Rainwater Basics:

Rainwater Design

Pre-Design

Design

Installation

Purchasing

Below are some tips hopefully making it easier for you design your rainwater system.  No two systems are exactly alike and often there are multiple ways to achieve the same goal!
Pre-design Considerations: What   are   going   to   use   the   water   for?      Tank   size   is   often   determined   by   what   you   want   to   use   the   water   for.   We can use 70% of our water on irrigation!  How much can you collect?  Most people are shocked to learn how much water they can collect.    In   Central   Texas,   where   we   get   about   32"   of   rain   in   a   normal   year,   a   one   story   2000   square   foot   house   can collect   35,000   gallons   of   rainwater   a   year.      Don't   design   a   system   that   tries   to   direct   that   much   rain   into   a   300 gallon tank! How   much   space   do   you   have?      Lots   of   times   space   is   a   limiting   factor.      Are   there   trees   that   prevent   installation of   large   tanks?      How   high   are   the   eaves   on   your   house?      Seven   foot   tall   tanks   work   well   for   eight   foot   eaves.      Is there a fence in the way?  We've temporarily removed fencing to get tanks into place. Are   you   applying   for   a   rebate?      Many   municipalities   offer   rebates   from   $0.50   /   gallon   up   to   $1.00   /   gallon.      In some instances you need to be pre-approved before you purchase and install your tank. Are   you   part   of   an   HOA   or   POA?      Great   news!      In   2013   the   Texas   Legislature   passed   a   law   prohibiting   HOA's from   banning   rainwater   harvesting   systems.      They   might   limit   the   location,   but   they   must   allow   rainwater tanks.  If your HOA is unfamiliar with this law, tell them to see Texas Property Code Sec 202.007.
Designing Your System: Sizing the tank:  A one inch rain collects 600 gallons per 1000 square feet of covered space (roof).  Rule of    thumb:   plan   for   aRainwater   Tank   with   First   Flush   Diverter   2" rain   event.      Therefore   if   you   are   collecting   off   of   500   square feet,   that   will   produce   300   gallons   on   a   1"   rain.      Therefore      500 gallon   or   larger   tank   would   be   appropriate.      For   larger   surface areas, consider using multiple tanks. Size   the   inlet   and   overflow:   If   your   tank   is   1000   gallons   or   less, you   are   probably   only   collecting   from   one   downspout.      In   that case   a   3"   inlet   is   probably   fine.      If   you   have   6"   gutters   you might    want    to    go    with    a    4"    inlet.        If    you    have    multiple downspouts,   you   can   still   go   with   3"   PVC   piping,   but   at   some point expand to 4" and have a 4" inlet.  Rule of thumb:  match the overflow size to the inlet size. Choose   an   outlet   size:   If   you   are   just   going   to   attach   a   garden hose,   go   with   a   3/4"   bulkhead   connection.      That   will   allow   you to screw in a spigot. Pump   or   no   pump:   Many   people   want   to   pressurize   the   water   to   be   able   to   pump   into   the   house   or   run   an irrigation   system.      Within   city   limits   pressurized   systems   need   backflow   protection   devices.      Another   option   is   to buy a submersible sump pump. Keeping   debris   out   of   your   tank:      If   your   gutters   clog   with   leaves   your   tank   will   clog   will   leaves   if   you   just   run   it directly   into   the   tank.      Gutters   screens   are   your   first   line   of   defense.      You   may   also   choose   to   use   a   basket   on   the tank.If neither of those options are doable, a first flush diverter is recommended.
2500 Gallon Rainwater Tank with First Flush Diverter
