Rainwater Harvesting Incentive Program

Transcription

1 Rainwater Harvesting Incentive Prgram Water Cnservatin Divisin P. O. Bx 1088 Austin, TX (512) fax /2008

2 PROGRAM GUIDELINES FOR RAINWATER HARVESTING REBATE COMMERCIAL OR RESIDENTIAL General Purpse The City f Austin Water Cnservatin Divisin ffers a financial incentive t encurage the use f rainwater as a supplement t municipal water fr irrigatin use. Each applicatin will be evaluated n a first cme, first served basis. Due t budget issues, all requests may nt be funded. Eligibility Applicant must receive 100% f its water frm the Austin Water Utility r qualifying municipal utility. Rainwater harvesting systems must cllect a minimum f 300 gallns. Life expectancy f the system shuld be a minimum f 20 years. Galvanized tanks are NOT eligible, due t their shrt life span. Hwever, metal tanks with liners may be apprved n a case by case basis, tank specificatins must be submitted. Tanks that are nt UV resistant must be painted r enclsed. The applicant agrees t pen the site t the public if s requested by Water Cnservatin Staff. The applicatin frm includes a simplified methd t calculate the ptimum tank size fr each site. The assumptins in this mdel are designed t reduce peak-day water use during typical dry summer mnths. Alternative apprved calculatin methds may be used. The Texas Guide t Rainwater Harvesting bklet ffers additinal guidance and infrmatin. Yu can btain a cpy thrugh the Texas Water Develpment Bard at r n ur website at Rebate incentives are fr a minimum f $45 (300 gallns) up t a maximum f $500 based n a cmbinatin f 15 cents per galln f tank strage capacity plus half f the cst f specific cmpnents (pad materials, pump, pump switch, and first flush parts) fr a cmplete, peratinal system. Yu may use gravity r pumps fr distributin. The pump cst may include the cst f an in-tank level (flat) switch t shut ff the pump when the water in the tank falls belw a certain level. Prpsed rainwater prjects cannt t be used fr ptable water systems nr can they be cnnected t the ptable water supply system. All applicable building cdes must be fllwed. Call with any applicatin questins. T Apply 1. Submit each f the fllwing: Applicatin Frm Site Plan - Layut f buildings, streets, fences, gates and prpsed tank lcatin(s). System Drawing - Sketch f the prpsed system including all design calculatins, and hw will the water travel frm the rf t the tank t the landscape area. Operatin Guide and Maintenance Written descriptin f hw system will functin and hw maintenance will be perfrmed. Submit yur applicatin packet t: Fax (512) , watercn@ci.austin.tx.us r Mail : Water Cnservatin Rainwater Harvesting P. O. Bx 1088 Austin, TX We will cntact yu either by mail, phne call, r regarding the apprval f yur plan frm City staff. 3. After cmpletin, submit all qualifying receipts. 4. We will cntact yu fr a final inspectin. Rebate checks will be received 3-5 weeks after the final inspectin. 2

