[POMPONIUS libro trigensimo quarto ad Sabinum. ] §41.1.30.prErgo si insula nata adcreuerit fundo meo et inferiorem partem fundi uendidero, ad cuius frontem insula non respicit, nihil ex ea insula pertinebit ad emptorem eadem ex causa, qua nec ab initio quidem eius fieret, si iam tunc, cum insula nasceretur, eiusdem partis dominus fuisset.
[POMPONIUS, On Sabinus, book 34] Therefore, if a newborn island has accreted to my estate, and I sell the lower part of the estate, to the front of which the island does not face, nothing of that island will belong to the buyer, for the same reason that it would not have become his even from the beginning, if he had already been the owner of that same part at the time when the island was born.
§41.1.30.1Celsus filius, si in ripa fluminis, quae secundum agrum meum sit, arbor nata sit, meam esse ait, quia solum ipsum meum priuatum est, usus autem eius publicus intellegitur.
Celsus the son says that if a tree grows on the bank of a river which is alongside my land, it is mine, because the soil itself is my private property, while its use is understood to be public.
et ideo cum exsiccatus esset alueus, proximorum fit, quia iam populus eo non utitur.
And therefore, when the riverbed has dried up, it becomes the property of the adjacent owners, because the public no longer uses it.
§41.1.30.2Tribus modis insula in flumine fit, uno, cum agrum, qui aluei non fuit, amnis circumfluit, altero, cum locum, qui aluei esset, siccum relinquit et circumfluere coepit, tertio, cum paulatim colluendo locum eminentem supra alueum fecit et eum alluendo auxit.
An island is formed in a river in three ways: first, when the river flows around land which was not part of the riverbed; second, when it leaves dry a place which was part of the riverbed and begins to flow around it; third, when by gradually depositing alluvion it has created an elevated place above the riverbed and increased it by accretion.
duobus posterioribus modis priuata insula fit eius, cuius ager propior fuerit, cum primum extitit: nam et natura fluminis haec est, ut cursu suo mutato aluei causam mutet.
In the two latter ways, the island becomes the private property of the person whose land was closer when it first emerged; for the nature of a river is such that by changing its course, it changes the legal status of the bed.
nec quicquam intersit, utrum de aluei dumtaxat solo mutato an de eo, quod superfusum solo et terrae sit, quaeratur, utrumque enim eiusdem generis est.
Nor does it make any difference whether the inquiry concerns only the change of the soil of the bed, or that which has been poured over the soil and land, for both are of the same nature.
primo autem illo modo causa proprietatis non mutatur.
In that first way, however, the status of ownership is not changed.
§41.1.30.3Alluuio agrum restituit eum, quem impetus fluminis totum abstulit.
Alluvion restores land which the violence of a river has entirely carried away.
itaque si ager, qui inter uiam publicam et flumen fuit, inundatione fluminis occupatus esset, siue paulatim occupatus est siue non paulatim, sed eodem impetu recessu fluminis restitutus, ad pristinum dominum pertinet: flumina enim censitorum uice funguntur, ut ex priuato in publicum addicant et ex publico in priuatum: itaque sicuti hic fundus, cum alueus fluminis factus esset, fuisset publicus, ita nunc priuatus eius esse debet, cuius antea fuit.
Therefore, if a piece of land which was between a public road and a river should be occupied by a flood of the river, whether it was occupied gradually or not gradually but by the same violence, if it is restored by the receding of the river, it belongs to the original owner; for rivers perform the function of censors, in that they adjudge property from private to public use, and from public to private. Accordingly, just as this estate, when it had become the riverbed, would have been public, so now it ought to be the private property of him to whom it formerly belonged.
§41.1.30.4Si pilas in mare iactauerim et supra eas inaedificauerim, continuo aedificium meum fit.
If I throw piles into the sea and build upon them, the building immediately becomes mine.
item si insulam in mari aedificauerim, continuo mea fit, quoniam id, quod nullius sit, occupantis fit.
Likewise, if I build an island in the sea, it immediately becomes mine, since that which belongs to no one becomes the property of the occupier.