Installing Your System: The   tank   needs   to   be   installed   on   a   solid   base.      We   recommend   crushed   granite   or   a   similar   base.      The   simplest thing   to   do   is   get   some   treated   landscape   timbers   and   form   a   square   about   a   foot   wider   than   your   tank.      Fill with   2"   -   3"   of   crushed   granite   and   tamp   down.      The   tank   can   sit   directly   on   the   crushed   granite.      Of   course,   a concrete   pad   also   works!      Keep   in   mind   water   weighs   8.3   pounds   per   gallon,   so   a   2500   gallon   tank   weighs   over 10 tons when full! Moving   the   tank   into   place:      Large   tanks   slide   easily   across   2   X   4's.   or   better   yet   PVC   pipes.   Tanks   can   also   be tipped on a bottom edge and rolled.  Do not lay a large tank on its side and roll it! Positioning   of   fittings:      Generally   do   not   position   the   overflow   above   the   outlet.      If   you   decide   to   plumb   the overflow,   the   pvc   pipe   will   come   down   where   your   outlet   is!      The   overflow   should   channel   water   away   from   the tank and house towards a low lying area. Bulkhead   connectors:   Important!!!   These   are   threaded   on   both   the   inside   and   outside.      You   will   only   be   able   to screw   things   into   the   inside   of   the   bulkhead!      The   outside   threads   are   reversed   thread   and   only   accept   the locknut.  Therefore a 3/4" bulkhead accepts a 3/4" spigot, for example. Painting   the   PVC:      Choose   a   metallic   gray   spray   paint   to   make   the   overflow   and   inlet   look   like   metal.      Rustoleum (TM) makes a good product available at The Home Depot. Securing   the   top:      The   top   of   your   tank   needs   to   be   secured   in   place   so   it   doesn't   blow   off.      Four   self   tapping sheet   metal   screws   should   be   included   with   your   tank.      We   recommend   pre-drilling   the   holes   about   an   1   1/2" from the edge.  There is a lip  at the top of the tank.
Purchasing Your Tank: Lead times are 3 - 4 weeks.   A 50% deposit will get you in the production schedule. We   accept   cash,   checks,   and   credit   cards.      We   will   email   you   an   invoice   and   you   can   pay   online   through   a secure transaction portal. We   do   not   need   the   tank   inlet/outlet   form   with   your   order   as   that   is   the   last   step   in   the   process,   but   the sooner the better! We   will   contact   you   when   the   tank   is   ready   to   schedule   pick   up   or   delivery.      Saturdays   are   always   an   option but we need to plan for it! We can deliver or ship UPS or arrange for direct transport.  Shipping can add one to three weeks.
On   a   1000   square   foot   structure, you    can    collect    600    gallons    of water from a 1" rain. Rule   of   thumb:   plan   your   system to hold a 2” - 3” rain event.   Over    the    course    of    year,    many clients    could    collect    30,000    or more gallons of rainwater. In    central    Texas,    a    400    gallon tank      typically      fills      30      times annually   when   collecting   from   a 500   square   foot   structure   -   your garage for example.   Plants   love   rainwater.      It   picks   up nitrogen    as    it    falls    to    the    earth and    does    not    have    any    harsh chemicals or salts.
Design Ideas:
300 Gallon Metal Rain Tank
300 Gallon Tank on Stand
400 Gallon Metal Rain Tank with First Flush
400 Gallon with First Flush
400 Gallon Rainwater Tank with Basket Inlet
400 Gallon with Basket
Questions?  Need more help?  Call or email! sales@TexasMetalTanks.com 512-565-0875
830 Gallon Galvanized Rainwater Tank with Basket Inlet
Note:    If    your    tank    is    collecting from    one    downspout,    a    basket inlet   is   often   easiest.      Simply   spin the   top   so   the   basket   is   under   the downspout   then   secure   with   four screws.
300 Gallon Galvanized Rainwater Tank
Pads          of          crushed          granite (decomposed   granite)   or   pea   gravel are       simple       and       well       suited.         Limestone    block,    brick,    pavers,    or landscape   timbers   can   be   used   to form the pad.

