES: RIM ELEVATION SHOULD BE SET SO THAT, AT A MINIMUM, THE VOLUME OF THE WATER QUALITY STORM IS RETAINED ON-SITE. A LARGER VOLUME MAY AND IS PROBABLY APPROPRIATE TO RETAIN ON-SITE, DEPENDING ON THE CONDITIONS IN YOUR JURISDICTION (AVAILABILITY, AND CAPACITY OF EXISTING STORM SEWERS, RAINFALL DISTRIBUTIONS AND GOALS FOR WATERSHED PROTECTION). TO CHOOSE THE RIGHT VOLUME FOR CAPACITY OF THE PLANTER, MODEL/ACCOUNT FOR THE VOLUME OF RUNOFF THAT'S INFILTRATING DURING THE STORM, THE STORAGE CAPACITY OF THE FACILITY, THE RIM ELEVATION, AND THE VOLUME LEFTOVER AT THE END OF THE STORM. 7. A BEEHIVE RIM IS RECOMMENDED BECAUSE IT'S LESS LIKELY TO GET CLOGGED WITH LEAVES AND TRASH. OTHER OUTLETS (DITCH INLET, PLUMBING BENDS PER CITY OF PORTLAND OVERFLOW STRUCTURE,E ETC) COULD BE FINE, BUT WE SUGGEST AVOIDING A FLAT RIM. 8. SIZE THIS PIPE TO CONVEY THE 25-YEAR PEAK FLOW AFTER ATTENUATION BY THE PLANTER. RIM EL=XXX.XX SEE NOTE 6 WIDTH (18" MIN) IE OUT = XXX.XX BEEHIVE RIM SEE NOTE 7 Infiltration Planter SEE NOTE 1 NATIVE PLANTS PER LANDSCAPE ARCHITECT/DESIGNER SEE NOTE 3 EXISTING GRADE SEE NOTE 5 DISTURBED NATIVE SUBGRADE SEE NOTE 5 AREA DRAIN SEE NOTE 2 NON-PERFORATED OVERFLOW PIPE SEE NOTE 8 MIN SUMP DEPTH 3" 3 4"-0 DRAIN ROCK, OPT. FINISH GRADE SEE NOTE x COMPACTED NATIVE SUBGRADE UNDISTURBED NATIVE SUBGRADE SEE NOTE 5 APPROVED FILL, OPT DEEP CURB OR WALL, CONSULT GEOTECHNICAL ENGINEER FOR OVERTURNING ANALYSIS SEE NOTE 4 2-3" MULCH SEE NOTE 3 LID 2.01ai 1 of 1
18-24" AMENDED PLANTING SOIL 6"-12" TYP PONDING DEPTH RIM EL=XXX.XX WIDTH (18" MIN) BEEHIVE RIM NATIVE PLANTS PER LANDSCAPE ARCHITECT/DESIGER DEEP CURB OR WALL, CONSULT GEOTECHNICAL ENGINEER FOR OVERTURNING ANALYSIS FINISH GRADE APPROVED FILL, OPT EXISTING GRADE 2-3" MULCH IE OUT = XXX.XX 18" Infiltration Planter With Planting Soil 3" 3 4"-0 DRAIN ROCK, OPT. DISTURBED NATIVE SUBGRADE AREA DRAIN NON-PERFORATED OVERFLOW PIPE TO APPROVED DISCHARGE POINT MIN SUMP DEPTH COMPACTED NATIVE SUBGRADE UNDISTURBED NATIVE SUBGRADE INFILTRATION PLANTER WITH PLANTING SOIL NOTES DESIGN NOTES: 1. PLANT WITH PLANTS PER LANDSCAPE ARCHITECT DWGS. NATIVE PLANTS ARE PREFERRED, BECAUSE NON-NATIVE AND INVASIVE SPECIES CAN MOVE DOWNSTREAM AND DAMAGE HABITAT. IF NON-NATIVES ARE CHOSEN, BE SURE THAT THEY WILL NOT DAMAGE DOWNSTREAM HABITAT. CONSTRUCTION NOTES: 2. BUILD AND VEGETATE PLANTER AS EARLY AS POSSIBLE TO ESTABLISH PLANTINGS BEFORE DIRECTING STORMWATER RUNOFF TO IT OR DIVERT STORMWATER AROUND FACILITY. PREFERABLY, THIS PERIOD WOULD LAST A MINIMUM OF 3 MONTHS. 