Kewajiban Masyarakat Membuat Sumur Resapan BERITA JAYA NOMOR : 48 TAHUN IX
28 PEBRUARI 2000
Sumur Resapan adalah sistem resapan buatan yang dapat menampung air hujan, baik dari permukaan tanah maupun dair air hujan yang disalurkan melalui atap bangunan, dapat berbentuk sumur. Kolam dengan resapan, saluran porous, saluran resapan dan sejenisnya. Manfaat Melestarikan dan memperbaiki kualitas lingkungan, membantu menanggulangi kekurangan air bersih dan menambah potensi air tanah, mengurangi erosi permukaan tanah, menampung-menyimpan dan menambah kandungan air tanah, mengurangi limpahan air permukaan tanah, melestarikan dan menyelamatkan sumber daya air tanah serta mengurangi debit genangan dan banjir. Kewajiban Setiap pemilik/penghuni/pengelola bangunan wajib membuat sumur resapan. Dalam pembuatan sumur resapan dimaksud dapat diminta keterangan dari Suku Dinas Pengawasan Pembangunan Kota(Sudin P2K) Kotamadya setempat. Jenis-jenis Sumur Resapan Untuk rumah bertalang, sumur resapan air hujan dengan dinding pasangan batu, sumur resapan air hujan dengan pasangan buis beton. Untuk rumah tidak bertalang, sumur resapan air hujan dengan pasangan batu dan diisi dengan batu-batuan, sumur resapan dengan pasangan buis beton, sumur resapan air hujan dengan pasangan batu bata, harus ada saluran penghantar menuju ke sumur resapan. Persyaratan Penempatan sumur resapan dapat dibuat pada seluruh pekarangan, dapat dibuat pada daerah yang tidak mudah longsor (labil), tidak dibuat di lokasi timbunan sampah dan atau tanah yang mengandung bahan pencemar, dibuat sejauh mungkin dari rembesan septik tank. Contoh Volume Sumur Resapan Pada Kondisi Permeabilitas Tanah Rendah No. 1. 2. 3. 4. 5. 6.
Luas Kavling (M2) 50 100 160 200 300 400
Volume sumur resapan Volume sumur resapan ada saluran drainase tanpa ada saluran drainase sebagai pelimpah = VI (M3) sebagai pinyimpinan = V2,M3 1,3 s.d 2,1 M� 2,6 s.d 4,1 M� 3,9 s.d 6,2 M� 5,2 s.d 8,2 M� 7,8 s.d 12,3 M� 10,4 s.d 16,4 M�
21 s.d M� . 6,2 s.d 11,9 M� 8,2 s.d 25,9 M� 12,3 s.d 23,4 M� 13,4 s.d 31,6 M�
7. 8. 9. 10. 11. 12. dst.
400 600 700 800 900 1000 .
10,4 s.d 16,4 M� 15,6 s.d 24,6 M� 18,2 s.d 28,7 M� 20,8 s.d 32,8 M� 23,4 s.d 36,8 M� 26 s.d 41 M� .
13,4 s.d 1,6 M� 24,8 s.d 47,4 M� 28,7 s.d 155,3 M� 32,8 s.d 63,2 M� 36,8 s.d 71,1 M� 41 s.d 79 M� .
Penjelasan : - Permeabalitas tanah rendah adalah rembesan air dalam tanah sedemikian rupa sehingga air tampungan dalam sistemresapan baru habis dalam 24 jam sejak hujan pertama jatuh. - Apabila ada data-data lengkap mengenai koefisien permeabilitas tanah, data-data hujan dan lain-lain dapat diajukan dengan perhitungan tersendiri berdasarkan rumur-rumus dari para ahli dibidang sistem sumur resapan. - Apabila data-data yang dimaksud tidak lengkap, maka dapat ditetapkan : � VI sebesar = 30 liter tiap 1 M2 luas Kavling. � V2 sebesar = 50 liter tiap 1 M2 luas Kavling. (wr) http://www.jakarta.go.id/bjaya/bj48c.htm, 10 Januari 2007, 14.40 WIB Jenis-Jenis sumur resapan yaitu 1.