Rainwater Design

Pre-Design

Design

Installation

Purchasing

Below are some tips hopefully making it easier for you design your rainwater system.  No two systems are exactly alike and often there are multiple ways to achieve the same goal!
Pre-design Considerations: What   are   going   to   use   the   water   for?      Tank   size   is   often   determined   by what   you   want   to   use   the   water   for.   We   can   use   70%   of   our   water   on irrigation!  How   much   can   you   collect?      Most   people   are   shocked   to   learn   how   much water they can collect.    In   Central   Texas,   where   we   get   about   32"   of   rain   in   a   normal   year,   a   one story   2000   square   foot   house   can   collect   35,000   gallons   of   rainwater   a year.      Don't   design   a   system   that   tries   to   direct   that   much   rain   into   a   300 gallon tank! How   much   space   do   you   have?      Lots   of   times   space   is   a   limiting   factor.      Are there   trees   that   prevent   installation   of   large   tanks?      How   high   are   the   eaves on   your   house?      Seven   foot   tall   tanks   work   well   for   eight   foot   eaves.      Is there   a   fence   in   the   way?      We've   temporarily   removed   fencing   to   get   tanks into place. Are   you   applying   for   a   rebate?      Many   municipalities   offer   rebates   from $0.50   /   gallon   up   to   $1.00   /   gallon.      In   some   instances   you   need   to   be   pre- approved before you purchase and install your tank. Are   you   part   of   an   HOA   or   POA?      Great   news!      In   2013   the   Texas   Legislature passed    a    law    prohibiting    HOA's    from    banning    rainwater    harvesting systems.      They   might   limit   the   location,   but   they   must   allow   rainwater tanks.      If   your   HOA   is   unfamiliar   with   this   law,   tell   them   to   see   Texas Property Code Sec 202.007.
Designing Your System: Sizing   the   tank:      A   one   inch rain   collects   600   gallons   per 1000   square   feet   of   covered space (roof).  Rule of    thumb:   plan   for   aRainwater Tank   with   First   Flush   Diverter 2"    rain    event.        Therefore    if you   are   collecting   off   of   500 square   feet,   that   will   produce 300    gallons    on    a    1"    rain.      Therefore          500     gallon     or larger        tank        would        be appropriate.            For      larger surface   areas,   consider   using multiple tanks. Size   the   inlet   and   overflow:   If   your   tank   is   1000   gallons   or   less,   you   are probably   only   collecting   from   one   downspout.      In   that   case   a   3"   inlet   is probably   fine.      If   you   have   6"   gutters   you   might   want   to   go   with   a   4"   inlet.      If you   have   multiple   downspouts,   you   can   still   go   with   3"   PVC   piping,   but   at some point expand to 4" and have a 4" inlet.  Rule of thumb:  match the overflow size to the inlet size. Choose   an   outlet   size:   If   you   are   just   going   to   attach   a   garden   hose,   go   with a 3/4" bulkhead connection.  That will allow you to screw in a spigot. Pump   or   no   pump:   Many   people   want   to   pressurize   the   water   to   be   able   to pump    into    the    house    or    run    an    irrigation    system.        Within    city    limits pressurized   systems   need   backflow   protection   devices.      Another   option   is to buy a submersible sump pump. Keeping   debris   out   of   your   tank:      If   your   gutters   clog   with   leaves   your   tank will   clog   will   leaves   if   you   just   run   it   directly   into   the   tank.      Gutters   screens are   your   first   line   of   defense.      You   may   also   choose   to   use   a   basket   on   the tank.If    neither    of    those    options    are    doable,    a    first    flush    diverter    is recommended.
Installing Your System: The   tank   needs   to   be   installed   on   a   solid   base.      We   recommend   crushed granite   or   a   similar   base.      The   simplest   thing   to   do   is   get   some   treated landscape   timbers   and   form   a   square   about   a   foot   wider   than   your   tank.     Fill   with   2"   -   3"   of   crushed   granite   and   tamp   down.      The   tank   can   sit   directly on   the   crushed   granite.      Of   course,   a   concrete   pad   also   works!      Keep   in mind   water   weighs   8.3   pounds   per   gallon,   so   a   2500   gallon   tank   weighs over 10 tons when full! Moving   the   tank   into   place:      Large   tanks   slide   easily   across   2   X   4's.   or better   yet   PVC   pipes.   Tanks   can   also   be   tipped   on   a   bottom   edge   and rolled.  Do not lay a large tank on its side and roll it! Positioning   of   fittings:      Generally   do   not   position   the   overflow   above   the outlet.      If   you   decide   to   plumb   the   overflow,   the   pvc   pipe   will   come   down where   your   outlet   is!      The   overflow   should   channel   water   away   from   the tank and house towards a low lying area. Bulkhead   connectors:   Important!!!   These   are   threaded   on   both   the   inside and   outside.      You   will   only   be   able   to   screw   things   into   the   inside   of   the bulkhead!      The   outside   threads   are   reversed   thread   and   only   accept   the locknut.  Therefore a 3/4" bulkhead accepts a 3/4" spigot, for example. Painting   the   PVC:      Choose   a   metallic   gray   spray   paint   to   make   the   overflow and   inlet   look   like   metal.      Rustoleum   (TM)   makes   a   good   product   available at The Home Depot. Securing   the   top:      The   top   of   your   tank   needs   to   be   secured   in   place   so   it doesn't   blow   off.      Four   self   tapping   sheet   metal   screws   should   be   included with   your   tank.      We   recommend   pre-drilling   the   holes   about   an   1   1/2" from the edge.  There is a lip  at the top of the tank.
Purchasing Your Tank: Lead times are 3 - 4 weeks.   A 50% deposit will get you in the production schedule. We   accept   cash,   checks,   and   credit   cards.      We   will   email   you   an   invoice and you can pay online through a secure transaction portal. We   do   not   need   the   tank   inlet/outlet   form   with   your   order   as   that   is   the last step in the process, but the sooner the better! We    will    contact    you    when    the    tank    is    ready    to    schedule    pick    up    or delivery.  Saturdays are always an option but we need to plan for it! We   can   deliver   or   ship   UPS   or   arrange   for   direct   transport.      Shipping   can add one to three weeks.
Questions?  Need more help?  Call or email! sales@TexasMetalTanks.com 512-565-0875