3. INFILTRATION AREAS (THE AREA OF THE PLANTER AS DEFINED BY THE TOP ELEVATION OF THE FACILITY) SHALL BE FENCED OFF FROM THE FIRST DAY OF EARTH MOVING UNTIL PROJECT COMPLETION TO PREVENT COMPACTION OF THE SUBGRADE, DIRT TRACKING ONTO ANY LAYER OF THE FACILITY AND STOCKPILING OF CONSTRUCTION MATERIALS THAT MAY CLOG THE SURFACE. 4. DURING EXCAVATION OF NATIVE SOILS TO THE BOTTOM OF THE FACILITY, RAINFALL MAY CAUSE FINES TO CLOG THE SURFACE OF THE FACILITY. IF THE NATIVE SOIL HAS BEEN EXPOSED TO RAINFALL, HAND RAKE THE SURFACE TO A DEPTH OF 3" TO RESTORE INFILTRATION CAPACITY. 5. CALL THE CIVIL ENGINEER, [ENTER NAME HERE] AT [ENTER PHONE NUMBER HERE] 24 HOURS IN ADVANCE OF CONSTRUCTING THIS FACILITY SO VARIATIONS IN THE FIELD CAN BE IDENTIFIED BY CONSTRUCTION INSPECTION. 6. DURING AREA DRAIN INSTALLATION, DISTURB NATIVE SOILS AS LITTLE AS POSSIBLE. LID 2.02 1 of 2
AMENDED PLANTING SOIL MIX SPECIFICATIONS 1. AMENDED PLANTING SOIL MIX SHALL HAVE THE FOLLOWING CHARACTERISTICS: a. 60% LOAMY SAND AND 40% COMPOST. b. ORGANIC CONTENT MATTER FROM 8-10% BY WEIGHT c. CATION EXCHANGE CAPACITY (CEC) GREATER THAN OR EQUAL TO 5 MILLIEQUIVALENTS/100 GRAMS OF DRY SOIL d. 2-5% MINERAL FINES CONTENT e. US STANDARD PERCENT SIEVE SIZE PASSING 3 8" 100 #4 95-100 #10 75-90 #40 25-40 #100 4-10 #200 2-5 f. MINIMUM LONG-TERM HYDRAULIC CONDUCTIVITY OF 1 INCH/HOUR PER ASTM D2434 AT 85% COMPACTION PER ASTM D 1557. g. MAXIMUM IMMEDIATE HYDRAULIC CONDUCTIVITY OF 12 INCHES/HOUR. 2. AMENDED PLANTING SOIL MIX MAY BE CREATED BY TESTING ON-SITE NATIVE SOILS AND MIXING MATERIALS FROM OFF-SITE AS NEEDED TO ACHIEVE THE CHARACTERISTICS DESCRIBED IN NOTE 1 ABOVE. 3. AMENDED PLANTING SOIL MIX SHOULD BE UNIFORMLY MIXED WITH A SOIL MIXER. 4. PLACEMENT OF AMENDED PLANTING SOIL MIX SHALL OCCUR PER THE FOLLOWING GUIDELINES: a. PLACE SOIL IN 12" LIFTS, KEEPING MACHINERY OUTSIDE OF INFILTRATION AREA. b. DO NOT PLACE SOILS IF SATURATED. c. COMPACT EACH LIFT WITH WATER OR BOOT PACKING UNTIL JUST SATURATED TO 85% COMPACTION. DO NOT COMPACT WITH HEAVY MACHINERY OR VIBRATORY COMPACTION. Infiltration Planter With Planting Soil LID 2.02 2 of 2