Untuk rumah bertalang Dapat berupa sumur resapan air hujan dengan dinding pasangan batu atau sumur resapan air hujan dengan pasangan buis beton.
2.
Untuk rumah tidak bertalang
Dapat berupa sumur resapan dengan pasangan buis beton atau sumur resapan air hujan dengan pasangan batu bata yang harus ada saluran penghantar menuju ke sumur resapan.
http://bplhd.jakarta.go.id/sr.php, 10 Januari 2007, 13.25 WIB
Bentuk dan Ukuran Sumur adalah sebagai berikut : 1 Sumur resapan air hujan berbentuk segi empat atau lingkaran; 2 Ukuran minimum sisi penampang atau diameter adalah 0,8 m 3 Ukuran maksimum sisi penampang atau diameter adalah 1,4m 4 Ukuran pipa masuk diameter 110 mm; 5 Ukuran pipa pelimpah diameter 110 mm;
6 Ukuran kedalaman maksimum dapat dilihat pada table
TABEL UKURAN KEDALAMAN DAN TIPE KONSTRUKSI KEDALAMAN
TIPE KONSTRUKSI
Maksimum 1,5 m
I
Maksimum 3 m
II
Maksimum muka air tanah
IIIa, IIIb, IIIc
Persyaratan Penempatan sumur resapan dapat dibuat pada seluruh pekarangan, dapat dibuat pada daerah yang tidak mudah longsor (labil), tidak dibuat di lokasi timbunan sampah dan atau tanah yang mengandung bahan pencemar, dibuat sejauh mungkin dari rembesan septik tank. http://www.kimpraswil.go.id/Ditjen_kota/sumur.htm, 10 Januari 2007, 14.33 WIB
SUMUR RESAPAN ALTERNATIF 1 http://www.kimpraswil.go.id/Ditjen_kota/alt1.htm, 10 Januari 2007, 14.23 WIB
http://www.kimpraswil.go.id/Ditjen_kota/alt_2.htm,10 Januari 2007, 14.23 WIB
Contoh penerapan sumur resapan pada rumah tinggal
Harvesting Rainwater for Landscape Use Patricia H. Waterfall Etension Agent University of Arizona Cooperative http://ag.arizona.edu/pubs/water/az1052/harvest.html; Landscape Use; 14 Maret 2008, 10.42 WIB
Harvesting
Rainwater
for
Introduction In the arid Southwest, rainfall is scarce and evapotranspiration ( ETo ) 1 rates are high. In Tucson the average historical ETo rate is approximately 77 inches and average rainfall is 11 inches, in Phoenix average historical ETo is approximately 80 inches and average rain is 10 inches. For Tucson, this is a 7:1 ratio between water that is evapotranspired and what is available from rainfall, for Phoenix the ratio is 8:1. Only natives and some desert-adapted plants (plants from other desert areas that can flourish in our soils and our climate) can live on 10 or 11 inches of annual rainfall. Other desert-adapted plants may require some supplemental irrigation. Plants from non-arid climates require a great deal of supplemental irrigation.
Series of planted water harvesting basins on a slope. Harvesting rainwater can reduce the use of drinking water for landscape irrigation. Coupled with the use of native and desert-adapted plants, rainwater harvesting is an effective water conservation tool because it provides "free" water that is not from the municipal supply. There are many benefits to harvesting rainwater. Water harvesting not only reduces dependence on ground water and the amount of money spent on water, but also reduces offsite flooding and erosion by holding rainwater on the site. If large amounts of water are held in highly pervious areas (areas where water penetrates easily), some of the water may percolate to the water table. Rainwater is a clean, salt-free source of water for plants. In addition, rainwater harvesting can reduce salt accumulation in the soil which can be harmful to root growth. When collected, rainwater percolates into the soil, forcing salts down and away from the root zone area. This allows for greater root growth and water uptake, which increases the drought tolerance of plants. Limitations of water harvesting are few and are easily met by good planning and design.
Water harvesting is the capture, diversion, and storage of rainwater for plant irrigation and other uses. It is appropriate for large scale landscapes such as parks, schools, commercial sites, parking lots, and apartment complexes, as well as small scale residential landscapes. System design ranges from simple to complex. But whether your landscape is large or small, the principles outlined in this manual apply. There are many water harvesting opportunities on developed sites, even very small yards can benefit from water harvesting. And, water harvesting can easily be planned into a new landscape during the design phase.
