DNERSON anus AND mums Diversion drains are genlly sloping drains used lo lead walk! away lrnni valleys and siredrris and rum sloragis and irriglllon syslenis, or Inbo sand laeds or swala lor absorpcion. ll low earrlrewalls are raised arross ihe flow channels or larger diversion drains, ihese lheri id as a series ol rniniswales ior rpe e lree sues, while surplus waler llows on in siorages. Diversion drains diner horn swales iri lhal lhey are lriiill lo lioio aller rain lirorn overland llow or norn leeder siroainsl They are lire riorrrial and essenilal eonnedors ol daoi series bill" on ihe xeyline sysierns, so lhal ihe overflow oi one darn enlers uie leeder channel 0! ihe nerl. slash diversion sysieins need carelul planning and survey, wish drain bases sloping as hnle as P6000 in line sands. Darn eresls and irrigalion drains need equally carelnl placerrieril. Evan wilhoul e slreain Intake, diversion drains wIl| gaiher waler lrorri overland now in as linle as 14.5 cm ll/l inehl 0! rain over 14 hours, ro lhal isolaied dams are normally find wllh diversion drains even in quile dry eounlry. Diversion drains can be led lo broad level swaler in drylands, or rnade o: sirnple eoncrele or sione walls across solid rock laces ln ihe Canary islands, lhese gaiher nxk run-oil which is led lo undergmund cave slorages or large open lanla. Slmple sliding gaies ms or in ihe downhill banks ol such drains allnw eonlrolled now, conlrolled irrigalion, and iin noodsl oyepassing of dams, Splll gales ran loe nxsn leonerele slide holders arid apronrl or MOVEABLE lplaslie sheels weighled wxlh a chain sewn iiilp lhe lool, and supporled aeross ihe drain by a lighl pipe sleeved iniir lhe iopl lheso laller are called -nags- irignie 7.27), slide gales an open on m ridge lines, and waler lhen spreads downlull. while plaslic ilags an be placzd and laheri up ai any pouil along a drain This enables one or iwo people lo waler mm ha «no—6m aeresl iii a rruvrniog li rs also an eneciive wridlire cenlrel syslern in loresled areas. Forsophislicaied wildlirecrr irrigaiion eonlrol, holh slide gales and dainelaase gale valves can he rerriolely operaled, by radio signal and slorage balleries or huned eleclaical eonduils, lo power srnall oiolors m hydraulic slides A eornplele wlldfue mnliol can b: achieved by darris and sheei irrigaliorr, and using inn-lied senaers and airlooialae sprflbgik: such syslerns reineve ihe i-isk lor limhyum, and allow ioresis io regenerale iri seoriond :ms, p mplpr drains. These drainsmr rarher, sealed Inlemflmifid in lhe opposrle lense lo diversion drains These eorihworlss are specilioally designed (by Harry Whmlnglun oi Wrsl Auslralial lo prevenl overland wdluflow and walerloggirig which I“; ihe elleel or collapsing che drylarid valley or downslope soils 0! a desen ioil ealena Thus. ihey ideally lolally inlercepi overland now, and direel ii lo sirearns or vallgy run—olls.1hey can he envelope a are swales, laui lhey diner riorn diversion drains and swales in llial lheir (onslmmon alwlyd involves ihe rainrnirig (by bulldozu oladel ol subsoil layers hard againsl ihe duwnhl“ hanlc. This ellecilvely prevenls or impedes waier seepape lhrougri ihe downhill wall ol ihe inleirepler bank. Moreover, lhey are always 1.52.5 iii (SH?) deep, carefully rpaeed, and elleclively slep run only overland now bu| also sall waier seepagsr in shallow sand searris lri elreel, lhey isolaie large lrloeld ol soil horn walerlogging and sail seepage Alier ihis preparalion, irees can or planled in previously desenined sails Where deeper sand seams carrying sally walor are loomed, lhase can be ireiiched ool and slapped with a veriical plaalie barrier, backed by corripaeled clay on ihe uphill side. Made lo lluw al I‘WD lo used crosseslope inlercrpiorr elieclively col up incipienl or degraded croplands sublecl lo desenineanon inio blocks or rm rn lsan leell lo a maximum ol 3m m19851eel) Wide. isolaling eaeh blo(k lrorri llooding and ihe sally cascade [low horn uphill. surplus waier is carried on in slreanis lnlercepler banks also eul on seepage lrorri sail hkzs, and ean diverl early lsalledl overland now around sallparis, leliing laler lresh iloodwaier lrll ihe pans or shallow lahs kgadu drain5 or banks are inlendrd lo spill a lhin rheel n1 surplus (overflow) waier dawn a lrroad grassy slope, e her lor irrigalion or (u! deserlsl lo prevenl channel mm! and gidlying. niey are nonnally rnade lo asuh: 7.2a nlvEnsluu mums uni-is mus, mm M- imn warm lo nuns, m wum menann llov am! semi ll m sloiaurs Ynly arr pm or any rainvaler harvsnw-l mien M9472 minus 111 me A ironic slim an! end snowed w m channel Mk1. ihe ulnar women iry a ehain loirns a iii-roomy darn. uuxlnv mi channel In llood onl and impair land flammll 169