3 CALCULATING OPTIMUM TANK SIZE 1. Determine the ptimum tank capacity fr the prperty size. An average f 10 inches falls during the mnths f June, July, August and September; the typical system can cllect 80% since 550 gallns f water can be cllected frm 1000 square feet f rf area during a 1 inch rain. This means 4,400 gallns f water is cllected per 1000 sq. ft. f area. (.80 X [550 gallns X 10 inches] = 4400 gallns) Square ftage f rainwater cllectin area 1000 X 5000 = gallns. 2. Assume that the typical St. Augustine grass lawn requires 1 inch f water per week r abut 560 gallns per 1000 sq. ft. using cnventinal spray irrigatin. During the 16 week peak-water-use perid, the landscape wuld require apprximately 9000 gallns (560 gallns per week X 16 weeks = 8960 gallns) f water per 1000 sq. ft. On average, abut 5000 gallns f that is prvided by summer rainfall. Thus the remaining 4000 gallns wuld be prvided by stred rainwater. Keep in mind that less water may be needed if alternative irrigatin and WaterWise principles (minimal turf, drught tlerant plants, etc.) are emplyed. Square ftage f landscape t be watered 1000 X 4000 = gallns. Optimum tank capacity, fr this prgram, is the lesser f these tw figures; hwever, alternative calculatins are welcme fr cnsideratin. Example The Jnes family has a hme with a 1500 square ft metal rf in Austin. Abut 550 gallns f rainwater can be cllected frm a 1000 square ft rf in a ne inch rain. In the summer mnths (June, July, August, September), Austin receives apprximately 10 inches f rain. Thus, 4400 gallns can be cllected during the summer mnths frm a 1000 square ft rf. (.80 X [550 gallns X 10 inches] = 4400 gallns) Size f cllectin area 1000 sq. ft. X 5000 gallns = gallns f cllected summer rainfall 1500 sq. ft sq. ft. X 5000 gallns = 7,500 gallns f cllected summer rainfall The Jnes family wants t water their St. Augustine lawn with the cllected rainwater. They have apprximately 850 sq. ft. f lawn. A 1000 sq. ft St. Augustine lawn uses apprximately ne inch r 560 gallns f water per week. Abut 9000 gallns f water will be needed during the 16 weeks f the summer mnths fr 1000 sq. ft. f lawn. During a ne inch rain, a 1000 sq. ft. St. Augustine lawn will receive apprximately 550 gallns f water. The 1000 sq. ft. lawn will receive abut 5000 gallns f water frm the average 10 inches f summer rainfall. Thus, an additinal 4000 gallns f water shuld be prvided by cllected rainfall fr this lawn. Size f lawn (sq. ft.) 1000 sq. ft. X 4000 gallns = gallns f supplemental water 850 sq. ft sq. ft. X 4000 gallns = 3400 gallns f supplemental water The ptimum tank size is 3,400 galln rainwater system. Use this wrksheet t keep track f yur price estimates. PRICE ESTIMATE WORKSHEET Tank (s) Tank type (material*): fiberglass, plyprpylene, cncrete, stne, ther *REMEMBER UNLINED, GALVANIZED METAL TANKS ARE NOT ELIGIBLE FOR THE REBATE. 3

4 Tank size (in gallns) Tank dimensins (ft.) Cst f tank and delivery First Flush Cmpnents First flush is a system f piping t cllect debris befre it enters the tank. Refer t Rainwater Cllectin with Several Optins schematic drawing n the Water Cnservatin web site ( Pad Cnstructin Material*: gravel, sand, cncrete *Wden, abve grund platfrms will nt be apprved. Site must be level. Pump and Optinal Flat Level Switch Is a pump necessary? If yes, cnsider installing a flat level switch t prlng the life f the pump. Hw far d yu want t pump the water? What hrsepwer d yu need? OPERATION AND MAINTENANCE Operatin Guide Referring t yur site plan and system drawing, describe in writing hw the system will functin. Include details such as type and size f cllectin (rf) surface; tank size, cmpsitin and lcatin; piping and first flush details; pump type and lcatin r ther water distributin methd. (Yu may attach separate sheets) Maintenance Plan Prvide a detailed plan n hw maintenance will be dne, including scheduled bacteria cntrl measures if spray irrigatin is t be used. (Yu may attach separate sheets) 4

5 RAINWATER HARVESTING INCENTIVE APPLICATION FORM Name (as it appears n water bill) Physical Address: Zip Mailing address (if different) Zip Circle ne: Residential Nnprfit Cmmercial Cntact persn Phne Fax address: City f Austin Water Utility accunt number If nt Austin Water Utility custmer, prvide a cpy f yur water bill. Cnstructin start date Estimated cmpletin date Applicatin Packet Must Include All The Fllwing: Site Plan System Drawing Operatin Guide Maintenance Plan Applicatin Frm Agreement The gal f the rainwater harvesting incentive prgram is t prvide demnstratin sites that intrduce the cncept f n-site rainwater harvesting t Austin citizens. The undersigned participant understands and agrees that rebated systems must remain peratinal fr five years, r the City is entitled t recver a prrated prtin f the incentive. The applicant agrees t allw public access t the system if requested by Water Cnservatin Staff. Only custmers f the Austin Water Utility (r custmers whse supplier receives 100% f its water frm the Utility) are eligible. The City f Austin makes n claims as t the safety r reliability f installed equipment r resulting water. The participant agrees that the water is t be fr nn-ptable uses nly. I agree t the terms f Rainwater Harvesting Incentive Prgram. Signature* Print name Date (Same as n water bill) (Same as n water bill) Title fr cmpany name* Date *If applicant is a cmpany r nnprfit, wner r authrized fficer must sign. City f Austin Use Only--Rebate Calculatin: Tank Size (gallns) X.15 (cents) = Ttal $ Pump and switch X. 5 (50 %) = up t $ 100 Pad Materials X. 5 (50 %) = up t $ 100 1st Flush Parts X. 5 (50 %) = up t $ 35 Ttal Rebate nt t exceed $ 500 Ttal Rebate 5