Parking lot draining into concave lawn area. Water Harvesting System Components A rainfall water harvesting system has three components: the supply (rainfall), the demand (landscape water requirement), and the system that moves the water to the plants. Storage is an additional element which is optional.
Simple system - Roof catchment, channel, and planted landscape holding area.
Simple system — Roof catchment, gutters, downspouts, and bermed landscape holding area.
Simple system — Roof catchment, gutters, downspouts, and french drain. Rainfall. Rainwater runoff refers to rainwater which flows off a surface. If the surface is impervious (water cannot penetrate it), then runoff occurs immediately. If the surface is pervious (water can penetrate it), then runoff will not occur until the surface is saturated. Runoff can be harvested (captured) and used immediately to water plants or can be stored for later use. Several factors affect runoff, the most important being the amount of rainfall. Rainfall duration refers to the length of time the rain falls, the longer the duration, the more water available to harvest. The intensity of the rainfall affects how soon the water will begin to run off and also how fast it runs off. The harder it rains and the longer it lasts the more water there is for harvesting. The timing of the rainfall is also important. If only one rainfall occurs, water percolates into the dry soil until it becomes saturated. If a second rainfall occurs soon after the first, more water may runoff because the soil is already wet. Plant Water Requirement. The type of plants selected, their age and size, and how closely together they are planted all affect how much water is required to maintain a healthy landscape. Because rainfall is scarce in arid regions, it is best to select plants with low water requirements and control planting densities to reduce overall water need. Native plants are well-adapted to seasonal, short-lived water supplies, and most desert-adapted plants can tolerate drought, making them good choices for landscape planting. Water Collection and Distribution System. Water harvesting systems range from simple to complex. In a simple system the rainwater is used immediately. Most homeowners can design simple water harvesting systems to meet the needs of their existing site. Designing water harvesting systems into new construction allows the homeowner to be more elaborate and thorough in developing a system. In the case of very simple systems, the pay back period may be almost immediate. A simple system usually consists of a catchment area, and a means of distribution, which operates by gravity. The water is deposited in a landscape holding area, a concave area or planted area with "edges" to retain water, where it can be used immediately by the plants. Water collects on roofs, paved areas or the soil surface. A good example of a simple system is water dripping from the edge of the roof to a planted area or diversion channel directly below. Gravity moves the water to where it can be used. In some cases, small containers are used to hold water for later use. A catchment area is any area from which water can be harvested. The best catchments have hard, smooth surfaces, such as concrete or metal roofing material. The amount of water harvested depends on the size, surface texture, and slope of the catchment area.
The distribution system connects the catchment area to the landscape holding area. Distribution systems direct water flow, and can be very simple or very sophisticated. For example, gutters and downspouts direct roof water to a holding area, and gently sloped sidewalks distribute water to a planted area. Hillsides provide a perfect situation for moving water from a catchment area to a holding area. Channels, ditches, and swales all can be utilized to move water. Elaborate open channel distribution systems may require gates and diverters to direct the water from one area to another. Standard or perforated pipes, and drip irrigation systems can be designed to distribute water. Curb cutouts can channel street or parking lot water to planted areas. If gravity flow is not possible, a small pump may be required to move the water. Landscape holding areas store water in the soil for direct use by the plants. Concave depressions planted with grass or plants serve as landscape holding areas, containing the water, increasing water penetration, and reducing flooding. Depressed areas can be dug out, and the extra soil used to berm (a bank of soil used to retain water) the depression. With the addition of berms, moats, or soil terracing, flat areas also can hold water. One holding area or a series of holding areas can be designed to fill and then flow into adjacent holding areas via spillways (outlets for surplus water). Soil erosion can be a problem with water moving quickly over the soil surface. Basins and spillways help reduce this. Crescent-shaped berms constructed around the base of the plant on the down-hill side are useful on slopes for slowing and holding water. Gabions (a stationary grouping of large rocks encased in wire mesh) are widely used to contain water and reduce erosion. French drains (holes or trenches filled with gravel) can also hold water for plant use. And lastly, pervious paving materials, such as gravel, crushed stone, open paving blocks, and pervious paving blocks, allow water to infiltrate into the soil to irrigate plants with large, extensive root systems, such as trees.
