Seite - 253 - in The Power of Urban Water - Studies in premodern urbanism

15 Human Impact onHydrology 253 Fig. 5:Hydrotopog- raphyofBamberg. Changing roleofwaters affects urbandesign Inthecourseof time, theimportanceofriversandwatercoursesfor transportationandtravelling changed.With flatboats,evenrathersmallcreekswerenavigable.Transportationbywaterways wasmuchmore effective than transportationon land.18 There are some indications that inland navigationwas important in the EarlyMiddle Ages. On the river Main, for example, a line of fortified sites seems tohavecontrolledandsupportedwater transportationon the river. In 796, a channelwas constructed, or at least attempted, in order to connect theDanube river system and theRhine/Main river system: theFossaCarolina.19 In theHighMiddleAges, during the Staufianperiod, land transportation gained in impor- tance.20 The famous Tabula Peutingerianawas copied during the 13th century from a late an- tiquemapshowing theRomanroads. Therewerealso someattempts, at least in Italy, to renew the obligations of adjoining owners to take on themaintenance and repair of roads.21 It is still a question in research as towhether therewere also technical innovations in land traffic, for example, the cambered wheel, the horse collar, or horseshoes. Dating innovations is a prob- lem.22 Horseshoes can be found in rather large quantities at medieval sites, whereas wooden wheels andhorse collarsmadeofwoodand leather are rarelypreserved.Acorrelationof these innovationwith 13th century’s changes needs to be researched. There are also very few dated medieval bridges to help to clearly define periods of intense bridge construction activities. In central Europe, there are at least some bridges dating to the Staufian period, some in rural contexts,someclosetotowns(Fig.6).Forexample, thebridgeacrosstheriverNeckaratNeckar- 18 Eckoldt 1984. 19 Ettel et al. 2014; Schmidt et al. 2018;Werther–Kröger 2017. 20 Szabó 1999. 21 Szabó 1977. 22 Cf. Schreg 2003; Schreg 2013b.