Crescent-shaped landscaped holding areas on a slope. Simple Water Harvesting System Design And Contruction By observing your landscape during a rain, you can locate the existing drainage patterns on your site. Identify low points and high points. Utilize these drainage patterns and gravity flow to move water from catchment areas to planted areas. If you are harvesting rainwater from the roof, extend downspouts to reach planted areas or provide a path, drainage, or hose to move the water where it is needed. Take advantage of existing sloped paving to catch water and redistribute it to planted areas.The placement and slope of new paving can
be designed to increase runoff. If sidewalks, terraces, or driveways are not yet constructed, slope them two percent (1/4 inch per foot) toward planting areas and utilize the runoff for irrigation. Bare dirt can also serve as a catchment area by grading the surface to increase and direct runoff. Next locate and size your landscape holding areas. Locate landscape depressions that can hold water or create new depressions where you want to locate new plants. Rather than digging a basin around existing plants, construct berms or moats on the existing surface to avoid damaging roots. Do not mound soil at the base of trees or other plants. Holding areas around existing plants should extend beyond the "drip line" to accommodate and encourage extensive root systems. The more developed a plant's root system, the more drought tolerant the plant becomes because the roots have a larger area to find water. For new plantings, locate the plants at the upper edge of concave holding areas to encourage extensive rooting and avoid extended inundation (flooding). With either existing or new landscapes you may want to connect several holding areas with spillways or channels to distribute the water throughout the site.
Site plan showing drainage patterns and landscape holding areas (aerial view). Selecting Plant Material. Proper plant selection is a major factor in the success of a water harvesting project. Native and desert-adapted plants can be grown successfully using harvested rainwater for irrigation. Some plants cannot survive in the actual detention area if the soil is saturated for a long period of time. Careful plant selection for these low lying areas is important. Select plants that can withstand prolonged drought and prolonged inundation--native plants or plants adapted to the Sonoran Desert. If plants are going to be planted in the bottom of large, deep basins, low water use, native riparian trees may be the most appropriate choice (hackberry, desert willow, acacia, mesquite). To take advantage of water free-falling from roof downspouts (canales) plant large rigid plants where the water falls or hang a large chain from the downspout to the ground to disperse and slow the water. Provide a basin to hold the water for the plants and also to slow it down. It may be necessary to use rocks or other hard material to break the fall and prevent erosion. If this is a sloped site, large, connected, descending holding areas can be constructed for additional plants.
Tree dripline and basin edge. Seeding is another alternative for planting holding basins. Select seed mixes containing native or desert-adapted wildflowers, grasses, and herbaceous plants. Select annual plants for instant color and perennial plants for extended growth. Perennial grasses are particularly valuable for holding the soil and preventing erosion and soil loss.
Pervious paving block with grass. Construction Hints. If you are going to dig, particularly if you are going to be using a bobcat, small tractor, or rototiller, call Arizona Blue Stake (1_800_782_5348) to locate where utility lines come into your property. This will eliminate leaks and breaks. Even if you are constructing a simple system with a rake and shovel, be aware of utility line locations. Soils in the landscape holding areas should not be compacted because this inhibits the water moving through the soil. If the soil is compacted, loosen it by tilling. If the soil is too sandy and will not hold water for any length of time, you may wish to add composted organic matter to the soil to increase moisture holding potential (This is not necessary with native or desert-adapted plants). After planting apply a 1 1/2 _ 2 inch layer of mulch to reduce evaporation. System Maintenance. Developing a water harvesting system is actually an on-going process that can be improved and expanded over time. Water harvesting systems are always in a state of "construction". It is necessary to reality test your system during rain events. Determine whether the water is moving where you want it, or whether you are losing water. Also determine if the holding areas are doing a good job of containing the water. Make changes as your system requires. As time goes on you may discover additional areas where water can be harvested and where water can be channeled. Water harvesting systems should be inspected before each rainy season and ideally after every rain event to keep the system operating at optimum performance.
